Background Statistics ó Increased life expectancy increases the importance of maintaining mobility ó Death due to falls in the 80+ year old population (185.6 Keith Khoo PT per 100,000) is almost as high as MVA deaths in the accident prone 15-29 year old group (21.5 MVA deaths per 100,000)(Winter 1995) ó Virtually all musculoskeletal disorders result in some degradation of the balance control system (Byl 1992)

Background Statistics Background Statistics

ó CNS adapts for loss of function which may not be apparent ó 50% of falls occur during some form of locomotion (Ashley until patient is temporarily deprived of the compensating et al 1977, Gabell et al 1985, Overstall et al, 1977, Prudham et al 1981) system ó System is challenged most during: ó Vestibular patients that have an excessive reliance on vision ó Initiating and termination of gait become unstable when they close their eyes or when they are in a darkened room ó Turning ó Pathologies that affect balance include: ó Avoiding obstacles (altering step length, changing ó orthopedic problems (whether lower extremities or spine) direction or stepping over an obstacle) ó Neurological (head injury, stroke, cerebellar disease, PD, MS, ó Bumping into objects or people cerebral palsy) ó Peripheral neuropathies ó Amputations

Vestibular Input

Balance and Vestibular Dysfunction

An inability to control the body's center of mass relative to Visual Input specified limits. Balance and gait testing in patients with complaints of instability is warranted Basford, et al. An Assessment of Gait and Balance Deficits After Traumatic Brain Injury. Arch Phys Med Rehabil Vol 84, March 2003

Proprioceptive Input

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1 Sensory Organization Theory Sensory Organization Theory ó Perception of orientation in relation to gravity, the support surface and the surrounding objects requires a combination of information from vision, the vestibular ó Example: when a person stands next to a large bus that system of the inner ear and the somatosensation (skin, suddenly begins to move, momentary disorientation or pressure receptors on the feet plus muscle and joint imbalance may result. A fraction of a second is required to receptors which signal movement of a particular body decide whether the bus is moving forward or the body is part) swaying back. In this sensory conflict situation, the brain must select the orientationally accurate inputs ó No one sense directly measures the position of the body’s (somatosensory and vestibular) and ignore the inaccurate COG one or vision. ó Vision measures orientation of the eyes in relation to surrounding objects ó Somatosensation provides information regarding the support surface ó Vestibular system is not referenced to external objects, but rather to internal, inertial-gravitational reference determining the orientation of the head in space

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Sensory Organization Theory Sensorimotor – Visual Input ó Special nerve endings or sensory receptors in the back of your eye ó Under most conditions, somatosensory and vision dominate the (retina) are called rods and control of orientation and balance. Both are more sensitive than cones the vestibular system to subtle movements in the COG position, ó These receptors are sensitive to but both are more prone to provide erroneous orientation light information as in the case of the moving visual field ó When light rays strike them, ó Somatosensory information must be ignored if the supporting their nerve fibers send impulses surface is thickly padded or moving to your brain that provide your brain with visual clues that aid in ó If both the somatosensory and the vision inputs are inaccurate, balance. the vestibular system is the only orientational sense. ó For example, when you are ó The combination of senses is dependent upon the condition in outside, buildings are aligned which a person is performing straight up and down, or sidewalks are straight out in ó Because redundant sensory orientation information is available, front of you. people can stand and walk without vision, upon unstable surfaces and even without vestibular input

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Sensorimotor – Visual Output Sensorimotor – Visual Output ó The motor impulses that go to eyeballs coordinate their In a person with a healthy vestibular system, normal fast eye movement so that clear vision is maintained while the movements (nystagmus) can be observed in the light when head is moving either actively (running, watching a tennis the head turns slowly from left to right and back again. match) or passively (sitting in a moving car). The The eyes will move quickly in the same direction that the movement of the eyes while the head is in motion is controlled automatically by the vestibular system. head is turning. These same eye movements occur even in the dark. ó When the head is not moving, the number of impulses from the right side is equal to the number of impulses coming from the left side. As the head turns toward the right, the number of impulses from the right semicircular canals increases, and the number from the left decreases. This difference controls eye movements and allows for clear vision as the head is turning.

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2 Sensorimotor – Vestibular Input Sensorimotor – Vestibular Input ó The inner ear or labyrinth is a complex series of ó Part of each labyrinth, or inner ear, is a snail-shaped organ passageways and chambers within the bony skull. called the cochlea. It functions in hearing. Located right ó Within these passageways are tubes and sacs filled with a next to the cochlea is the part of the inner ear that has to fluid called endolymph. do with balance. This part is called the vestibular apparatus. On each side of the head it is composed of ó Around the outside of the tubes and sacs is a different fluid, the perilymph. three semicircular canals and a utricle and saccule. Each of the semicircular canals is located in a different ó Both of these fluids are of precise chemical compositions, ó and are different. plane in space. They are located at right angles to each other and to those on the opposite side of your head. At ó The mechanism in the inner ear regulates the amount and the base of each canal is a swelling (ampulla) and within composition of these fluids which is important to the these ampullae are located the sensory receptors for each proper functioning of your inner ear. canal.

