CHAPTERCONTENTS The structure-function continuum 1 Multiple Influences: biomechanical, biochemical and psychological 1 The structure and Homeostasis and heterostasis 2 OBJECTIVE AND METHODS 4 function of breathing NORMAL BREATHING 5 Respiratory benefits 5 Leon Chaitow The upper airway 5 Dinah Bradley Thenose 5 The oropharynx 13 The larynx 13 Pathological states affecting the airways 13 Normal posture and other structural THE STRUCTURE-FUNCTION considerations 14 Further structural considerations 15 CONTINUUM Kapandji's model 16 Nowhere in the body is the axiom of structure Structural features of breathing 16 governing function more apparent than in its Lung volumes and capacities 19 relation to respiration. This is also a region in Fascla and resplrstory function 20 which prolonged modifications of function - Thoracic spine and ribs 21 Discs 22 such as the inappropriate breathing pattern dis- Structural features of the ribs 22 played during hyperventilation - inevitably intercostal musculature 23 induce structural changes, for example involving Structural features of the sternum 23 Posterior thorax 23 accessory breathing muscles as well as the tho- Palpation landmarks 23 racic articulations. Ultimately, the self-perpetuat- NEURAL REGULATION OF BREATHING 24 ing cycle of functional change creating structural Chemical control of breathing 25 modification leading to reinforced dysfunctional Voluntary control of breathing 25 tendencies can become complete, from The autonomic nervous system 26 whichever direction dysfunction arrives, for Sympathetic division 27 Parasympathetic division 27 example: structural adaptations can prevent NANC system 28 normal breathing function, and abnormal breath- THE MUSCLES OF RESPIRATION 30 ing function ensures continued structural adap- Additional soft tissue influences and tational stresses leading to decompensation. connections 31 insplratory and expiratory muder, 31 Restoration of normal function requires Gait influences 32 restoration of adequate mobility to the structural component and, self-evidently, maintenance of Upper thoracic muscles 33 Thoracic musculature 34 any degree of restored biomechanical integrity NOTES ON SPECIFIC MUSCLES 35 requires that function (how the individual Spinalis thoracis 35 breathes) should be normalized through re- Semispinalis thoracis 35 education and training. Multifidi 35 Rotatores longus and brevis 35 Spinal musculature: implications for thoracic function 36 MULTIPLE INFLUENCES: Muttifidus and the abdominals 36 Serratus posterior superior 36 BIOMECHANICAL, BIOCHEMICAL, Serratus posterior inferior 36 AND PSYCHOLOGICAL Levatores costarum iongus and brevis 37 lntercostals 37 The area of respiration is one in which the inter- Interior thorax 38 action between biochemical, biomechanical, and Transversus thoracis 39 psychosocial features is dramatically evident

1 2 MULTtDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

Other catalysts which may impact on breathing function include environmental factors (altitude, humidity, etc.). Even factors such as where an individual is born may contribute to subsequent breathing imbalances: 'People who are born at high altitude have a diminished ventilatory response to hypoxia that is only slowly corrected by subsequent residence at sea level. Conversely, those born at sea level who move to high altitudes retain their hypoxic response intact for a long time. Apparently therefore ventilatory response is determined very early in life' (West 2000). How we breathe and how we feel are inti- mately conjoined in a two-way loop. Feeling anxious produces a distinctive pattern of upper- chest breathing which modifies blood chemistry, leading to a chain reaction of effects, inducing anxiety, and so reinforcing the pattern which pro- duced the dysfunctional pattern of breathing in the first place. Even when an altered pattern of breathing is the result of emotional distress, it will eventually produce the structural, biomechanical changes which are described below. This suggests that when attempting to restore normal breathing - by means of re-education and exercise for example - both the psychological initiating factors and the structural compensation patterns Figure 1.1 A Homeostasis. B Heterostasis. (Reproduced need to be addressed. (The psychological effects with kind permission from Chaitow 1999.) of breathing dysfunction are covered in greater detail in Chapter 5.) (Fig. 1.1A, 1.1B). Inappropriate breathing can result directly from structural, biomechanical causes, Homeostasis and heterostasis such as a restricted thoracic spine or rib immobility or shortness of key respiratory muscles. The body is a self-healing mechanism. Broken Causes of breathing dysfunction can also have bones mend and cuts usually heal, and most a more biochemical etiology, possibly involving health disturbances - from infections to digestive an allergy or infection which triggers narrowing upsets - get better with or without treatment of breathing passages and subsequent asthmatic- (often faster without!), and, in a healthy state, type responses. Acidosis resulting from condi- there exists a constant process for normalization tions such as kidney failure will also directly alter and health promotion. This is called homeostasis. breathing function as the body attempts to However, the homeostatic functions (which reduce acid levels via elimination of C02through include the immune system) can become over- the means of hyperventilation. whelmed by too many tasks and demands as a The link between psychological distress and result of any, or all, of a selection of negative breathing makes this another primary cause of impacts, including nutritional deficiencies, accu- many manifestations of dysfunctional respir- mulated toxins (environmental pollution, either ation. Indeed, it is hard to imagine examining a as food or inhaled, in medication, previous or person suffering from anxiety or depression current use of drugs, etc.), emotional stress, without breathing dysfunction being noted. recurrent or current infections, allergies, modi- THE STRuefilRE AND FUNCTION OF BREATHING 3

fied functional ability due to age, or inborn the pressure off the defense mechanisms while factors, or acquired habits involving poor the body focuses on its current repair needs. posture, breathing imbalances and/or sleep 2. Enhancing, improving, modulating the disturbances, and so on and on ... (Fig. 1.2). defense and repair processes by a variety of At a certain point in time the adaptive homeo- means, sometimes via specific intervention static mechanisms break down, and frank illness and sometimes involving non-specific, - disease - appears. At this time the situation has constitutional methods. modified from homeostasis to heterostusis, and at 3. Treating the symptoms while making sure that this time the body needs help - treatment. nothing is being done to add further to the Treatment can take a number of forms, which are burden of the defense mechanisms. usually classifiable as involving one of three Not all available therapeutic measures need broad strategies: to be employed, because once the load on the 1. Reducing the load impacting the body by adaptation and repair processes has reduced taking away as many of the undesirable adap- sufficiently, a degree of normal homeostatic tive factors as possible (by avoiding allergens, self-regulating function is automatically restored, improving posture and breathing, learning and the healing process commences. stress coping tactics, improving diet, using supplements if called for, helping normalize Therapy as a stress factor sleep and circulatory function, introducing a detoxification program if needed, dealing A corollary to the perspective of therapy being with infections) and generally trying to keep aimed at the 'removal of obstacles to self-healing'

pesticides, etc. heavy metals Possible nutrient petrochemicals deficiencies: self-generated Lifestyle factors: vitamins via infection poor sleep patterns conditions minerals iaterogenic inadequate or excessive EFAs influences, etc. exercise Neural and/or limbic i alcohol, tobacco usage I svstem malfunction h\ / /I I social and medical drugs I bacterial I \U fungal viral personality traits parasitic, etc. powerlessness L- anxiety Genetically interpersonal issues inherited tendencies: hypermobility genetic inscription influences on hormonal function Endocrine imbalance Multiple current symptoms: Functional problems: \' pain, fatigue, insomnia, IBS, - hyperventilation digestive, allergic, recurrent - digestive enzyme Trauma - physical and/or infections, genitourinary, etc. deficit, etc. psychological

When homeostatic adaptive capacity is exhausted treatment calls for: 1. Restoration of immune competence, enhancement of defence capabilities, support of repair functions 2. Reduction of as many of the multiple interacting stressors impacting the individual as possible 3. Attention to symptoms (ideally without creating new problems). Figure 1.2 Multiple stressors in fibromyalgia. (Reproduced with kind permission from Chaitow 1999.) 4 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS is that, since almost any form of ’treatment’ been established. This commonly requires the involves further adaptive demands, therapeutic removal of causative factors, if identifiable, interventions need to be tailored to the ability of and, if possible, the rehabilitation of habitual, the individual to respond to the treatment. acquired dysfunctional breathing patterns, and, Excessive adaptive demands made of an indi- in order to achieve this most efficiently, some vidual, already in a state of adaptive exhaustion, degree of structural mobilization to restore the are bound to make matters worse. machinery of breathing towards normality. A clinical rule of thumb adopted by one of the If rehabilitation is attempted without taking authors (LC) is that the more ill a patient is, the account of etiological features or maintaining more symptoms are displayed, and the weaker is features - restricted rib articulations, shortened the evidence of vitality, the lighter, gentler, and thoracic musculature, etc. - results will be less more ’constitutional’ (whole person) the inter- than optimal. vention needs to be. (See Ch. 4 for discussion of An example of extreme breathing pattern alter- adaptation exhaustion, and Zink‘s protocols.) ation is hyperventilation. Hyperventilation and Whereas a robust, vital individual might well its effects occupy a major part of the book. It will respond positively to several simultaneous ther- also be necessary to explore the widespread gray apeutic demands, for example a change in diet area in which normal patterning is clearly absent, together with medication, bodywork, and reha- even though patent hyperventilation is not bilitation exercises, someone who is more frail demonstrable. and less vital might well collapse under such an A perspective needs to be held in which func- adaptive therapeutic assault. For the frail patient, tion and structure are kept in mind as dual, inter- a single modification or therapeutic change dependent features. The thoracic cage can be might be called for, with ample time allowed to thought of as a cylindrical structure housing most adapt to the change (whether this involves major organs - lungs, heart, liver, spleen, pancreas, exercise, posture, diet, bodywork, medication, kidneys. The functions associated with the thorax psychological intervention, or anything else). (or with muscles attached to it) include respir- In any given case it is necessary to focus atten- ation, visceral activity, stabilization, and move- tion on what seems to be the likeliest and easiest ment (and therefore posture) of the head, neck, targets (perhaps using a team approach in which ribs, spinal structures, and upper extremity. more than one therapist/therapy is being The causes of dysfunctional breathing patterns utilized) which will achieve this desirable end. In will be seen to possibly involve etiological fea- one person this may call for rehabilitation exer- tures which may in nature be largely biomechan- cises accompanied by psychotherapy/counseling; ical (for example post-surgical or postural in another, dietary modification and stress reduc- factors), biochemical (including allergic or infec- tion could be merited; while in another, enhance- tion factors), or psychosocial (chronic emotional ment of immune function and structural states such as anxiety and anger). Etiology may mobilization using bodywork and exercise may also involve combinations of these factors, or be considered the most appropriate interventions. established pathology may be the cause. In many The ‘art’ of health care demands the employment instances, altered breathing patterns, whatever of safe and appropriate interventions to suit the their origins, are maintained by nothing more particular needs of each individual. sinister than pure habit (Lum 1994). Where pathology provides the background to altered breathing patterns, the aim of this book is not to explore these disease states (e.g. asthma, OBJECTIVES AND METHODS cardiovascular disease) in any detail except insofar as they impact on breathing patterning (for The focus of this book is on normal versus abnor- example where airway obstruction causes normal mal respiratory patterns (function),and how best nasal inhalation to alter to mouth breathing). The to restore normality once an altered pattern has changes which concern this text are largely func- THE STRUCTURE AND FUNCTION OF BREATHING 5 tional in nature rather than pathological, although oropharynx, laryngeal pharynx, larynx, trachea, the impact on the physiology of the individual of bronchi, and bronchioles. Disease and dysfunc- an altered breathing pattern such as hyperventila- tion can affect any of these segments and cause tion can be profound, possibly resulting in severe abnormal breathing patterns, and it is important health problems ranging from anxiety and panic to recognize and treat any such conditions before attacks to fatigue and chronic pain. attempting to correct abnormal patterns such as It is axiomatic that in order to make sense of hyperventilation. abnormal respiration, it is essential to have a rea- sonable understanding of normality. As a foun- dation for what follows, this chapter will outline The nose the basic characteristics of normal breathing. The The nose is an intriguing characteristic facial biochemical and alveolar processes involved in feature, taking on a variety of shapes and sizes, respiration (as distinct from the biomechanical and changing with age. It is a complex structure process of breathing) will be covered in later with a number of vital functions: chapters. 0 Air enters each narrow nostril (the external naris), streaming into a tall cave. 0 Further turbulence is created by three curved NORMAL BREATHING bony plates (termed conchae) on the outer wall. These increase the mucosal surface area. 0 Bristling hairs (vibrzssae) inside the nostril trap RESPIRATORY BENEFITS large floating debris, while fine dust is Optimal respiratory function offers a variety of arrested by a forest of fine hairs and a film of benefits to the body: mucus floating on the nasal mucosa. 0 In this fashion, the air is filtered, warmed, and 0 It allows an exchange of gases involving humidified before leaving the nose via large - the acquisition of oxygen (OJ apertures (chounae) above the hard palate. - the elimination of carbon dioxide (COJ. 0 The mucosa has a rich blood supply providing 0 The efficient exchange of these gases enhances heat and fluid, and is thickest over the tips of cellular function and so facilitates normal per- the conchae. formance of the brain, organs, and tissues of 0 During (for instance) a cold, the mucous mem- the body. brane can swell, blocking the passage of air. 0 It permits normal speech. 0 Air in the upper reaches of the tall cave can 0 It is intimately involved in human non-verbal enter attics (cool air sinuses) through narrow expression (sighing, etc.). openings (ostiu). Here, warming and further 0 It assists in fluid movement (lymph, blood). filtering takes place. 0 It helps maintain spinal mobility through 0 These sinuses are named the frontal behind the regular, mobilizing, thoracic cage movement. forehead, the maxillary behind the cheek, and 0 It enhances digestive function via rhythmic the ethmoid and sphenoid under the bridge of positive and negative pressure fluctuations, the nose. when diaphragmatic function is normal. 0 The dust-laden mucus can work forward Any modification of breathing function from the toward the nostrils, where it dries and can be optimal is capable of producing negative effects removed. on these functions. 0 There is a backward flow as well, and this col- lection can be swallowed or coughed out. Box 1.1 gives details of the osseous and muscu- THE UPPER AIRWAY (Figs 1.3-1.10) lar components of the nasal apparatus, and To enter the air sacs of the lungs, air journeys Chapter 6 describes palpation/treatment exer- through a series of passages: nose, nasopharynx, cises relating to them. 6 MULTIDISCIPLINARY APPROACHES TO BREATHING PATERN DISORDERS THE STRUCTURE AND FUNCTION OF BREATHING 7 8 MULTIDISCIPLINARY APPROACHES TO BREATHING PATERN DISORDERS THE STRUClllRlE AND FUNCTION OF BREATHING 9