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Sensorimotor – Vestibular Input Sensorimotor – Vestibular Input ó Inside a semicircular canal. The sensory receptor (cupula) is attached at its base, but the top of it remains free. When the head moves in the direction in which this canal is located, the endolymphatic fluid within the canal, because of inertia, lags behind. The same thing happens when spinning a glass of water between your hands. When the fluid lags behind, the sensory receptor within that canal is bent. The receptor then sends impulses to the brain. The receptor is only sensitive while it is actually moving -- just like the hairs on the arm. Try to move just one hair -- you can feel it as you bend it. When you stop, you don't feel anything anymore. (Clothes are continually bending hairs -- you are not aware of that.) The same thing happens in the hair cells of the cupula.

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Vestibular Input Sensorimotor – Vestibular Output ó In a healthy individual both sides of the vestibular system are functioning properly, the two sides of the vestibular system send symmetrical impulses to the brain. That is, the impulses coming from the right side conform to the impulses coming from the left side. ó All of the sensory input concerning balance, from the eyes, from the muscles and joints, and from the two sides of the vestibular system, is sent to the brain stem, where it is sorted out and integrated.

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3 Sensorimotor – Somatosensory Input Sensorimotor – Somatosensory Output ó The input that the brain receives from muscles and joints comes from sensory receptors that are sensitive to stretch or pressure ó The motor impulses that are sent from the brain to the in the tissue that surrounds them. As legs, arms, or other parts other muscles of the body control their movement so that of the body moves, the receptors respond to the stretch of the balance can be maintained whether in sitting, standing, or muscles surrounding them and send impulses through many turning cartwheels. sensory nerve fibers to the brain. ó Some of the impulses that leave the brain stem go back to ó Especially important are the impulses that come from the neck, the cerebral cortex, carrying information to the thinking which indicates the direction in which the head is turned, and centers that tell the body it's okay to see trees whirling in the impulses that come from the ankles, which indicate the circles when turning cartwheels. When practicing these movement or sway of the body in relation to the floor when and similar new activities, the brain learns to "read" standing. This kind of input provides the brain with information different kinds of sensory input as normal. about the standing surface -- whether it is hard or soft, bumpy or smooth.

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Sensorimotor – Somatosensory Output Sensorimotor - Integration ó This is exactly what happens as a baby learns to balance through ó The brain stem also receives input from two other areas of practice and repetition. The impulses from the sensory receptors to the brain -- the (coordination center), and the the brain stem and out to the muscles form a pathway. With repetition, it becomes easier for the impulses to travel over the cerebral cortex, which functions in thinking and memory. same network or pathway, until many activities of keeping balance As the brain stem is integrating all the input it receives becomes automatic. Physiologists say that these nerve pathways concerning balance, the cerebellum may contribute become "facilitated." This is the reason why dancers and athletes information about automatic movements that have been practice their activities over and over again. Even very complex movements become almost automatic over a period of time. learned through constant practice, e.g. adjustments in Anyone who has learned to ride a bicycle, swim, or ski can relate to balance needed to serve a tennis ball. this idea. This is also the basis for therapy in treating people with a ó The cerebral cortex contributes previously learned damaged vestibular system -- the exercises mimic the movements that make them feel dizzy and lose their balance. After a time, the information. For example, you have learned that icy brain "learns" that the input from this activity is "normal" for the sidewalks are slippery and that you have to step on them damaged system, and the side effects of dizziness and balance in a different way in order to keep your balance. decrease.

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Sensorimotor - Integration Balance Control – Postural Stability

ó As integration of all the sensory input takes place, the Essential to balance control is the condition of postural brain stem sends out impulses along motor-nerve fibers stability. that begin in the brain stem and end in the muscles. ó The state whereby the body is able to effectively and ó These muscles make the head and neck, the eyes, the legs, functionally manipulate combinations of mobility and and the rest of the body move and allow the maintenance stability in the gravitational field. of balance and have clear vision while the body is in ó Two components to postural stability: motion. ó equilibrium and ó orientation.

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4 Balance Control – Postural Stability Balance Control – Postural Stability

Equilibrium: ó Balance will be effected when the center of mass of an object ó whereby the totality of sensorimotor systems controls the projects within the object’s base of support. body’s center of mass with respect to its base of support so ó An object becomes unstable when this fundamental as to either allow for purposeful movement, or to resist condition is not met. perturbations. ó In the living organism, however, the sensorimotor system Orientation: allows for contrived instability-- whereby the center of mass ó whereby the totality of sensory input is acted upon by the projects beyond the base of support-- followed by recovery motor system to effect optimal functional alignment. (when we walk, for example).

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Balance Control – Limits of Stability Balance Control– Mechanical Limits of Stability ó The degree to which the individual is able to displace one’s center of mass outside one’s base of support without falling ó Describes the area about which the individual is able to move or losing one’s stance is an important indicator of balance without shifting the base of support. control; it is referred to as one’s limits of stability. ó Depends on the musculoskeletal and neuromuscular ó Limits of stability are described in terms of two components: capabilities of the individual. ó mechanical limits of stability and ó As these capabilities are diminished, so the mechanical limits ó internal representation of stability. of stability decrease as well ó Sway envelope 12 o anterior & posteriorly; 16 o laterally ó If the COG alignment is forward, backward or to either side, a small sway envelope can be tolerated ó Sudden falls occur because small oscillations are sufficient to extend the COG beyond the limits of stability

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Balance Control– Balance Control– Mechanical Limits of Stability Mechanical Limits of Stability

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5 Balance Control – Balance and Gait Internal Representation of Stability ó Walking messages are initiated by the motor and premotor cortex and modified by the subcortical nuclei, brainstem, and ó Refers to one’s self-perceived limits of stability, that is, the area about which the individual perceives movement can cerebellum. occur without shifting the base of support. ó These all activate the spine's central pattern generator, which ó This neural representation of stability may be either less or coordinates arm and leg movements into rhythmic gait. greater than the (true) mechanical limits of stability. ó Proprioceptive, visual, and vestibular inputs reach the spinal ó Where it is less, the individual may be excessively fearful, and central pattern generator and affect its output. the fear, in turn, may diminish performance to the point of increasing the risk for falls ó The ability to stand and walk normally is therefore dependent ó Where it is greater, the individual may be at increased risk on input from several systems, including visual, vestibular, due to habitual over-estimation of his or her capabilities. cerebellar, motor, proprioceptive and sensory. ó Balance and gait preferably requires an intact brain, , and sensory system. 31 © Copyright K2 Seminars

Normal Gait Balance and Gait ó As the body moves forward, one limb typically provides support while the other limb is advanced in preparation for its role as the ó Some changes in gait, balance, and sensorimotor support limb. The gait cycle (GC) is composed of stance and swing function occur as a result of disease directly affecting phases. The stance phase is further subdivided into three these systems, although many are age-related. segments including: ó Gait and balance abnormalities occur in 8-19% of older ó Initial double stance. people, in 14% of individuals aged over 65 years, and in ó Single limb stance. 50% of individuals aged over 85 years. ó Terminal double limb stance. Martin MP, O’Neill D ; Vascular higher-level gait disorders--a step in the right ó Duration of each aspect of stance decreases as walking velocity direction? Lancet. 2004 Jan 3; 363(9402):8. increases. The transition from walking to running is marked by Sanders RD et al; Gait and its assessment in psychiatry, Psychiatry (Edgmont) July 2010 7(7):38-43. elimination of double support. ó A stride is the equivalent of a gait cycle. The duration of a stride is the interval between sequential initial floor contacts by the same limb.

Gait Assessment Gait Assessment Stance Phase of Walking Swing Phase of Walking

— Swing phase applies to the time when the foot is in the air % OF DOUBLE LEG SINGLE LEG DOUBLE LEG for limb advancement GAIT STANCE STANCE STANCE — Swing begins as soon as the toe is lifted from the floor (toe CYCLE 10% 40% 10% off) and end with initial contact of the foot (heel strike)

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6 Gait Assessment Gait Cycle Strength Changes with Age ó Strength peaks in the mid-20s and declines only a little until the fifth decade, after which it falls off much faster. ó All sensory functions also diminish with age, although again this is slow. ó Gait speed remains stable until the seventh decade and slows modestly after this. ó Age-related changes in the balance of older persons result in compensatory responses that meet routine needs but may be ineffective under demanding circumstances. As a result, the mild age-related decreases in strength and balance may contribute to the increased incidence of falls in older people. — Stride length measures the initial and second contact of the same ó Loss of function caused by disease is of greater impact than age- foot related change, but it will be superimposed on that caused by age and thus both may contribute to a failure of mobility. — Step length is the interval between initial contact of each foot Wolfson L;Gait and balance dysfunction: a model of the interaction of age and — Step length of the left and right leg make up one stride length disease. Neuroscientist. 2001 Apr;7(2):178-83. 37 © Copyright K2 Seminars

Walking Posture and Age Limb Motion and Age ó Walking posture changes with age ó Cadence (rhythm) does not change with age: ó Unless older patients have diseases such as osteoporosis with kyphosis, they walk upright with no forward lean. ó Everyone has a preferred cadence, which relates to leg length ó Older people also walk with about a 5° greater 'toe out', possibly due and usually represents the most energy-efficient rhythm for to a loss of hip internal rotation or in a subconscious strategy to individual body structure. increase stability. ó Ground clearance as the foot swings is the same in elderly as in ó Tall people take longer steps at a slower cadence. younger people. ó Short people take shorter steps at a faster cadence. ó Gait velocity remains stable until about the age of 70, then falls about 15% per decade for normal gait. Velocity is lower because older people take shorter steps: ó One explanation for this is that calf muscles are weaker and cannot produce sufficient plantar flexion. ó Another is that the elderly are reluctant to generate plantar flexion power because of poor balance and poor control of the center of mass whilst standing on one foot momentarily.