Box 1.1 (Continued)

being a virtual continuation of the ethmoids Levator labii superioris arises from the frontal portion of perpendicular plate the maxilla and runs obliquely laterally and inferior to The inferior aspect of the vomer articulates with the insert partly in the greater alar cartilage and partly into maxillae and the palatines the upper lip. Its actions are to raise and evert the 0 There is a cartilaginous articulation with the nasal upper lip and dilate the nostrils septum Associations and influences Muscular attachments The zygomata offer protection to the temporal region There are no direct muscular attachments. and the eye and, like the ethmoid and vomer, act as shock absorbers which spread the shock of blows to the Associations and influences face. The zygomatlcofacial and zygomaticotemporal As with the ethmoid, this is a pliable, shock-absorbing foramina offer passage to branches of the 5th cranial structure which conforms and deforms, depending on the nerve (maxillary branch of trigeminal). demands made on it by surrounding structures. The Treatment protocols for the zygomata will be found in mucous membrane covering the vomer assists in warming Chapter 6. air in nasal breathing. Treatment protocols for the vomer will be found in Max///a(see Fig. 1.6) Chapter 6. This extremely complex bone is made up of: The body which houses an air sinus zygomata A superior concave orbital surface which forms part of Each zygoma has: the floor of the eye socket A central broad curved malar surface 0 An infraorbital foramen and canal which offers passage A concave ‘corner’ which makes up most of the lateral, to part of the 5th cranial (trigeminal) nerve and to the and half of the inferior, border of the orbit infraorbital artery An anteroinferior border which articulates with the 0 An anterior spine to which the nasal septum attaches maxilla 0 An aperture (maxillary hiatus) on the medial wall of the A superior jutting frontal process which articulates air sinus which is largely covered by the palatines superiorly via interdigitations with the temporal portion posteriorly and the inferior conchae anteriorly of the frontal bone and posteriorly with the greater wing 0 A jutting superior projection which articulates by of the sphenoid interdigitationwith the frontal bone A posteromedial border which articulates via 0 A notch (ethmoid notch) on the medial surface of this interdigitations with the greater wing above and the projection which articulates with the middle conchae orbital surface of the maxilla below A lateral zygomatlc process which articulates with the zygoma at the dentate suture Articulations An inferiorly situated palatine process which forms The zygoma articulates: most of the hard palate (anterior portion) With the temporals via the zygomatic bone where it An inferiorly situated central suture for articulation with meets the zygomatic process at the its pair, the intermaxillary suture zygomaticotemporal suture A suture which runs transversely across the palate 0 With the frontal bone at the frontozygomatic suture where the maxillary palate and the palatine bone 0 With the maxillae at the zygomaticomaxillary suture articulates (maxillopalatine suture) With the sphenoid at the zygomatic margin A central (incisive) canal, placed inferiorly and anteriorly, for passage of the nasopalatine nerve Muscular attachments The alveolar ridge, an anteriorhnferior construction for Masseter attaches from the zygomatic arch both housing the teeth superficially and deep, running superficially to the lower lateral ramus of the mandible and deep to the coronoid process and upper ramus of the mandible Articulations Zygomaticus minor and major extend from the As described above, the maxillae articulate at numerous zygomatic bone to the upper lip and to the angle of the complex sutures with each other, as well as with the teeth mouth (involved in raising the upper lip and in they house, the ethmoid and vomer, the palatines and the laughing) zygomata, the inferior conchae and the nasal bones, the Orbicularis oculi is a broad, flat muscle which forms frontal bone and the mandible (by tooth contact), and part of the eyelids, surrounds the eye and runs into the sometimes with the sphenoid. cheeks and temporal region. Parts are continuous with occipitofrontalis. It is the sphincter muscle of the Muscular attachments eyelids, causing blinking and, in full contraction, Medial pterygoid runs from the palatine bones and drawing the skin of the forehead, temple, and cheek the medial surface of the lateral pterygoid plate of the toward the medial corner of the eye sphenoid and the tuberosity of the maxilla to the 10 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS THE STRUCTURE AND FUNCTION OF BREATHING 11

Box 1.1 (Continued)

lateral ramus of the mandible and deep to the coronoid 0 A nasal crest which is a continuation of the suture process and upper ramus of the mandible which links the two palatines (median palatine suture) 0 Buccinator is a thin four-sided muscle which forms part 0 A sulcus which houses the greater palatine nerve and of the cheek occupying the space between the maxilla the descending palatine artery and the mandible It attaches to the alveolar processes of the maxilla and the mandible opposite the three Arf/cu/at/ons molar teeth Its fibers converge toward the angle of the 0 The concha1 crest for articulation with the inferior nasal mouth and the lips Its action is to compress the concha cheeks against the teeth during chewing and it is 0 The ethmoidal crest for articulation with the middle involved in the act of blowing (buccinator means nasal concha trumpeter) The maxillary surface has a roughened and irregular Of lesser importance but also attaching to the maxillae surface for articulation with the maxillae are various muscles many of which have to do with 0 The anterior border has an articulation with the inferior facial expression and with mouth movement in eating, nasal concha such as orbicularis oris depressor anguli oris, levator 0 The posterior border is serrated for articulation with the labii superioris levator labii superioris alaeque nasi, medial pterygoid plate of the sphenoid levator anguli oris, nasalis depressor septi nasi, The superior border has an anterior orbital process risorius which articulates with the maxilla and the sphenoid There are also strong influences from the muscles of concha, and a sphenoidal process posteriorly which the tongue although these do not directly attach to the articulates with the sphenoidal concha and the medial maxillae pterygoid plate, as well as the vomer 0 The median palatine suture joins the two palatines Associabons and mfluences Because of the involvement of both the teeth and the air Muscular attachments sinuses, the causes of pain in this region are not easy to The medial pterygoid is the only important muscular diagnose These connections (teeth and sinuses), as well attachment It attaches to the lateral pterygoid plate and as the neural structures which pass through the bone, palatine bones running to the medial ramus and angle of plus its multiple associations with other bones and its the mandible vulnerability to trauma, make it one of the key areas for therapeutic attention where problems associated with the Associabons and influences area are concerned 0 These delicate shock-absorbing structures with their multiple sutural articulations spread force in many Treatment protocols for the maxillae will be found in directions when any is exerted on them Chapter 6 0 They are capable of deformation and stress transmission and their imbalances and deformities Palatines usually reflect what has happened to the structures This complex extremely thin hook-shaped structure with which they are articulating includes Great care needs to be exercised in any direct contact A perpendicular plate which forms part of the wall for on the palatines (especially cephalad pressure) the maxillary sinus because of their extreme fragility and proximity to the A horizontal plate which makes up the posterior aspect sphenoid in particular, as well as to the nerves and of the hard palate as well as the floor of the nose blood vessels which pass through them (see A pterygoid process which articulates with the cautionary note below) sphenoid An ethmoidal crest which articulates with the middle conchae of the ethmoid A CAUTION: No guidelines are presented in this text A ridge which articulates with the inferior conchae for treatment involving the palatines due to reported An orbital process which articulates with the maxilla, iatrogenic effects resulting from inappropriate degrees of ethmoid, and sphenoid pressure being applied (McPartland 1996) A sphenoid process which articulates with the vomer and the inferior aspect of the sphenoid

Diaphragmatic and intercostal breathing widen, but when larger volumes of air are Breathing through the nose involves overcoming a required the person resorts to mouth breathing, resistance, and this favours the slow, rhythmic, where there is much less resistance to flow. This diaphragmatic breathing of sleep, rest, and quiet breathing involves the intercostal and anterior activity. As exercise increases the nostrils at first neck muscles and is termed ‘intercostal breathing’. 12 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

Figure 1.7 Sagittal section through the nose, mouth, pharynx, and larynx. Where it divides the skull and the brain, the section passes slightly to the left of the median plane, but below the base of the skull it passes slightly to the right of the median plane. (Reproduced with kind permission from Gray 1989.)