GAIT ASSESSMENT Limb Motion and Age STANCE PHASE OF WALKING ó Double stance (the time when both feet are on the ground) increases with age - from 18% of a total gait cycle in young adults to approximately 26% in healthy elderly people: ó During double stance, the centre of mass is between the feet, which is a stable position. ó Increased time in the double stance position reduces momentum and therefore reduces time for the swing leg to advance, contributing to short step length. ó Increased double stance may be needed on uneven ground or when balance is impaired, so that step length is compromised for stability. ó Elderly people with a fear of falling increase their double stance % OF DOUBLE LEG SINGLE LEG DOUBLE LEG time. NORMAL 1 GAIT STANCE STANCE STANCE 1 Kemoun G, Watelain E, Defebvre L, Guieu JD, et al. (2002). Postural strategies and 10% 40% 10% falls in elderly and in parkinsonism. Annales de Readaptation et de Medecine CYCLE Physique 45(9):485-492. 20% 20% 20% FALLER

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7 Gait Assessment Gait Speed Norms (ft/sec) Gait Cycle

AGE (YEARS) MALE FEMALE ó NORMAL AGED GAIT PATTERN 20S 3.57 3.47 ó Reduced stride length 30S 4.17 3.81 ó Even right & left length 40S 3.72 3.53 ó Decreased gait speed 50S 3.07 3.59 60S 3.11 2.85 ó FALLER’S GAIT PATTERN 70S 3.08 2.79 ó Reduced stride length ó Bohannon RW et al. Comfortable and maximum walking speed of adults aged 20-79 ó Increased step width years: Reference values and determinants. Age Aging 1997; 26:15-19 ó Fritz, S., & Lusardi, M. (2009). Walking speed: The sixth vital sign (white ó Uneven right & left length paper). Journal of Geriatric Physical Therapy, 32(2), 2-5. ó Lusardi MM et al. Comfortable and fast gait speeds of the frail community-living ó Decreased gait speed older adults. CSM paper 2002 43 © Copyright K2 Seminars 44 © Copyright K2 Seminars

Gait Assessment Joint Motion Changes and Age Characteristics of Fallers ó Ankle plantar flexion is reduced during the late stage of stance, ó Usually stop walking when talking (spinal loop algorithm just before the back foot lifts off. missing – motor cortex takes over) ó Maximal ankle dorsiflexion is not reduced. ó Fear of falling resulting in shorter singe leg stance and ó Studies have found a strong association between the severity of decreased stride length reducing forward momentum allowing age-related white matter changes and the severity of gait and more time for balance recovery motor compromise. Increasing physical activity may reduce the ó Increased step width associated risks .Baezner H. el al; Association of gait and balance disorders with age- ó Stride to stride variability related white matter changes: the LADIS study. Neurology. 2008 Mar 18;70(12):935-42. ó The presence of neurological gait abnormalities in the elderly (without dementia) is a significant predictor of the risk of development of dementia - especially non-Alzheimer's dementia. Verghese J, et al; Abnormality of gait as a predictor of non-Alzheimer's dementia. N Engl J Med. 2002 Nov 28;347(22):1761-8.

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Gait Deviations Vestibular Gait ó ó Gait in cerebellar disease ó Patients with unilateral vestibular disorders: ó Gait in Parkinsonism ó Veer to the affected side (as opposed to a generalized ó Frontal gait disorder instability with bilateral vestibular or cerebellar ó Cautious gait disorders). ó Hemiparetic gait ó There is a wide-based gait and their difficulties are ó Paraparetic gait exaggerated by asking them to walk heel-to-toe. ó ó Many patients respond well to a simple home program of ó vestibular rehabilitation head movement exercises. ó Waddling gait ó Gait in neuropathic disorders ó This results in reduced symptoms of imbalance during ó Dementia-related gait stance and gait. ó Gait in psychiatric disorders ó Choreic gait ó Medication-related gait disturbance

8 Angunsri N, Ishikawa K, Yin M, Omi E, Shibata Y, Saito T, Itasaka Vestibular Gait Y. Gait instability caused by vestibular disorders - analysis by ó Vestibular information is important during gait together with tactile sensor. Auris Nasus Larynx. 2011 Aug;38(4):462-8. vision and somatosensory input. 1 2011 Mar 2. ó With galvanic vestibular stimulation, experimentally producing ó Gait analysis by the use of tactile sensors could provide functional imbalance between the two vestibular apparatus, causes in healthy subjects gait deviation to the anodal side. additional important information regarding vestibular patho- 2 ó Gait unsteadiness is a common complaint after vestibular physiology in patients with vestibular system disorders. neuritis and a higher fall risk has been also demonstrated in ó Accordingly, gait performance tests should also be taken into these patients 3 who often need to undertake a vestibular consideration as a vestibular function test for patients with rehabilitation program in order to promote functional recovery. vertigo. 1 Kennedy PM, Carlsen AN, Inglis JT, Chow R, Franks IM, Chua R: Relative contribution of visual and vestibular information on the trajectory of human gait. Exp Brain Res 2003, 153:113-7. 2 Fitzpatrick C, Wardman DL, Taylor JL: Effects of galvanic vestibular stimulation during human walking. J Physiol 1999, 3 Herdman SJ, Blatt P, Schibert MC, Tusa RJ: Falls in patients with vestibular deficits. Am J Otol 2000, 21:847-51.

Vestibular Gait Vestibular Gait ó Previous studies have shown in these patients spatio-temporal gait ó The presence of a cognitive-vestibular interaction and the changes, disruption of head-trunk coordination and decrease of head complaint of poor concentration, memory impairment and movements. 1-6 1 disrupted navigation 2 has been also highlighted in vestibular 1 Ishikawa K, Cao ZW, Wang Y, Wong WH, Tanaka T, Miyzaki S, Toyoshima I: Dynamic locomotor function in normals and patients with vertigo. Acta Otlaryngol 2001, 121:241- patients. 4. 2 Patten C, Horak FB, Krebs DE: Head and body center of gravity control strategies: adaptation following vestibular rehabilitation.Acta Otolaryngol 2003, 123:32-40. 3 Tucker CA, Ramirez J, Krebs DE, Riley PO: Center of gravity dynamic stability in normal and vestibulopathic gait.Gait Posture 1998, 8:117-23. 1 Hanes DA, McCollum G: Cognitive-vestibular interactions: a review of patient 4 Cavanaugh JT, Goldvasser D, Mc Gibbon CA, Krebs DE: Comparison of head- and body- difficulties and possible mechanisms. J Vestib Res 2006, 16:75-91. velocity trajectories during locomotion among healthy and vestibulopathic subjects. J Rehabil Res Dev 2005, 42:191-8. 2 Peruch P, Borel L, Gaunet F, Thinus-Blanc G, Magnan J, Lacour M: Spatial performance 5 Mamoto Y, Yamamoto K, Imai T, Tamura M, Kubo T: Three-dimensional analysis of human of unilateral vestibular defective patients in non visual versus visual navigation. locomotion in normal subjects and patients with vestibular deficiency. Acta J Vestib Res 1999, 9(1):37-47. Otolaryngol 2002, 122:495-500. 6 Pozzo T, Berthoz A, Vitte E, Lefort L: Head stabilization during locomotion. Perturbations induced by vestibular disorders. Acta Otolaryngol Suppl 1991, 481:322-7.

Vestibular Gait Vestibular Gait ó The dual task (DT) paradigm, by simultaneously employing ó Cognitive and motor interference during gait has been balance and cognitive tasks, has been used in recent years to studied in pathologies such as stroke , Parkinson disease shed light on motor and cognitive interference 1 in healthy young 1 2 people, 2, 3 elderly subjects 4 and patients. and dementia. 3

1 Woollacott M, Shumway-Cook A: Attention and the control of posture and gait: a 1 Plummer-D'Amato P, Altmann LJP, Saracino D, Fox E, Behrman AL, Marsiske review of an emerging area of research.Gait Posture 2002, 16:1-14. M:Interactions between cognitive tasks and gait after stroke: a dual task study. 2 Siu K, Woollacott M: Attentional demands of postural control: the ability to Gait Posture 2008, 27:347-51. selectively allocate information-processing resources. Gait Posture 2007, 25:121- 6. 2 O'Shea S, Morris ME, Iansek R: Dual task interference during gait in people with 3 Pellechia GL: Postural sway increases with attentional demands of concurrent Parkinson disease: effects of motor versus cognitive secondary tasks. Phys cognitive task. Gait Posture 2003, 18:29-34. Ther 2002, 82:888-97. 4 Faulkner KA, Redfern MS, Rosano C, Landsittel DP, Studenski SA, Cauley JA, Zmuda 3 Allali G, Kressig RW, Assal F, Herrmann FR, Dubost V, Beauchet O: Changes in gait JM, Simonsick EM, Kritchevsky SB, Newman AB: Reciprocal influence of while backward counting in demented older adults with frontal lobe dysfunction. concurrent walking and cognitive testing on performance in older adults. Gait Posture 2006, 24:182-9. Gait Posture 2007, 26:572-6.

9 Alberto Nascimbeni, Andrea Gaffuri, Arminio Penno and Mara Vestibular Gait Tavoni. Dual task interference during gait in patients with ó These studies are based on the assumption that cognitive unilateral vestibular disorders. Journal of NeuroEngineering and resources are limited and can be undermined by the execution of Rehabilitation 2010, 7:47 concurrent tasks, especially when pathologies limit the ó Vestibular patients show slower and unsteady gait; they have performance by a reduction of attentional resources available or also been shown to need greater cognitive resources when by the need of increased attention to carry out usual tasks owing carrying out balance and cognitive dual tasks (DT). This study investigated DT interference during gait in a middle-aged group to motor-sensory impairments. of subjects with dizziness and unsteadiness after unilateral ó The degree of impairment of motor-sensory integration during vestibular neuronitis and in a healthy control group. DT will depend on the amount of attentional resources required ó The main aim of this study was to explore DT interference in a by the proposed tasks. 1, 2 homogeneous group of patients with unilateral vestibular impairment while performing backward counting during gait, 1 Pellechia GL: Postural sway increases with attentional demands of concurrent cognitive comparing the performances during single and DT. A second aim task. Gait Posture 2003, 18:29-34. was to find out differences if any with an healthy control group. 2 Yardley L, Gardner M, Bronstein A, Davies R, Buckwell D, Luxon L: Interference between ó Since gait and balance impairments increase with age, together postural control and mental task performance in patients with vestibular disorder and with the need of attentional resources, causing more DT healthy controls. J Neurol Neurosurg Psychiatry 2001, 71:48-52. interferences , older adults were not recruited in this study.