of smell Sense activate the receptor cell below. An impulse is The sense of smell, the second function, is sent along the nerve fiber to the brain for deci- served by an olfactory membrane lining the roof phering, recognition, and initiating the appro- of the ethmoid sinuses. Protruding among sup- priate response - for example irritating porting cells are tiny buttons, each with three to substances can cause violent sneezing which four fine hairs lying in a special secretion. expels the offensive material. In humans there is Turbulence ensures that the scent of roses, for a further mechanism elsewhere in the nose for example, or the odor of a meal cooking, persists, the recognition of powerful and dangerous sub- enabling the cilia to sense the stimulus and stances such as smoke and noxious chemicals THE STRUCTURE AND FUNCTION OF BREATHING 13 which evoke violent alarm, coughing, and tonsils are part of the defense system of the avoidance behavior. The sense of smell is much upper airway. more sophisticated and sensitive in the dog, The laryngeal pharynx lies between the which has a much larger area of olfactory mem- epiglottis above, and the cricoid cartilage of the brane than man. larynx below, merging with the larynx in front and the esophagus behind. Protective function Swall0 wing A third function of the nose is as a defence against both viral and bacterial infections, protecting the In the first, voluntary, stage of swallowing the lungs and the rest of the body against these front of the tongue is raised to press against the organisms. The first reaction to invasion is a vas- hard palate, pushing back the bolus of food to the cular engorgement, bringing phagocytes into the soft palate, which descends to grip the bolus. nasal mucosa to engulf the invading organisms. With the rising of the back of the tongue, the food The blood also brings cells which stimulate and bolus is propelled into the oropharynx. Here the secrete antibodies against the invaders. The involuntary second stage ensues. The soft palate debris of phagocytes with their contents is camed rises to close off the nasopharynx. The epiglottis via the lymphatics to small satellite lymph nodes. is bent back to close off the entry to the larynx In many cases the infection is limited to a cold in and the food bolus slips down into the esopha- the nose, a tonsillitis, or a pharyngitis. gus, partly by gravity and partly by the action of the constricture muscles of the pharynx. Tear duct drain into the nose The larynx The nasopharynx has a curved, sloping roof. Its floor is made up of a bony hard palate in the The larynx is the next segment in the air pas- front and a soft palate behind. The soft palate sages, joining the pharynx with the trachea. In its ends in the uvula. In swallowing and vomiting, wall are nine cartilaginous plates with connect- the soft palate and uvula rise to cut off the nasal ing muscles. The cavity has an upper pair of cavity. On each side wall is the opening of the vestibular folds and a lower set, termed the vocal eustachian tube, draining the middle ear and chords, which can be more tightly brought equalizing the pressure with the external atmos- together. The whole structure forms a mecha- phere. In childhood the opening is surrounded nism to produce speech by opposing the vocal by the adenoids, a collection of lymphoid tissue. folds to varying degrees. Alternatively the folds may be completely closed off to protect the The oropharynx airway from fluid and food or to enable the lungs to build up pressure to cough out sputum. The oropharynx lies between the tip of the uvula Air proceeds to the trachea, dividing into right above, and, below, the epiglottis, a cartilaginous and left bronchi and on through diminishing flap at the back of the tongue. The mouth opens orders of bronchi and bronchioles to the terminal into the oropharynx (Fig. 1.7). On each lateral air sacs where gaseous exchange takes place. wall is a recess, housing the tonsil, which can vary in size. Tonsils are large in childhood, when PATHOLOGICAL STATES AFFECTING recurrent infection and inflammation favor THE AIRWAYS increased size. On the medial surface of each tonsil are 12-15 orifices of the narrow tonsilar Chronic obstruction of the nose and oropharynx crypts lined with stratified squamous epithelium can arise from a deviated nasal septum, exuber- with invading lymphocytes. Behind these are ant distorted conchae, enlarged adenoids, hay germinal centers, generating lymphocytes. The fever, cluster headaches, nasopharyngeal tumors, 14 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

~ or Wegener’s granulomatosis. Obstruction respiratory function so that dysfunction can be increases the resistance to airflow, necessitating more easily identified. Apart from standard func- intercostal breathing and a switch to mouth tional examination, it is also important that prac- breathing. The patient should be referred back to titioners and therapists acquire the ability to a general practitioner, or to an ear, nose, and assess by observation and touch, relearning skills throat surgeon, or perhaps an allergist. In obese familiar to former generations of ’low-tech’ people, redundancy and laxity of the mucosal health care providers. Assessment approaches folds can give rise to laryngeal obstruction and will be outlined in Chapters 6 and 7. cause sleep apnea or the obstructive sleep syn- drome. Tumors of the vocal chords can cause Is there such a thing as an optimal breathing laryngeal obstruction. In acromegaly, where pattern? there is a pituitary tumor overproducing growth hormone, the vestibular folds enlarge and tend to If structural modifications result from, and re- obstruct breathing. A previous tracheotomy can inforce, functional imbalances (see Ch. 4 in par- give rise to a tracheal stenosis. Chronic, inade- ticular) in respiration as in other functions, it quately-treated asthma causes spasm of the is of some importance to establish whether an bronchioles, producing an expiratory wheeze optimal, ideal, state is a potential clinical reality. and breathlessness. Lung tumors are another Since breathing function is, to a large extent, cause of breathlessness, while emphysema and dependent for its efficiency on the postural and heart disease are more common causes. structural integrity of the body, the question can The therapist who concentrates on psychological be rephrased: ‘Is there an optimal postural state?’ causes and on correcting abnormal breathing pat- (Fig. 1.8). terns in these patients is unlikely to succeed, since the major factor is not psychological but physical, is often life-threatening, and requires precise diag- nosis and treatment. Such patients should be referred to an appropriate specialist - a general physician or an expert in respiratory diseases.

NORMAL POSTURE AND OTHER STRUCTURAL CONSIDERATIONS It is a truism worth repeating that in order to appreciate dysfunction, a clear picture of what lies within normal functional ranges is needed. For normal breathing to occur, a compliant, elastic, functional state of the thoracic structures, both osseous and soft tissue, is a requirement. If restrictions are present which reduce the ability of the rib cage to appropriately deform in response to muscular activity and altered pres- sure gradients during the breathing cycle, com- pensating adaptations are inevitable, always at the expense of optimal function. A B C In manual medicine it is vital that practitioners and therapists have the opportunity to evaluate Figure 1.8 Balanced posture (A) compared with two patterns of musculoskeletal imbalance which involve fascia1 and palpate normal individuals with pliable and general tissue and joint adaptations. (Reproduced with musculature, mobile joint structures, and sound kind permission from Chaitow 1996a.) THE STRUCTURE AND FUNCTION OF BREATHING 15

Is there an ideal posture? Further structural considerations Kuchera & Kuchera (1997) describe what they As described above, the cylindrical thoracic cage consider an ideal posture: houses most major organs - the lungs, the heart, the liver, the spleen, the pancreas, and the Optimal posture is a balanced configuration of the kidneys. It has a number of functions associated body with respect to gravity. It depends on normal arches of the feet, vertical alignment of the ankles, with it (or with its muscular attachments), and horizontal orientation (in the coronal plane) of including visceral support and influence, stabi- the sacral base. The presence of an optimum posture lization, and movement (and therefore posture) suggests that there is perfect distribution of the body of the head, neck, ribs, spinal structures, and mass around the centre of gravity. The compressive upper extremity. force on the spinal disks is balanced by ligamentous tension: there is minimal energy expenditure from Since the volume of the lungs is determined by postural muscles. Structural and functional stressors changes in the vertical, transverse, and antero- on the body, however, may prevent achievement of posterior diameters of the thoracic cavity, the optimum posture. In this case homeostatic mecha- nisms provide for ’compensation’ in an effort to ability to produce movements which increase provide maximum postural function within the any of these three diameters (without reducing existing structure of the individual. Compensation is the others) should increase respiratory capacity, the counterbalancing of any defect of structure or under normal circumstances (i.e. if the pleura are function. intact). Inhalation and exhalation involve expansion This succinct description of postural reality highlights the fact that there is hardly ever an and contraction of the lungs themselves, and this example of an optimal postural state, and, by takes place: implication, of optimal respiratory function. 0 By means of a movement of the diaphragm, However, there can be a well-compensated which lengthens and shortens the vertical dia- mechanism (postural or respiratory) which, meter of the thoracic cavity. This is the normal despite asymmetry and compensations, func- means of breathing at rest. This diameter can be tions as close to optimally as possible. This is clearly an acceptable ‘ideal’ and approaches the further increased when the upper ribs are raised reality normally observed in most symptom-free during forced respiration, where the normal people. Where dysfunction is apparent, or symp- elastic recoil of the respiratory system is insuffi- toms are evident, a degree of adaptive overload cient to meet demands. This brings into play the will have occurred. accessory breathing muscles, acting rather like a If postural features are a part of such a reserve tank, including sternocleidomastoid, the scenario it is necessary to take account of emo- scalenes, and the external intercostals. tional states, occupational and leisure influ- 0 By means of movement of the ribs into ele- ences, proprioceptive and other neural inputs, vation and depression which alters the diameters inborn characteristics (for example an anatom- of the thoracic cavity, vertical dimension is ical short leg), as well as habitual patterns of use increased by the actions of diaphragm and (for example upper-chest breathing), along with clinical evidence of joint and soft tissue restric- scalenes. Transverse dimension is increased with tions and imbalances. It is also necessary to be the elevation and rotation of the lower ribs able to evaluate and assess patterns of use which (‘bucket handle’ rib action) involving the indicate just how close to, or far from, an optimal diaphragm, external intercostals, levatores postural or respiratory state the individual is. costarum. Elevation of the sternum is provided Examples of useful structural and functional by upwards pressure due to spreading of the ribs assessment methods will be found in Chapters 4, (‘pump handle’ rib action), and the action of 5, 6, and 7. sternocleidomastoid and the scalenes. 16 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

Kapandji’s model STRUCTURAL FEATURES OF BREATHING Kapandji (1974), in his discussion of respiration, has described a respiratory model. A crude The biomechanical structures which comprise model can be created by replacing the bottom of the mechanism with which we breathe include a flask with a membrane (representing the the sternum, ribs, thoracic vertebrae, inter- diaphragm), and providing a stopper with a tube vertebral discs, costal joints, muscles, and set into it (to represent the trachea) and a balloon ligaments. Structural and functional aspects of all within the flask at the end of the tube (represent- of these are summarized below (see also ing the lungs within the rib cage). By pulling Figs 1.9-1.12). down on the membrane (the diaphragm on Put simply, the efficiency of breathing/respira- inhalation), the internal pressure of the flask tion depends upon the production of a pumping (thoracic cavity) falls below that of the atmos- action carried out by neuromuscular and skeletal phere, and a volume of air of equal amount to exertion. The effectiveness of the pumping that being displaced by the membrane rushes mechanism may be enhanced or retarded by into the balloon, inflating it. The balloon relaxes the relative patency, interrelationships, and when the lower membrane is released, elastically efficiency of this complex collection of structures recoiling to its previous position as the air and their activities: escapes through the tube. The human respiratory system works in a 0 On inhalation, air enters the nasal cavity or similar manner, while at the same time being mouth and passes via the trachea to the bronchi, much more complex and highly coordinated: which separate to form four lobar bronchi and subsequently subdivide into ever narrower During inhalation, the diaphragm displaces bronchi until ’At the 11th subdivision, the caudally, pulling its central tendon down, airway is called a bronchiole’ (Naifeh 1994). thus increasing vertical space within the 0 Normal nasal function in respiration includes thorax. filtration of the air as well as warming and As the diaphragm descends, it is resisted by humidifying it as it passes towards the the abdominal viscera. trachea. This function is lost if there is obstruc- At this point, the central tendon becomes tion of the airways involved, or in chronic fixed against the pressure of the abdominal mouth breathers. Quiet inhalation function cavity, while the other end of the diaphragm’s fibers pull the lower ribs should be effortless if all the mechanical char- cephalad, so displacing them laterally. acteristics of the structures involved are As the lower ribs are elevated and optimal and airways are patent. Altered com- simultaneously moved laterally, the sternum pliance (the expansibility potential of the moves anteriorly and superiorly. lungs and thoracic cage), tissue resistance Thus, by the action of the diaphragm alone, (how elastic, fibrotic, mobile the structures the vertical, transverse, and anteroposterior are), and airway resistance all increase the diameters of the thoracic cavity are amount of effort required to inhale. increased. 0 The structure of the trachea and bronchi If a greater volume of breath is needed, other includes supporting rings which are made up accessory muscles must be recruited to assist. of varying proportions of cartilage - for rigid- Abdominal muscle tone provides correct positioning of the abdominal viscera so that ity - and elastic muscle. While the wider and appropriate central tendon resistance can more cephalad trachea has a larger proportion occur. If the viscera are displaced, or of cartilage, the narrower and more caudad abdominal tone is weak and resistance is bronchioles are almost entirely elastic. reduced, lower rib elevation may be impeded 0 Gas exchange takes place in the alveoli (air and volume of air intake will be reduced. sacs) which are situated toward the end of the THE STRUCTURE AND FUNCTION OF BREATHING 17

True ribs

Sternum

False ribs

I Xiphoid process Floating ribs

Figure 1.9 Anterior view of the thoracic cage. (Reproduced from Seeley et al 1995.)