• Patients and control subjects were included if their age was ó The patients were first assessed by a neurotologist and between 18 and 65 years and without other pathologies underwent alternating binaural bithermal caloric stimulation, interfering with gait, balance and cognition. head positioning test and audiometry. • 14 patients with unilateral vestibular impairment after ó Vestibular tests showed vestibular neuritis and 17 healthy control subjects were ó 7 patients with right hypofunction evaluated. ó 3 with left hypofunction • Mean age, height and weight of the patient group, made up ó 2 with right loss of vestibular function of ó 2 with left loss of vestibular function • 8 female and 6 male, ó Brain MRI was also carried out in order to rule out other • were 45.2 ± 8.1 years, vestibular or central nervous system pathologies that can affect • 169 ± 9.8 cm and 66.4 ± 13.4 Kg respectively balance such as cerebello-pontine angle or white matter • The control group, diseases. ó As these tests did not demonstrate any other pathologies, the • 13 female and 4 male, diagnosis of peripheral unilateral vestibular impairment was • 44.1 ± 7.9 years, confirmed. • 167 ± 10 cm. and 69.8 ± 14.3 Kg respectively

ó STEP 32 gait analysis system (DEM Italia, Leinì, Turin, Italy) was ó Greater foot pressure on the side of the lesion has been found in employed for gait assessment. unilateral vestibular patients during gait with eyes closed. 1 ó Each participant performed three trials. ó Vestibular subjects were found to have increased stride time and double support, lower gait speed and cadence and higher ó The motor single task consisted of walking at self selected speed, 2, 3 back and forth in a well-lit gait laboratory without stopping. The interfoot distance during paced gait but only at increased speed. 4 distance between each turn was of 12 m. The cognitive single task consisted of backward counting aloud 1 Ishikawa K, Cao ZW, Wang Y, Wong WH, Tanaka T, Miyzaki S, Toyoshima I: Dynamic ó locomotor function in normals and patients with vertigo. Acta by 3 while the subjects were comfortably seated. Otlaryngol 2001, 121:241-4. ó During DT participants were asked to walk while backward 2 Tucker CA, Ramirez J, Krebs DE, Riley PO: Center of gravity dynamic stability in counting without any prioritization of cognitive or motor task, normal and vestibulopathic gait. Gait Posture 1998, 8:117-23. and to carry out the test to the best of their abilities. 3 Krebs DE, Goldwasser D, Lockert JD, Portney LG, Gill-Body KM: Is base of support greater in unsteady gait? Phys Ther 2002, 82:138-47. 4 Marchetti GF, Whitney SL, Blatt PJ, Morris L, Vance JM: Temporal and spatial characteristics of gait during performance of the dynamic gait index in people with and in people without balance or vestibular disorders. Phys Ther 2008, 88:640-51.

10 ó The use of a trunk strategy for head stabilization, in order to ó This study is in agreement with previous works suggesting a compensate for a disrupted vestibulo-ocular reflex, 1,2,3 and a balance prioritization during dual task in vestibular patients decrease of head rotations while walking in dark was also with a decrease of mental task performance. demonstrated. 4 ó This behavior might be the consequence of higher cognitive demands required to cope with unilateral vestibular impairment 1 Patten C, Horak FB, Krebs DE: Head and body center of gravity control strategies: adaptation following vestibular rehabilitation. Acta Otolaryngol 2003, 123:32- when multisensory integration and gaze stabilization 1 is needed 40. during motor tasks. 2 Cavanaugh JT, Goldvasser D, Mc Gibbon CA, Krebs DE: Comparison of head- and body-velocity trajectories during locomotion among healthy and vestibulopathic ó This study results extend the hypothesis to a more demanding subjects. J Rehabil Res Dev 2005, 42:191-8. and daily motor task such as gait, requiring greater multiple 3 Mamoto Y, Yamamoto K, Imai T, Tamura M, Kubo T: Three-dimensional analysis of sensory integration. human locomotion in normal subjects and patients with vestibular deficiency. Acta Otolaryngol 2002, 122:495-500. 4 Pozzo T, Berthoz A, Vitte E, Lefort L: Head stabilization during locomotion. 1 Whitney SL, Marchetti GF, Pritcher M, Furman JM: Gaze stabilization and gait Perturbations induced by vestibular disorders. Acta Otolaryngol performance in vestibular dysfunction. Gait Posture 2009, 29:194-8. Suppl 1991, 481:322-7.

Cerebellar Function Cerebellar Function Testing ó The cerebellum is a coordination center that maintains https://www.youtube.com/watch?v=xEI4_St8qUU balance and controls muscle tone through regulatory circuits and complex feedback mechanisms, and assures the precise, temporally well-coordinated execution of all directed motor processes. ó Cerebellar coordination of movement occurs unconsciously. ó The individual components of the cerebellum (vestibulocerebellum, spinocerebellum, and cerebrocerebellum) have different functions in the coordination of movement. ó Other portions of the brain can apparently assume some of the functions of the cerebellum, if necessary, but yet if the disturbance affects not just the cerebellar cortex but also the deep cerebellar nuclei, only minimal recovery is likely to occur.

Cerebellar ó Dysfunction of the cerebellum ó People with cerebellar ataxia may initially present with poor ó This results in a characteristic type of irregular, uncoordinated balance, which could be demonstrated as an inability to stand movement that can manifest itself in many possible ways, such on one leg or perform tandem gait. as asthenia, asynergy, delayed reaction time, and ó As the condition progresses, walking is characterized by a dyschronometria. widened base and high stepping, as well as staggering and ó Individuals with cerebellar ataxia could also display instability lurching from side to side. 1 of gait, difficulty with eye movements, dysarthria, dysphagia, ó Turning is also problematic and could result in falls. hypotonia, and . 1 ó As cerebellar ataxia becomes severe, great assistance and effort 1 Schmahmann JD (2004). "Disorders of the cerebellum: ataxia, dysmetria of thought, are needed in order to stand and walk. and the cerebellar cognitive affective syndrome". J Neuropsychiatry Clin 1 Neurosci 16 (3): 367–78. 1 Schmahmann JD (2004). "Disorders of the cerebellum: ataxia, dysmetria of thought, and the cerebellar cognitive affective syndrome". J Neuropsychiatry Clin Neurosci 16 (3): 367–78.

11 Cerebellar Ataxia ó Dysarthria, an impairment with articulation, may also be Vestibulocerebellum - Function present and is characterized by "scanning" speech that consists ó The vestibulocerebellum receives impulses from the of slower rate, irregular rhythm and variable volume. 1 ó There may also be slurring of speech, of the voice and vestibular apparatus carrying information about the position ataxic respiration. and movements of the head. Its efferent output influences ó Cerebellar ataxia could result with incoordination of movement, the motor function of the eyes and body in such a way that particularly in the extremities. equilibrium can be maintained in all positions and with any ó There is overshooting with finger to nose testing, and heel to movement. shin testing; thus, dysmetria is evident. 1 ó Impairments with alternating movements (dysdiadochokinesia), as well as dysrhythmia, may also be displayed. ó There may also be tremor of the head and trunk (titubation) in individuals with cerebellar ataxia. 1 1 Schmahmann JD (2004). "Disorders of the cerebellum: ataxia, dysmetria of thought, and the cerebellar cognitive affective syndrome". J Neuropsychiatry Clin Neurosci 16 (3): 367–78.

Vestibulocerebellum – Synaptic Vestibulocerebellum – Synaptic Connections Connections ó The following reflex arcs participate in the maintenance of equilibrium (balance). ó From the vestibular organ, impulses travel both directly and indirectly (by way of the vestibular nuclei) to the vestibulocerebellar cortex, and onward to the fastigial nucleus. ó The vestibulocerebellar cortex transmits impulses back to the vestibular nuclei, as well as to the reticular formation; from these sites, the vestibulospinal and reticulospinal tracts and the medial longitudinal fasciculus enter the brainstem and spinal cord to control spinal motor and oculomotor function (next slide). ó These reflex arcs assure stability of stance, gait, and eye position and enable the fixation of gaze.

Vestibulocerebellum Dysfunction ó Dysfunction of the vestibulocerebellum (flocculonodular lobe or Cerebellar Sensory Testing fastigial nucleus) impairs the balance or renders the patient less capable of orienting himself or herself in the earth’s gravitational field Videos\ONE ----- Cerebellar assessment and the control of eye movements or keeping his or her gaze fixed on a stationary object when the head is moving. ó Presents itself with postural instability, in which the person tends to separate his/her feet upon standing, in order to gain a wider base and to avoid titubation (bodily oscillations tending to be forward- backward ones) or astasia. ó The instability is therefore worsened when standing with the feet together, regardless of whether the eyes are open or closed or a negative Romberg's test, or more accurately, it denotes the individual's inability to carry out the test, because the individual feels unstable even with open eyes.

12 Cerebellar Occulomotor Vestibulocerebellum Dysfunction ó Gait is broad-based and unsteady, resembling the gait of a drunken Disturbances individual (). ó Cerebellar disturbances of oculomotor function are manifest as an ó Heel-to-toe walking can no longer be performed. impaired ability to hold one’s gaze on a stationary or moving target ó The unsteadiness is not due to a deficiency of proprioceptive impulses (lesions of the flocculus and paraflocculus). reaching consciousness, but rather to faulty coordination of the ó The result is saccadic pursuit movements and gaze-evoked musculature in response to gravity. nystagmus: if the patient tries to follow a moving object with his or her eyes, square-wave jerks can be observed, i.e., the amplitude of the microsaccades that normally occur in ocular pursuit is abnormally increased, so that they become visible to the examiner.