Vertebral extremity Neck

Non-articular part

Angle

Transverse process

Sternal Body (shaft) A extremity B Figure 1.10 The rib and its vertebral articulation. A Articulation with the thoracic vertebra. B Posterior view of the rib. (Reproduced from Beachey 1998.) 18 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

bronchioles, mainly in the alveolar ducts (Fig. 1.13). These air sacs have fine membrane- ous walls surrounded by equally thin-walled capillaries which allow gas exchange to occur. 0 In order for the lungs to expand and contract, the thoracic cavity lengthens and shortens due to the rise and fall of the diaphragm as the ribs elevate and depress to produce an increase and decrease in the anteroposterior diameter of the rib cage. Any restrictions imposed by joint or soft tissue dysfunction will retard the efficiency of this pumping process. Some of the thoracic activities described are under muscular control, whereas others result from elastic recoil: ‘When the chest wall is Figure 1.11 Chest wall dimension changes during breathing. opened during surgery the lungs have a contin- The left column illustrates the pump-handle movement of the ual elastic tendency to collapse, pulling away ribs. The right column illustrates the bucket-handle movement. (Reproduced from Beachey 1998.) from the chest wall, whereas the chest wall tends

Figure 1.12 Muscles of ventilation, including accessory muscles. (Reproduced from Beachey 1998.) THE STRucfLlRE AND FUNCTION OF BREATHING 19

breathing, where muscular activity is used to overcome airway resistance, elastic recoil must also be overcome during inhalation. During exhalation from deeper breathing, the tendency for the thorax to increase its volume also has to be overcome by muscular effort. If the accessory breathing muscles become shortened or fibrotic they negatively influence the efficiency of these processes.

LUNG VOLUMES AND CAPACITIES Total lung capacity (TLC) is the amount of air the lung can contain at the height of maximum inspiratory effort. All other lung volumes are natural subdivisions of TLC. Residual volume (RV) is the amount of air remaining within the lung after maximum exhalation. Inhaled at birth, it is not exhaled until death because the rib cage prevents total lung collapse. The volumes and capacities within these two limits are described in Figure 1.14. Lung volumes are measured in a variety of ways. From simple hand-held peak expiratory flow (PEF) meters used by patients with asthma to record air flow resistance to sophisti- Figure 1.13 Branching of the conducting and terminal cated laboratory equipment to establish both airways. Alveoli first appear in the respiratory bronchioles marking the beginning of the respiratory or gas exchange static and exercise lung capacities, volumes, zone. 6R bronchus, 6L bronchiole, T6L terminal bronchiole, and pressures, accurate information can be R6L respiratory bronchiole, AD alveolar duct, AS alveolar gained as to lung health or otherwise. For space, and Zorder of airway division. (Reproduced from Beachey 1998.) instance, vital capacity (VC) may be greatly reduced by limited expansion (restrictive disease) or by an abnormally large tidal to recoil outwards. These movements, in oppo- volume (chronic obstructive airways disease or site directions, are responsible for the develop- during asthma attacks). During vigorous exer- ment of negative pleural pressure when the cise, tidal volume (Vt) may increase to half the respiratory system functions in the intact state’ VC to maintain adequate alveolar ventilation. (DAlonzo & Krachman (1997)). In quiet breath- Limitation of exercise capacity is often the first ing, at the end of exhalation, with the lungs par- sign of early lung disease that limits VC (Berne tially inflated, an elastic recoil occurs which & Levy 1998, p. 530). contracts and starts to empty the lungs. This passive elastic recoil which empties the lungs in Respiratory function (breathing) therefore quiet breathing should not involve any muscular demonstrably depends on the efficiency with activity. If more air is required than can be intro- which the structures constituting the pump mech- duced by quiet breathing, accessory breathing anisms operate. At its simplest, for this pump to muscles come into play. And with such deeper function optimally, the thoracic spine and the 20 MULTIDISCIPLINARY APPROACHES TO BREATHING PAlTERN DISORDERS

Volumes Capacities 6000

5000

4000

2000

1000

0 Time + Figure 1.14 Lung volumes and capacities as displayed by a time versus volume spirogram. Values are approximate. The tidal volume is measured under resting conditions. (Reproduced from Beachey 1998.) attaching ribs, together with their anterior sternal observations below. These notes discuss the connections and all the soft tissues, muscles, liga- fascia, the joints of the thoracic cage - including ments, tendons, and fascia, need to be structurally spinal and rib structures - and the musculature intact, with an uncompromised neural supply. and other soft tissues of the region. Functional Without an efficient pump mechanism all other influences on these structures (e.g. gait and respiratory functions will be suboptimal. Clearly, posture) are evaluated insofar as they impact on a host of dysfunctional patterns can result from the efficiency of the respiratory process. altered airway characteristics, abnormal status of the lungs, and/or from emotional and other influences. However, even if allergy or infection FASCIA AND RESPIRATORY is causal in altering the breathing pattern, the FUN CTl ON process of breathing can be enhanced by rela- Page (1952) describes the fascia1 linkage as tively unglamorous nuts-and-bolts features such follows: as the normalization of rib restrictions or short- ened upper fixator muscles (see Ch. 6 for further The cervical fascia extends from the base of the skull to the mediastinum and forms compartments discussion). enclosing oesophagus, trachea, carotid vessels and The major structural components of the provides support for the pharynx, larynx and process of breathing are briefly outlined in the thyroid gland. There is direct continuity of fascia THE STRUCTURE AND FUNCTION OF BREATHING 21

from the apex of the diaphragm to the base of the on the right and two on the left, wrapped in a skull. Extending through the fibrous pericardium membranous fascial structure, the pleura, upward through the deep cervical fascia and the which separates the lungs from the inner tho- continuity extends not only to the outer surface of the sphenoid, occipital and temporal bones but racic wall, and attaches to the thoracic struc- proceeds further through the foramina in the base tures superiorly at the hilum and inferiorly to of the skull around the vessels and nerves to join the diaphragm. Barrell highlights the impor- the dura. tance of this connection: ’The pleura is prob- An obvious corollary to this vivid descrip- ably the structure most affected by the tion of the continuity of the fascia is that dis- twenty-four thousand daily diaphragmatic tortion or stress affecting any one part of the movements, particularly in its superior attach- structure will have repercussions on other ments.’ (Ideally, breathing rates are between parts of the same structure. For example, if 10 and 14 per minute; therefore, the normal 24- the position of the cervical spine in relation to hour total would range from 14 000 to 20 000.) the thorax alters (as in a habitual forward- The suspensory attachment of the pleura (and head position), or if the position of the pericardium), to the skeleton, is via a connec- diaphragm alters relative to its normal posi- tive tissue dome comprising a variety of tion (as in a slumped posture), the functional myofascial tissues and ligaments which attach efficiency of the breathing mechanisms may to the spine and deep cervical aponeurosis be compromised. close to the cervicothoracic junction. Barrell (1991) points out that while the mobile pleura 0 Rolfer Tom Myers (1997) has described what require a point of stability, ’it is somewhat he terms the ‘deep front line’ - fascial con- paradoxical that the cervical spine is much nections linking the osseous and soft tissue more mobile than the thorax, but at the same structures which highlight clearly how modi- time serves as a superior fixed point for the fications in posture involving spinal and/or pleural system.’ Barrell observes that on dis- other attachment structures will directly section of degenerated lower cervical struc- modify the fascia which envelops, supports, tures it is common to find associated excessive and gives coherence to the soft tissues of the thickening and fibrotic change to the pleu- breathing mechanism: ropulmonary attachments: ’in view of the rela- -the anterior longitudinal ligament, tionships between the pleural attachments and diaphragm, pericardium, mediastinum, neurovascular system, it is easy to imagine the parietal pleura, fascia prevertebralis and disorders which can arise in this strategic area, the scalene fascia connect the lumbar spine and their effects on nearby organs.’ (bodies and transverse processes) to the cervical transverse processes and via In considering function and dysfunction of the longus capitis to the basilar portion of the respiratory system, fascial continuity should be occiput kept in mind, since evidence of a local dysfunc- -other links in this chain involve a connec- tional state (say of a particular muscle, spinal tion between the posterior manubrium and segment, rib, or group of ribs) can be seen to be the hyoid bone, via the subhyoid muscles capable of influencing (and being influenced by) and the fascia pretrachealis, between the distant parts of the same mechanism, as well as hyoid and the cranium/mandible, involv- other areas of the body, via identifiable fascial ing the suprahyoid muscle as well as the connections. muscles of the jaw linking the mandible to the face and cranium. THORACIC SPINE AND RIBS 0 Barral (1991) details additional fascial features of the respiratory mechanism, pointing out The posterior aspect of the thorax is represented that there are five lung lobes (segments),three by a mobile functional unit, the thoracic spinal 22 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS column, through which the sympathetic nerve infrequent occurrence. Degenerative changes supply emerges: due to osteoporosis and aging, as well as trauma, are relatively common in this region and may 0 The degree of movement in all directions impact directly on respiratory function as a result (flexion, extension, sideflexion, and rotation) of restricted mobility of the thoracic structures. allowed by the relatively rigid structure of the thorax is less than that available in the cervical or lumbar spines, being deliberately limited in Structural features of the ribs order to protect the vital organs housed within (see Fig. 1.9, above) the thoracic cavity. 0 In most individuals the thoracic spine has a The ribs are composed of a segment of bone and kyphotic (forward-bending) profile which a costal cartilage. The costal cartilages attach to varies in degree from individual to individual. the costochondral joint of most ribs (see varia- 0 The thoracic spinous processes are especially tions below), depressions in the bony segment of prominent, and therefore easily palpated. the ribs. Ribs 11 and 12 do not articulate with the 0 The transverse processes from T1 to T10 carry costotransverse joints for articulation with sternum ('floating ribs'), whereas all other ribs do the ribs. so, in various ways, either by means of their own cartilaginous synovial joints (i.e. ribs 1-7, which The thoracic facet joints, which glide on each are 'true ribs') or by means of a merged cartilagi- other and restrict and largely determine the range nous structure (ribs 8-10, which are 'false ribs'). of spinal movement, have typical plane-type The head of each rib articulates with its thoracic synovial features, including an articular capsule. vertebrae at the costovertebral joint. Ribs 2-9 also articulate with the vertebrae above and below by Facet orientation means of a demifacet. Ribs 1, 11, and 12 articulate with their own vertebrae by means of a unifacet. Hruby and colleagues (1997) describe a useful Typical ribs (3-9) comprise a head, neck, method for remembering the structure and ori- tubercle, angles, and shafts and connect directly, entation of the facet joints (of particular value or via cartilaginous structures, to the sternum. when using mobilization methods, see Ch. 6): The posterior rib articulations allow rotation The superior facets of each thoracic vertebrae are during breathing, while the anterior cartilagi- slightly convex and face posteriorly (backward), nous elements store the torsional energy pro- somewhat superiorly (up), and laterally. Their angle duced by this rotation. The ribs behave like of declination averages 60" relative to the transverse tension rods and elastically recoil to their previ- plane and 20" relative to the coronal plane. Remember the facet facing by the mnemonic. 'BUL' (backward, ous position when the muscles relax. These upward, and lateral). This is in contrast to the cervical elastic elements reduce with age and may also be and lumbar regions where the superior facets face lessened by intercostal muscular tension. backwards, upwards, and medially ('BUM'). Thus, Rib articulations, thoracic vertebral positions, the superior facets [of the entire spine] are BUM, BUL, and myofascial elements must all be functional BUM, from cervical, to thoracic to lumbar. for normal breathing to occur. Dysfunctional ele- ments may reduce the range of mobility, and, Discs therefore, lung capacity. The disc structure of the thoracic spine is similar to that of the cervical and lumbar spine. The Atypical ribs notable difference is the relative broadness of the Atypical ribs and their key features include: posterior longitudinal ligament which, together with the restricted range of motion potential of 0 Rib 1, which is broad, short and flat, is the the region, makes herniation of thoracic discs an most curved. The subclavian artery and cervi- THE STRUCTURE AND FUNCTION OF BREATHING 29

cal plexus are anatomically vulnerable to com- Structural features of the sternum pression if the 1st rib becomes compromised (see Fig. 1.9, above) in relation to the anterior and/or middle scalenes, or the clavicle. There are three key subdivisions of the sternum: 0 Rib 2 carries a tubercle which attaches to the 1. The manubrium (or head) which articulates proximal portion of serratus anterior. with the clavicles at the sternoclavicular joints. 0 Ribs 11 and 12 are atypical due to their failure The superior surface of the manubrium (jugular to articulate anteriorly with the sternum or notch) lies directly anterior to the 2nd thoracic costal cartilages. vertebra. The manubrium is joined to the body of the sternum by means of a fibrocartilaginous Rib dysfunction and appropriate treatments symphysis, the sternal angle (angle of Louis), are discussed in Chapter 6. which lies directly anterior to the 4th thoracic vertebra (Fig. 1.15). 2. The body of the sternum provides the attach- Intercostal musculature ment sites for the ribs, with the 2nd rib attaching at the sternal angle. This makes the angle an Stone (1999) amplifies the generally understood important landmark when counting ribs. role of the intercostal muscles and their func- 3. The xyphoid process is the 'tail' of the tions: 'For many years the intercostals were sternum, joining it at the xyphisternal symphysis attributed with a very complex biomechanical (which fuses in most people during the fifth effect, such that the internal intercostals were decade of life), usually anterior to the 9th tho- considered expiratory muscles and the external racic vertebra. intercostals inspiratory muscles' (Kapandji 1974). Stone continues by explaining that the processes Posterior thorax involved are far more complicated and that they relate to air and fluid movement within the tho- In regional terms, the thoracic spine is usually racic cavity: 'During inspiration and expiration divided into (White & Panjabi 1978): upper there are cascades of action within the intercostal (T14), middle (T5-8), lower (T9-12): muscles, which start at one end of the rib cage The total range of thoracic flexion and and progress to the other to produce the required extension combined (between T1 and T12) is changes in rib cage shape.' approximately 60" (Liebenson 1996) De Troyer & Estenne (1988) showed that The total range of thoracic rotation is during inhalation the external intercostals are approximately 40" activated from superior to inferior, while during Total range of lateral flexion of the thoracic forced exhalation the internal intercostals are spine is approximately 50". activated from inferior to superior. The implica- tion is that, on inhalation, stabilization of the Palpation landmarks upper ribs is required, involving scalenes (De Troyer 1994) to allow the sequential intercostal A useful way of identifying the thoracic verte- contraction wave to progress inferiorly. In con- brae involves the so-called 'rule of threes'. This trast, during forced exhalation the lower ribs 'rule' is simply an approximate generalization, require stabilization - by quadratus lumborum but it positions the palpating fingers in the esti- mated positions for locating individual thoracic - to allow the superiorly directed wave to occur. Muscular imbalances (shortness, weakness, etc.) vertebrae (Hruby et a1 1997): could therefore inpact on normal breathing The spinous processes of T1-3 project directly function. (Assessment and treatment of mus- posteriorly so that the tip of each spinous cular imbalances are discussed in Chapters 6 process is in the same plane as the transverse and 7.) process of the same vertebra 24 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

Figure 1.15 Manubrium sternum. (Reproduced with kind permission from Gray 1995.)

The spinous processes of T4-6 project Box 1.2 describes some research into respiratory caudally so that the tip of each spinous synkinesis and Box 1.3 describes the segmental process is in a plane that is approximately coupling that takes place during compound halfway between the transverse processes of spinal movements. its own vertebra and those of the vertebra immediately below The spinous processes of T7-9 project more NEURAL REGULATION OF acutely caudally so that the tip of each spinous BREATHING process is in the same plane as the transverse processes of the vertebra immediately below Respiratory centres in the most primitive part of T10 spinous process is similar to T7-9 (same the brain, the brainstem, unconsciously influ- plane as the transverse processes of the ence and adjust alveolar ventilation to maintain vertebra immediately below) arterial blood oxygen and carbon dioxide pres- T11 spinous process is similar to T4-6 (in a sures (Pco,)at relatively constant levels in order plane that is approximately halfway between to sustain life under varying conditions and the transverse processes of its own vertebra requirements. and those of the vertebra immediately below) There are three main groups: T12 spinous process is similar to T1-3 (in the same plane as the transverse process of the 1. The dorsal respiratory group is located in the same vertebra). distal portion of the medulla. It receives input THE STRUCTURE AND FUNCTION OF BREATHING 25

Box 1.2 Respiratory synkinesis pharyngeal nerves. These impulses generate inspiratory movements and are responsible Numerous adaptive combinations are possible in the for the basic rhythm of breathing. thoracic spine, partly as a result of the compound influences and potentials of the muscles attaching to 2. The pneumotaxic centre in the superior part each segment. There seems to be a potential for of the pons transmits inhibitory signals to the compensatory patterning at all thoracic spinal levels. dorsal respiratory centre, controlling the Lewit (1999) describes some research by Gaymans (1980) into respiratory synkinesis. This explains the filling phase of breathing. apparent alternating inhibitory and mobilizing effects on 3. The ventral respiratory group, located in the spinal segments during inhalation and exhalation which medulla, causes either inspiration or expira- appear to follow a predictable pattern in the cervical and thoracic spine during side-flexion. For example: tion. It is inactive in quiet breathing but is On inhalation, resistance increases to side-flexion in important in stimulating abdominal expira- the even segments (occiput-atlas, C2 etc. T2, T4, tory muscles during levels of high respira- etc.) while in the odd segments there is a mobilizing tory demand. effect (i.e. they are more free) On exhalation, resistance increases to side-flexion in The Hering-Breuer reflex prevents overinflation the odd segments (C1 , C3, etc., T3, T5, etc.) while of the lungs and is initiated by nerve receptors in in the even segments there is a mobilizing effect (i.e. they are more free) the walls of the bronchi and bronchioles sending The area involving C7 and T1 seems ‘neutral’ and messages to the dorsal respiratory centre, via the uninvolved in this phenomenon At the cervicocranialjunction, the restrictive and vagus nerves. It ’switches off excessive inflation mobilizing effects to inhalation and exhalation during inspiration, and also excessive deflation respectively seem to involve not just side-bending during exhalation. but all directions of motion The ‘mobilizing influences’ of inhalation as described above, diminish in the lower thoracic region. Chemical control of breathing The clinical value of this knowledge would be apparent during mobilization of segments in which side-flexion is The central role of respiration is to maintain bal- a component of the restriction. In the thoracic region in anced concentrations of oxygen (02)and carbon particular there would be value in encouraging the dioxide (COJ in the tissues. Increased levels of appropriate phase of respiration when applying specific segmental mobilization techniques. C02 act on the central chemosensitive areas of the respiratory centres themselves, increasing inspiratory and expiratory signals to the respira- tory muscles. 0, on the other hand, acts on Box 1.3 Segmental coupling peripheral chemoreceptors located in the carotid Biomechanical coupling of segments occurs during body (in the bifurcation of the common carotid compound movements of the spine. During side-flexion arteries) via the glossopharyngeal nerves, and an automatic rotation occurs due to the planes of the facets. In the thoracic spine this coupling process is the aortic body (on the aortic arch) which sends less predictable than in the cervical region, where from the appropriate messages via the vagus nerves to C3 downwards type 2 coupling (also known as ‘non- the dorsal respiratory centre. neutral’) is the norm (i.e. side-bending and rotation occur to the same side). Voluntary control of breathing Hruby and colleagues (1997) state: I Upper thoracic coupling is typically neutralhype 2 [i.e. side- Automatic breathing can be overridden by bending and rotation take place towards the same side] and generally occurs as low as T4 ... [whereas] ... middle thoracic higher cortical conscious input (directly, via the coupling is commonly a mix of neutralhype 1 and non- spinal neurons which drive the respiratory neutralhype 2 movements, that may rotate to either the formed convexity [type I]or concavity [type 21. Lower thoracic coupling muscles) in response to, for instance, fear or is more apt to accompany lumbar neutralhype 1 mechanics. sudden surprise. Speaking requires voluntary control to interrupt the normal rhythmicity of breathing, as does singing and playing a wind from peripheral chemoreceptors and other instrument. There is evidence that the cerebral types of receptors via the vagus and glosso- cortex and thalamus also supply part of the drive 28 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS for normal respiratory rhythm during wakeful- system is also concerned with the emptying of the ness (cerebral influences on the medullary bladder and with sexual activity. centres are withdrawn during sleep). Breathing Innervation of smooth muscle in the walls of pattern disorders (BPDs) and hyperventilation the arterioles varies their caliber, permitting the syndromes (HVSs) probably originate from some maintenance of blood pressure and the switching of these higher centres (Timmons 1994, p. 35). up and down of various parts of the circulation according to whether digestion, growth and repair, heat conservation or loss, or strong mus- THE AUTONOMIC NERVOUS SYSTEM cular activity are required. The maintenance of an adequate circulation also depends on the (Table 1.1) heart rate, the strength of the cardiac muscle con- This system enables the automatic unconscious traction thereby varying the cardiac output. maintenance of the internal environment of the The hypothalamus in the brainstem has a key body in ideal efficiency, and adjusts to the various role in coordinating the diverse functions of the demands of the external environment, be it sleep autonomic nervous system, as well as controlling with repair and growth, quiet, or extreme physi- the release of hormones from the pituitary gland, cal activity and stress. The nerves innervate the to which it is connected by a stalk carrying smooth muscle of the alimentary canal causing the releasing factors. Some pituitary hormones propulsion of food, while the nerves to exocrine directly control the biochemical processes of the glands initiate secretion of digestive juices. The body. On the other hand, the pituitary trophic hor-

Table 1.1 Comparison of the autonomic and somatic motor nervous systems (from Beachey 1998)

Features Somatic motor nervous system Autonomic nervous system

Target tissues Skeletal muscle Smooth muscle, cardiac muscle, and glands Regulation Control of all conscious and unconscious Unconscious regulation, although influenced movements of skeletal muscle by conscious mental functions Response to stimulation Skeletal muscle contracts Target tissues are stimulated or inhibited Neuron arrangement One neuron extends from the central Two neurons in series; the preganglionic neuron nervous system (CNS) to skeletal extends from the CNS to an autonomic muscle ganglion, and the postganglionic neuron extends from the autonomic ganglion to the target tissue Neuron cell body location Neuron cell bodies are in motor nuclei Preganglionic neuron cell bodies are in autonomic of the cranial nerves and in the nuclei of the cranial nerves and in the ventral horn of the spinal cord lateral horn of the spinal cord; postganglionic neuron cell bodies are in autonomic ganglia Number of synapses One synapse between the somatic Two synapses; first in the autonomic ganglia, motor neuron and the skeletal second at the target tissue muscle Axon sheaths Myelinated Preganglionic axons myelinated, postganglionic axons unmyelinated Neurotransmitter substance Acetylcholine Acetylcholine released by preganglionic neurons; either acetylcholine or norepinephrine released by postganglionic neurons Receptor molecules Receptor molecules for acetylcholine In autonomic ganglia, receptor molecules for are nicotinic acetylcholine are nicotinic; in target tissues, receptor molecules for acetylcholine are muscarinic, whereas receptor molecules for norepinephrine are either a- or P-adrenergic THE STaUCVWRE &lW FUNCTION OF BREATHING 27 mones control the activity of target endocrine chain, where they synapse with postgan- glands, such as the thyroid and adrenals, in secret- glionic neurons. These in turn send fibers ing their own hormones, which in turn control along the arteries to autonomic effectors, be other metabolic processes. The hypothalamus has they glands or smooth muscle. connections with the preganglionic neurons The sympathetic ganglion chain has at its upper further down the brainstem and the spinal cord. end the superior, middle, and stellate ganglia, The system has a set of receptors from which housing the postganglionic neurons which afferent nerve fibers carry impulses to the central supply effectors in the head, neck, and heart. nervous system for integration and action. This 0 The outflow from thoracic segments 1-4 sup- action is mediated by impulses transmitted plies the larynx, trachea, bronchi, and lungs, down a set of efferent nerves to effector organs while thoracic segments 5-12 fire the greater which are mainly smooth muscles and glands. and small splanchnic nerves, enter the celiac Besides the afferent and efferent pathways, there and superior mesenteric ganglia. The inferior are two divisions: mesenteric ganglion is supplied by lumbar segments Nerve fibers from these three The sympathetic, mainly concerned with 1-3,4. ganglia supply the organs in the abdomen and preparing the body for, and handling the genitalia. stressful situations, adapting to the needs of the external environment The parasympathetic, serving visceral Parasympathetic division (Tables 1.2 and functions such as digestion, absorption, and 1.3; Fig. 1.16) growth (see Tables 1.2 and 1.3). 0 The parasympathetic outflow occurs in two regions: cranial with the preganglionic axons Sympathetic division (Tables 1.2 and 1.3; traveling in the oculomotor, facial, glosso- Figs. 1.16,1.17) pharyngeal, and vagus nerves to ganglia situ- 0 The sympathetic outflow from preganglionic ated close to the effector mechanisms; the neurons in the spinal cord is carried by way of sacral outflow supplies the pelvic organs their axons through the ventral routes of the through the second to fourth sacral nerves first thoracic, all the way down to the third or coming together as the pelvic nerve. fourth lumbar spinal nerves, some 15-16 pairs. 0 The lungs are entirely governed by autonomic They make up the white rami communicantes sensory and motor nerves: there is no voluntary to the paravertebral sympathetic ganglionic motor control over airway smooth muscles.

Table 1.2 Comparison of the sympathetic and parasympathetic divisions (from Beachey 1998)

Feature Sympathetic division Parasympathetic dlvislon

Location of preganglionic cell body Lateral horns of spinal cord gray matter Brainstem and lateral horns of spinal cord (Ti-L2) gray matter (S244) Outflow from central nervous Spinal nerves Cranial nerves system Sympathetic nerves Pelvic nerves Splanchnic nerves Ganglia Sympathetic chain ganglia along spinal Terminal ganglia near or on effector organ cord for spinal and sympathetic nerves; collateral ganglia for splanchnic nerves Number of postganglionic neurons Many Few for each preganglionic neuron Relative length of neurons Short preganglionic Long preganglionic Long postganglionic Short postganglionic 28 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

Table 1.3 Comparison of the sympathetic and parasympathetic divisions (from Beachey 1998)

Organ Effect of sympathetlc stlmulation Effect of parasympathetic stimulation

Heart Muscle Increased rate and force (b) Slowed rate (c) Coronary arteries Dilated (b), constricted (a)' Dilated (c) Systemic blood vessels Abdominal Constricted (a) None Skin Constricted (a) None Muscle Dilated (b), constricted (a) None Lungs Bronchi Dilated (b) Constricted (c) Liver Glucose released into blood (b) None Skeletal muscles Breakdown of glycogen to glucose (b) None Metabolism Increased up to 100% (a, b) None Glands Adrenal Release of epinephrine and norepinephrine None (4 Salivary Constriction of blood vessels and slight production Dilation of blood vessels and thin, copious of a thick, viscous secretion (a) secretion (c) Gastric Inhibition (a) Stimulation (c) Pancreas Decreased insulin secretion (a) Increased insulin secretion (c) Lacrimal None Secretion (c) Sweat Merocrine Copious, watery secretion (c) None Apocrine Thick, organic secretion (c) None Gut Wall Decreased tone (b) Increased motility (c) Sphincter Increased tone (a) Decreased tone (c) Gallbladder and bile ducts Relaxed (b) Contracted (c) Urinary bladder Wall Relaxed (b) Contracted (c) Sphicter Contracted (a) Relaxed (c) Eye Ciliary muscle Relaxed for far vision (b) Contracted for near vision (c) Pupil Dilated (a) Constricted (c) Errector pili muscles Contraction (a) None Blood Increased coagulation (a) None Sex organs Ejaculation (a) Erection (c) a Mediated by a-adrenergic receptors; b, mediated by P-adrenergic receptors; c, mediated by cholinergic receptors. 'Sympathetic stimulation of the heart normally increases coronary artery blood flow because of increased cardiac muscle demand for oxygen.

0 A further subdivision of the autonomic 0 NANC inhibitory nerves cause calcium ions nervous system is on the basis of the chemical to enter the neuron, mediating smooth transmission across the synapses. muscle relaxation and bronchodilation 0 NANC stimulatory fibers - also called C-fibers - are found in the lung supporting NANC system tissue, airways, and pulmonary blood vessels, and appear to be involved in Researches have recognized a 'third' nervous bronchoconstriction following cold air system regulating the airways called the non- breathing and in exercise-induced asthma adrenergic noncholinergic (NANC) system, con- (Beachey 1998, p. 30). taining inhibitory and stimulatory fibers; nitric oxide (NO) has been identified as the NANC Box 1.4 gives an example of autonomic res- neurotransmitter (Snyder 1992). ponses following stress/distress. THE STRUCTURE AND FUNCTION OF BREATHING 29

...... -.... Parasympathetic -Sympathetic _---- Motor (to skeletal muscle)

Figure 1.16 Schema of the autonomic innervation (motor and sensory) of the lung and the somatic (motor) nerve supply to the intercostal muscles and diaphragm. (Reproduced from Scanlan et al 1995.)

Box 1.4 An example of autonomic responses

A patient has become alarmed at the sight of blood and normal blood pressure is restored and blood flow to the the pain from a wound. The immediate reaction to this brain and brainstem increases, thereby preventing a faint. stress is a strong vagal response, slowing the heart rate. Moreover, there is a discharge in the adrenal medulla As blood flow slows down in the vertebral arteries releasing epinephrine and norepinephrine which cause a supplying the brainstem, a feeling of nausea and further increase in heart rate and narrowing of the faintness supervenes. Pressor receptors in the carotid arterioles. These receptors allow the development and arteries sense the fall in blood pressure and its threat to use of drugs that either stimulate certain receptors the cerebral circulation. From the receptors, impulses (agonists) or block some receptors (antagonists or travel up the afferents in the glossopharyngeal nerves to blockers). For example, beta-blockersare used in the the cardiorespiratorycenter in the medulla. This in turn control of hypertension, favoring the dilation of arterioles sends a cascade of efferent impulses down the spinal and slowing of the heart. A number of beta agonists are cord and out along the thoracic spinal nerves. The useful in asthma, relaxing the bronchospasm of the sympathetic and adrenergic outflow speeds up the heart bronchial musculature set up by allergic responses or and constricts the blood vessels of the body. In this way, infection. 30 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

placement in space of the shoulders, arms, neck, THE MUSCLES OF RESPIRATION and head. The intrinsic thoracic muscles move the thoracic vertebrae or the rib cage (and poss- The extrinsic thoracic musculature is responsible ibly the entire upper body) and/or are associated for positioning the torso, and therefore, also the with respiration. THE STFtUCTURE AND FUNCTION OF BREATHING 31

The deeper elements of the thoracic muscula- mental stability, particularly transversus abdo- ture represent a remarkable system by means of minis (Hodges 1999). The rectus abdominis, which respiration occurs. Some of these muscles external and internal obliques and transversus also provide rotational components which carry abdominis are also involved in respiration due similar, spiraling, lines of oblique tension from to their role in positioning the abdominal viscera the pelvis (external and internal obliques) as well as depression of the lower ribs, assisting through the entire torso (external and internal in forced expiration (especially coughing). intercostals), almost as if the ribs were 'slipped into' this supportive web of continuous muscu- Additional soft tissue influences and lar tubes. Rolfer Tom Myers (1997) describes the connections physical continuity which occurs between these muscles (obliques and intercostals). Above the 0 The soft tissue links between the thoracic pelvic crest this myofascial network creates a region and the pelvic region include major series of crossover (X-shaped) patterns: structures such as quadratus lumborum, transversus abdominis, and psoas, which The obliques tuck into the lower edges of the basket merge with the diaphragm and therefore have of ribs. Between each of the ribs are the internal and external intercostals, which taken all together form a the potential to influence breathing function. continuation of the same 'X', formed by the obliques. 0 The internal and external obliques (usually These muscles, commonly taken to be accessory described as trunk rotators) also merge with muscles of breathing, are seen in this context to be the diaphragm and lower ribs and can have perhaps more involved in locomotion [and stability], marked influences on respiratory function. It helping to guide and check the torque, swinging through the rib cage during walking and running. is worth reflecting that this works in reverse, (Myers 1997) and that diaphragmatic and respiratory dys- function is bound to affect these associated Richardson and colleagues (1999) describe muscles. research into the behaviour of the abdominal 0 The primary inspiratory muscles are the muscles during quiet breathing. They found that diaphragm, the more lateral external inter- the abdominal musculature was activated costals, parasternal internal intercostals, towards the end of exhalation, and noted that scalene group, and levatores costarum, with 'Contraction of the abdominal muscles con- the diaphragm providing 70-80% of the tributes towards the regulation of the length of inhalation force (Simons et a1 1998). the diaphragm, end-expiratory lung volume and 0 These muscles are supported, or their role is expiratory airflow'. replaced, by the accessory muscles during With a voluntary increase in exhalation force, increased demand (or dysfunctional breath- all the muscles of the abdomen contract simulta- ing patterns): sternocleidomastoid (SCM), neously. However, when increased exhalation upper trapezius, pectoralis major and minor, force occurs involuntarily, transversus abdo- serratus anterior, latissimus dorsi, serratus minis is recruited before the other abdominal posterior superior, iliocostalis thoracis, sub- muscles (rectus abdominis, obliquus externus clavius, and omohyoid (Kapandji 1974, abdominis), producing enhancement of inspira- Simons et a1 1998). tory efficiency by increasing the diaphragm's length and permitting an elastic recoil of the INSPIRATORY AND EXPIRATORY thoracic cavity. MUSCLES (Box 1.5) Like the erector system of the posterior thorax, the abdominal musculature plays a significant The muscles associated with breathing function role in positioning the thorax and in rotating the can be grouped as either inspiratory or expiratory, entire upper body. It is also now known to play and are either primary in that capacity or provide a key part in spinal stabilization and interseg- accessory support. It should be kept in mind that 32 MULTIDISCIPLINARY APPROACHES TO BREATHING PAlTERN DISORDERS

Box 1.5 Muscles of breathing singing, and other special functions associated with the breath. In addition: Muscles of inhalation 0 The intercostal muscles, while participating in Primary Diaphragm inhalation (external intercostals) and exhala- Parasternal (intercartilaginous) internal intercostals tion (internal intercostals), are also respons- Upper and more lateral external intercostals ible for enhancing the stability of the chest Levatores costarum Scalenes wall, so preventing its inward movement during inspiration. Accessory 0 Quadratus lumborum (QL) acts to fix the 12th Sternocleidomastoid Upper trapezius rib, so offering a firm attachment for the Serratus anterior (arms elevated) diaphragm. If QL is weak, as it may be in certain Latissimus dorsi (arms elevated) individuals, this stability is lost (Norris 1999). Serratus posterior superior lliocostalis thoracis 0 Bronchial obstruction, pleural inflammation, Subclavius liver or intestinal encroachment and ensuing Omohyoid pressure against the diaphragm, as well as Muscles of exhalation phrenic nerve paralysis are some of the Primary pathologies which will interfere with diaphrag- Elastic recoil of lungs, diaphragm, pleura and costal matic and respiratory efficiency. cartilages Box 1.6 describes some muscle characterization Accessory models and the dual roles of some specific lnterosseous internal intercostals Abdominal muscles muscles. Transversus thoracis Su bcostales lliocostalis lumborum GAIT INFLUENCES Quadratus lumborum Serratus posterior inferior The major postural muscles of the body (anterior Latissimus dorsi and posterior aspects) are shown in Figure 1.18A and B. Gait involves the spine in general, and the thoracic spinal muscles in particular, and by the role that these muscles might play in inhibit- inference can impact on respiratory function. ing respiratory function (due to trigger points, Gracovetsky (1997) reports: ’In walking, the hip ischemia, etc.) has not yet been clearly established, extensors fire as the toe pushes the ground. The and that their overload, due to dysfunctional muscle power is directly transmitted to the spine breathing patterns, is likely to impact on cervical, and trunk via two distinct but complementary shoulder, lower back, and other body regions. pathways’: Box 1.5 lists the muscles of breathing, both 0 Biceps femoris has its gait action extended by inspiratory and expiratory. the sacrotuberous ligament, which crosses the Since expiration is primarily an elastic response superior iliac crest and continues upward as of the lungs, pleura, and ‘torsion rod’ elements of the erector spinae aponeurosis, iliocostalis the ribs, all muscles of expiration could be consid- lumborum, and iliocostalis thoracis (among ered to be accessory muscles as they are recruited others), and linking directly with the contra- only during increased demand. They include lateral latissimus dorsi. internal intercostals, abdominal muscles trans- 0 Gluteus maximus force is transmitted super- versus thoracis, and subcostales. With increased iorly via the lumbodorsal fascia and latis- demand, iliocostalis lumborum, quadratus lum- simus dorsi borum, serratus posterior inferior, and latissimus dorsi may support expiration, including during In this way, an oblique muscle-tendon-fascia1 the high demands of speech, coughing, sneezing, sling is created across the torso, providing a THE STRUCTURE AND FUNCTION OF BREATHING 33

Box 1.6 Muscle characterizations(see also Box 4.1)

Richardson and colleagues (1999) have categorized Interestinglythe dysfunctional pattern seems to have less muscles capable of controlling one joint or one area of the to do with strength or endurance capabilities than with spine as being ‘rnonoarticular‘.These could also be motor control. Since the muscle acts to stabilize the spine, referred to as ‘local’ muscles. They also describe dysfunction is bound to contribute to spinal imbalance; ‘multijoint’ muscles which are capable of moving several however, the impact on respiration is less clear. joints at the same time. These muscles are also Richardson and colleagues also highlight the phylogenetically the oldest. They can be referred to as importance, in postural control, of the diaphragm. In a ‘global’ muscles. This nomenclature allows clinical study which measured activity of both the costal disciplines to communicate with other basic science diaphragm and the crural portion of the diaphragm, as disciplines in order to facilitate research and learning. well as transversus abdominis, it was found that Other muscle categorization models include ’postural/ contraction occurred in all these structures when spinal phasic’ (Janda 1983), and ‘mobilizer/stabilizer’(Norris stabilization was required (in this instance during shoulder 1999). There are relative advantages in being able to flexion). ‘The results provide evidence that the diaphragm describe and see the way the body works using these does contribute to spinal control and may do so by models. assisting with pressurization and control of displacement of the abdominal contents, allowing transversus Dual roles of specific muscles abdominus to increase tension in the thoracolumbar Research shows that many of the muscles supporting and fascia or to generate intra-abdominal pressure.’ The moving the thorax and/or the spinal segments (including involvement of the diaphragm in postural stabilization erector spinae) prepare to accommodate for subsequent suggests that situations might easily occur where such movement as soon as arm or shoulder activity is initiated, contradictory demands are evident, where postural with deep stabilizing activity from transversus abdominis, stabilizing control is required at the same time that for example, occurring miniseconds before unilateral rapid physiological requirements create demands for greater arm activity (Hodges & Richardson 1997). Stabilization of diaphragmatic movement: ‘This is an area of ongoing the lumbar spine and thorax has been shown to depend, research, but must involve eccentric/concentric phases of to a large extent, on abdominal muscle activity (Hodges activation of the diaphragm’ (Richardson et al 1999). 1999). Transversus abdominis is categorized as a local, Just what the impact is on respiratory function of stabilizing structure. Richardson and colleagues (1999) transversus abdominis and of the diaphragm when dual note that the direct involvement of this muscle in stabilizing and respiratory roles occur is an open respiration -where it contributes to forced exhalation - question; the impact would doubtless be strongly leads to a potential conflict with its role as a spinal influenced by the relative fitness and health of the stabilizer. They have identified a clear linkage between individual. dysfunction of transversus abdominis and low back pain.

mechanism for energy storage, to be utilized in column or cage, as well as respiratory function. the next phase of the gait cycle. As Lee (1997) Though many of these muscles have very short points out: ’Together, these two muscles [gluteus fibers, and therefore may appear relatively unim- maximus and latissimus dorsil tense the thora- portant, they are strategically placed to provide, codorsal fascia and facilitate the force closure or initiate, precisely directed movement of the mechanism through the sacro-iliac joint.’ thoracic vertebrae and/or ribs. They therefore Gracovetsky (1997) continues: ’As a conse- demand due attention in evaluation of restric- quence, firing hip extensors extends and raises tions within these structures. the trunk in the sagittal plane. The chemical energy liberated within the muscles is now con- verted by the rising trunk, into potential energy UPPER THORACIC MUSCLES (see Fig. 1.18A and stored in the gravitational field. When a person is B) running, so much energy needs to be stored that When viewing the posterior thorax, the trapezius the necessary rise in the centre of gravity forces is immediately obvious as it lies superficially and the runner to become airborne.’ extensively covers the upper back, shoulder and The intrinsic thoracic muscles are largely neck. In addition to trapezius, latissimus dorsi, responsible for movement of the thoracic spinal which superficially covers the lower back, as well 34 MULTDlSCtPUNARY APPROACHES TO BREATHINO PATERN DISORDERS -

Flgum 1.18 A The major postural muscles of the anterior aspect of the W.B The major postural muscles of the posterior aspect of the My.{Reproduced with kind permission from Chaitow 1ssSC.)

as the rhomboids, serratus anterior, and pec- inferior borders of the angles of the lower 6-9 toralis major and minor, are of possible clinical ribs. significance in breathing imbalance. A complex lliocostalis thoracis fibers run from the super- array of short and long extensors and rotators ior borders of the lower 6 ribs to the upper 6 lies deep to the more superficial trapezius, latis- ribs and the transverse process of C7. simus dorsi, and rhomboids. Platzer (1992) Longissimus thoracis shares a broad thick breaks these two groups into lateral (superficial) tendon with ilimostalis lumborum, and fiber and medial (deep) tracts, each having a vertical attachments to the transverse and accessory (intertransverse)and diagonal (transversospinal) processes of the lumbar vertebrae and thora- component. This subdivision offers a useful columbar fascia, which then attaches to the mdewhen assessing rotational dysfunctions, as tips of the transverse processes and between the superficial rotators are synergistic with the the tubercles and angles of the lower 9-10 ribs. contralateral deep rotators. The thoracic component of the erector spinae system has numerous attachments onto the ribs. Thoracic musculature 0 Trigger points in these vertical muscular columns refer caudally and cranially across a Iliocostalis lurnborum extends from the iliac the thorax and lumbar regions, into the gluteal crest, sacrum, thoracolumbar fascia, and region, and anteriorly into the chest and spinous processes of T11-W to attach to the abdomen. THE STRUCTURE AND FUNCTION OF BREATHING 35

Multifidi NOTES ON SPECIFIC MUSCLES Attachments. From the posterior surface of the sacrum, iliac crest, and the transverse processes Spinalis thoracis of all lumbar, thoracic vertebrae and articular Attachments. Spinous processes of Tll-L2 to the processes of cervicals 4-7, these muscles tra- spinous processes of T4-T8 (variable). verse 2-4 vertebrae and attach superiorly to the Innervation. Dorsal rami of spinal nerves. spinous processes of all vertebrae apart from Function. Acting unilaterally, flexes the spine the atlas. laterally; bilaterally, extends the spine. Innervation. Dorsal rami of spinal nerves. Synergists. For lateral flexion: ipsilateral semi- Function. When these contract unilaterally they spinalis, longissimus and iliocostalis thoracis, produce ipsilateral flexion and contralateral iliocostalis lumborum, quadratus lumborum, rotation; bilaterally, they extend the spine. obliques, and psoas. Synergists. For rotation: multifidi, semispinalis Antagonists. To lateral flexion: contralateral semi- muscles, ipsilateral external obliques and spinalis, longissimus and iliocostalis, thoracis, external intercostal, and contralateral internal iliocostalis lumborum, quadratus lumborum, obliques and internal intercostals. For extension: obliques, and psoas. posterior spinal muscles (precise muscles depending upon what level is being extended). Antagonists. To rotation: matching contralateral fibers of rotators as well as contralateral multi- Semispinalis thoracis fidi, semispinalis, external obliques, and exter- Attachments. Transverse processes of T6-Tl0 to nal intercostals, and the ipsilateral internal the spinous processes of C6-T4. oblique and internal intercostal. For extension: Innervation. Dorsal rami of thoracic nerves. spinal flexors (precise muscles depending Function. Acting unilaterally, it rotates the spine upon what level is being extended). contralaterally; bilaterally, it extends the spine. Possible signs of dysfunction of multifidi. Synergists. For rotation: multifidi, rotatores, ipsi- Possible impact on breathing function due to lateral external obliques and external inter- association with intercostal musculature costal, and contralateral internal obliques and Chronic instability of associated vertebral internal intercostals. For extension: posterior segments spinal muscles (precise muscles depending Reduced flexion of spine upon what level is being extended). Restricted rotation (sometimes painfully) Antagonists. To rotation: matching contralateral Pain along spine fibers of semispinalis as well as contralateral Vertebral scapular border pain (referral zone). multifidi, rotatores, external obliques and external intercostals, and the ipsilateral inter- Rotatores longus and brevis nal oblique and internal intercostal. For exten- sion: spinal flexors (precise muscles depending Attachments. From the transverse processes of upon what level is being extended). each vertebra to the spinous processes of the Possible signs of dysfunction of spinalis and second (longus) and first (brevis) vertebra semispinalis. above (ending at C2). Possible impact on breathing function due to Innervation. Dorsal rami of spinal nerves. association with intercostal musculature Function. When these contract unilaterally they Reduced flexion of spine produce contralateral rotation; bilaterally, they Restricted rotation (sometimes painfully) extend the spine. Pain along spine Synergists. For rotation: multifidi, semispinalis Tenderness in laminar groove. muscles, ipsilateral external obliques and 36 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

external intercostal, and contralateral internal chronic weakness (or atrophy) of multifidus is obliques and internal intercostals. For extension: likely to impact strongly on spinal stability - and posterior spinal muscles (precise muscles potentially on breathing function. While short- depending upon what level is being extended). ness and tightness of a muscle are obvious indi- Antagonists. To rotation: matching contralateral cators of dysfunction, it is also important when fibers of rotatores as well as contralateral considering muscular imbalances to evaluate for multifidi, semispinalis, external obliques, and weakness. Actual atrophy of the multifidi has external intercostals, and the ipsilateral inter- been reported in a variety of low back pain set- nal oblique and internal intercostal. For extens- tings. As Liebenson (1996) observes: 'The initial ion: spinal flexors (precise muscles depending muscular reaction to pain and injury has tradi- upon what level is being extended). tionally been assumed to be an increased tension Possible signs of dysfunction of rotatores. and stiffness. Data indicates inhibition is at least Pain and tenderness as associated vertebral as significant. Tissue immobilisation occurs sec- segments, tenderness to pressure or tapping ondarily, which leads to joint stiffness and disuse applied to the spinous processes of associated muscle atrophy. vertebrae Possible impact on breathing function due to Serratus posterior superior association with intercostal musculature. Attachments. Spinous processes of C7-T3 attach Spinal musculature: implications for to the upper borders and external surfaces of thoracic function ribs 2-5, lateral to their angles. Innervation. Intercostal nerves (T2-5). Multifidi and rotatores muscles comprise the Function. Uncertain role but most likely elevates deepest layer and are responsible for fine control the ribs (Gray 1995). of the rotation of vertebrae. They exist through the Synergists. Diaphragm, levatores costarum entire length of the spinal column, and the multi- brevis, scalenus posterior. fidi also broadly attach to the sacrum after becom- Antagonists. Internal intercostals. ing appreciably thicker in the lumbar region. Possible signs of dysfunction of serratus poster- These muscles are often associated with verte- ior superior. bral segments which are difficult to stabilize and Pain that seems to be deep to the scapula should be addressed throughout the spine when Pain may radiate over the posterior deltoid, scoliosis is presented along with the associated down the back of the arm and the ulnar portion intercostal muscles and pelvic positioning. of the hand, and to the smallest finger Trigger points in rotatores tend to produce Numbness into the ulnar portion of the hand rather localized referrals, whereas those in the Possible impact on breathing function via asso- multifidi refer locally and also to the suboccipital ciation with diaphragm and ribs. region, medial scapular border, and top of shoul- der. These local (for both) and distant (for multi- Serratus posterior inferior fidi) patterns of referral continue to be expressed through the length of the spinal column. In fact, Attachments. Spinous processes of Tll-L3 and the lower spinal levels of multifidi may even the thoracolumbar fascia to the inferior borders refer to the anterior thorax or abdomen. of the lower four ribs. Innervation. Intercostal nerves (T9-12). Function. Depresses lower four ribs and pulls Multifidus and the abdominals them posteriorly, not necessarily in respiration Multifidus should co-contract with transversus (Gray 1989). abdominis to assist in low back stabilization Synergists. Internal intercostals. (Richardson & Jull1995) which suggests that any Antagonists. Diaphragm. THE STRUCTURE AND FUNCTION OF BREATHING 37

Possible signs of dysfunction in serratus poste- Antagonists. Internal intercostals, serratus poste- rior inferior. rior inferior, elastic elements of thorax. Leg length differential Possible signs of dysfunction of levatores Rib dysfunction in lower four ribs costarum. Lower backache in area of the muscle Rib dysfunction Scoliosis. Breathing dysfunctions, especially ribs locked in elevation Vertebral segmental facilitation Levatores costarum longus and Scoliosis. brevis (Fig 1.19) Special notes on levatores costarum. The leva- Attachments. Longus: tips of transverse tores costarum appear innocuous in their processes of T7-Tl0 to the upper edge and small, short passage from the transverse external surface of the tubercle and angle of process to the exterior aspect of the ribs. the second rib below. Brevis: tips of transverse However, this advantageous placement, processes of C7-Tll to the upper edge and directly over the costovertebral joint, places external surface of the tubercle and angle of them in a powerful position to rotate the ribs the next rib below. during inhalation. Simons and colleagues Innervation. Dorsal rami of thoracic spinal nerves. (1998) state: ‘They elevate the rib cage with Function. Elevate the ribs: contralateral spinal effective leverage. A small upward movement rotation, ipsilateral flexion, and bilaterally of the ribs so close to the vertebral column is extends the column. greatly magnified at the sternum.’ Synergists. For rib elevation: serratus posterior superior, external intercostals, diaphragm, lntercostals (Fig. 1.12) scalenes. Attachments. External, internal, and innermost lie in three layers, with the external outermost and attach the inferior border of one rib to the superior border of the rib below it. (See special notes below for direction of fibers.) Innervation. Corresponding intercostal nerves. Function. For respiration. External: elevates ribs. Internal: depresses the ribs. Innermost: unclear function but most likely acts with internal fibers (Gray 1995). For rotation. External: rotates torso contralaterally. Internal: rotates torso ipsi- laterally. Synergists. For respiration. External: muscles of inhalation. Internal and innermost: muscles of exhalation. For rotation. External: ipsilateral multifidi and rotatores, contralateral internal obliques. Internal: contralateral external obliques, multifidi, and rotatores. Antagonists. For respiration. External: muscles of exhalation. Internal and innemost: muscles of inhalation. For rotation. External: contralateral multifidi and rotatores, ipsilateral internal Figure 1.19 Levatores costae elevate and ‘spin’ ribs during inhalation. (Reproduced with kind permission from Chaitow obliques. Internal: ipsilateral external obliques, & Delany 2000.) multifidi, and rotatores. 38 MULTIDISCIPLINARY APPROACHES TO BREATHING PATTERN DISORDERS

Possible signs of dysfunction in intercostals. and the arcuate ligaments, thereby forming a Respiratory dysfunctions, including dysfunc- circular attachment around the entire inner tional breathing patterns and asthma surface of the thorax. Scoliosis Innervation. Phrenic nerves (C3-5) for motor Rib dysfunctions and intercostal pain and lower 6-7 intercostal nerves for sensory Cardiac arrhythmia. (Gray 1995, Simons et a1 1998). Special notes on intercostals. Whereas the inter- Function. Principal muscle of inspiration by nal intercostal muscles attach to the ribs and drawing its central tendon downward to stabi- fully to the costal cartilages, the external inter- lize it against the abdominal viscera, at which costals attach only to the ribs, ending at the time it lifts and spreads the lower ribs. lateral edge of the costal cartilages with the Synergists. Accessory muscles of inhalation. external intercostal membrane expanding the Antagonists. Elastic recoil of thoracic cavity and remaining few inches to the sternum. accessory muscles of exhalation Possible signs of dysfunction in the diaphragm. The external and internal intercostal fibers lie Dyspnea or any breathing difficulty (after in opposite directions to each other with the ruling out more sinister causes) external fibers angling inferomedially and the Dysfunctional breathing patterns internal fibers coursing inferolaterally when Chronic respiratory problems (asthma, chronic viewed from the front. These fiber directions cough, etc.) coincide with the direction of external and inter- ‘Stitch’ in the side on exertion nal obliques and provide rotatorial movement of Chest pain the torso and postural influences in addition to Hiccup respiratory responsibilities (Simons et a1 1998). External compression from tight-waisted The role these muscles play in quiet breathing clothing. is uncertain, with some texts suggesting involve- Special notes on the diaphragm ment only during forced respiration (Platzer The diaphragm is a dome-shaped muscle with a 1992). Simons and colleagues (1998) discuss pro- central tendon whose fibers radiate peripherally gressive recruitment depending upon degree of to attach to all the margin of the lower thorax, forced respiration. Intercostals may also provide thereby forming the floor of the thoracic cavity. rigidity to the thoracic cage to prevent inward It attaches higher in the front than in the side pull of the ribs during inspiration. or the back. When this muscle contracts, it The subcostalis muscles (when present) are increases vertical, transverse, and anteroposte- usually only well developed in the lower internal rior diameter of the internal thorax (Kapandji thoracic region. Their fiber direction is the same 1974) and is therefore the most important as that of internal and innermost intercostals and muscle in inspiration. they span across the internal surface of one or A brief summary of some of the diaphragm’s two ribs rather than just the intercostal space. key attachments and features indicates the They probably have a similar function to the complex nature of this muscle: deeper intercostal muscles (Gray 1995, Platzer 1992, Simons et a1 1998). 0 The sternal part of the diaphragm arises from the internal surface of the xiphoid process Interior thorax (this attachment is sometimes absent) 0 The costal part arises from the internal Diaphragm aspects of the lower six ribs, ‘interdigitat- Attachments. Inner surfaces of lower 6 ribs and ing with the transverse abdominis’ (Gray their costal cartilages, posterior surface of 1995) xiphoid process (or sternum), and the body of 0 The lumbar part arises from two aponeu- the upper 1-4 lumbar vertebrae, vertebral discs rotic arches (medial and lateral lumbocostal THE STRUCTURE AND FUNCTION OF BREATHING 39

arches or arcuate ligaments) as well as from 0 The crura ascend and converge to join the the lumbar vertebrae by means of two crura central tendon (Fig. 1.20) (pillars) 0 With attachments at the entire circumference 0 The lateral crura is formed from a thick of the thorax, ribs, xiphoid, costal cartilage, fascia1 covering which arches over the upper spine, discs, and major muscles, the various aspect of quadratus lumborum, to attach components of the diaphragm form a central medially to the anterior aspect of the trans- tendon with apertures for the vena cava, verse process of L1, and laterally to the aorta, thoracic duct, and esophagus inferior margin of the 12th rib 0 When all these diaphragmatic connections 0 The medial crura is tendinous in nature and are considered, the direct influence on respir- lies in the fascia covering psoas major atory function of the lumbar spine and ribs, 0 Medially it is continuous with the corres- as well as psoas and quadratus lumborum, ponding medial crura, and also attaches to becomes apparent. the body of L1 or L2. Laterally it attaches to the transverse process of L1 Transversus thoracis (Fig. 1.21) The crura blend with the anterior longitudi- nal ligament of the spine, with direct con- Attachments. Inner surface of the body of sternum nections to the bodies and intervertebral and xiphoid process superiolaterally to the discs of L1,2 and 3 lower borders of the 2nd-6th costal cartilages.

Figure 1.20 Inferior view of diaphragm. (Reproduced with kind permission from Gray 1995.) 40 MULTIDISCIPLINARY APPROACHES TO BREATHING PAlTERN DISORDERS

Figure 1.21 Posterior view of transversus thoracis. (Reproduced with kind permission from Chaitow & DeLany 2000.)

Innervation. Intercostal nerves (2-6). powerful sensations, with even light contact Function. Depresses the costal cartilages during sometimes producing reflex contractions of the exhalation, ribs 2-6. abdomen or chest with feelings of nausea and Synergists. Muscles of exhalation. choking, as well as anxiety, fear, anger, laugh- Antagonists. Muscles of inhalation. ter, sadness, weeping, and other emotions. Possible signs of dysfunction of transversus Latey believes that its closeness to the internal thoracis thoracic artery is probably significant since, Inadequate lifting of the sternum during when it is contracted, the muscle can exert inhalation, if shortened direct pressure on the artery. He believes that Inadequate excursion of upper ribs during physiological breathing involves a rhythmical exhalation (’elevated ribs’), if lax. relaxation and contraction of this muscle and Special notes on transversus thoracis that rigidity is often seen where ‘control’ This muscle (also called the sternocostalis or dampens the emotions which relate to it. triangularis sterni) lies entirely on the interior In the following chapter, patterns of dysfunc- chest and is not available to direct palpation. It tional breathing will be described. Functional varies considerably, not only from person to changes always have structural implications, person, but also from side to side in the same either as part of the etiology, or as a conse- person (Gray 1995), and is sometimes absent quence. Keeping in mind the structure while (Platzer 1992). considering functional and dysfunctional Latey (1996) reports that the transversus behaviour allows for clinical choices and thoracis muscle has the ability to generate strategies to evolve. THE STRUCTURE AND FUNCTION OF BREATHING 41

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