Cerebellar Occulomotor Nystagmus Disturbances Videos\TWO---Gaze Stability and Spontaneous ó Gaze-evoked nystagmus is more prominent when the eyes move Nystagmus - YouTube2.mp4 toward the side of the cerebellar lesion and diminishes somewhat if the gaze is held to that side; if the eyes are then brought back to the midline, nystagmus in the opposite direction may be seen Videos\TWO POINT FIVE---Square Wave Jerk (rebound nystagmus). Nystagmus - YouTube.mp4 ó Cerebellar lesions can also produce various types of complex nystagmus, such as opsoclonus (rapid conjugate movements of the eyes in multiple planes) or ocular flutter (opsoclonus in the horizontal plane only), whose precise localization has not yet been determined.

Vestibulocerebellum Dysfunction Nystagmus ó Lesions of the vestibulocerebellum may impair the patient’s ability Videos\THREE---Opsoclonus Myoclonus Ataxia to suppress the vestibulo-ocular reflex (VOR), in which turning the head produces saccadic jerks of the eyes. Nystagmus - YouTube.mp4 ó A healthy individual can suppress this reflex by fixing the gaze upon an object, but a patient with a vestibulocerebellar lesion cannot (impaired suppression of the VOR by fixation). ó Furthermore, lesions of the nodulus and uvula impair the ability of the VOR (rotatory nystagmus) to habituate and may lead to the appearance of periodic alternating nystagmus that changes directions every 2–4 minutes.

Demer JL, Honrubia V, Baloh RW. Dynamic visual acuity: a test for oscillopsia and vestibulo-ocular reflex function. Am J Otol. 1994 May;15(3):340-7

13 Spinocerebellum Dynamic Visual Acuity Test ó Dysfunction of the spinocerebellum (vermis and associated areas near the midline) presents itself with a wide-based "drunken Videos\FOUR---Dynamic Visual Acuity Test - sailor" gait (called truncal ataxia), 1 characterised by uncertain starts YouTube.mp4 and stops, lateral deviations, and unequal steps. ó As a result of this gait impairment, falling is a concern in patients with ataxia. ó Studies examining falls in this population show that 74-93% of patients have fallen at least once in the past year and up to 60% admit to fear of falling. 2, 3

1 Blumenfeld H (2002). Neuroanatomy through clinical cases. Sunderland, Mass: Sinauer. pp. 670–671 2 Fonteyn EM, Schmitz-Hübsch T, Verstappen CC, Baliko L, Bloem BR, Boesch S, Bunn L, Charles P, Dürr A, Filla A, Giunti P, Globas C, Klockgether T, Melegh B, Pandolfo M, De Rosa A, Schöls L, Timmann D, Munneke M, Kremer BP, van de Warrenburg BP (June 2010). "Falls in spinocerebellar : Results of the EuroSCA Fall Study". Cerebellum 9 (2): 232–9 3 van de Warrenburg BP, Steijns JA, Munneke M, Kremer BP, Bloem BR (April 2005). "Falls in degenerative cerebellar ataxias". Mov. Disord. 20 (4): 497–500

Cerebrocerebellum Cerebrocerebellum ó Dysfunction of the cerebrocerebellum (lateral hemispheres) presents as ó Dysfunction of the cerebrocerebellum . (continued) These include: disturbances in carrying out voluntary, planned movements by the inability to judge distances or ranges of movement or dysmetria is often extremities (called appendicular ataxia). These include: ó 1 seen as undershooting, hypometria, or overshooting, hypermetria, the ó intention tremor (coarse trembling, accentuated over the execution of required distance or range to reach a target. This is sometimes seen when voluntary movements, possibly involving the head and eyes as well as the limbs and torso); a patient is asked to reach out and touch someone's finger or touch his or her own nose. ó peculiar writing abnormalities (large, unequal letters, irregular 1 underlining); ó the rebound phenomenon, also known as the loss of the check reflex is ó a peculiar pattern of dysarthria (slurred speech, sometimes characterised also sometimes seen in patients with cerebellar ataxia. For example, by explosive variations in voice intensity despite a regular rhythm). when a patient is flexing his or her elbow isometrically against a ó inability to perform rapidly alternating movements, known resistance. When the resistance is suddenly removed without warning, as dysdiadochokinesia. This could involve rapidly switching the patient's arm may swing up and even strike themselves. With an from pronation to supination of the forearm. Movements become more intact check reflex, the patient will check and activate the opposing irregular with increases of speed. 2 triceps to slow and stop the movement. 1

1 Schmitz TJ, O'Sullivan SB (2007). "Examination of Coordination". Physical 1 BlumenfeldH (2002). Neuroanatomy through clinical cases. Sunderland, Mass: Sinauer. pp. 670–671 rehabilitation. Philadelphia: F.A. Davis. pp. 193–225. 2 Schmitz TJ, O'Sullivan SB (2007). "Examination of Coordination". Physical rehabilitation. Philadelphia: F.A. Davis. pp. 193–225.

Sensory Ataxia Midline Ataxia ó The term is employed to indicate ataxia due to ó Clinically, the ataxic syndromes caused by vestibulocerebellar and loss of proprioception, the loss of sensitivity to the positions of spinocerebellar disease are lumped together and are called midline or joint and body parts. equilibratory (gait) ataxias. ó This is generally caused by dysfunction of the dorsal columns of ó The hallmarks of these midline ataxic syndromes are truncal instability manifested by titubation (tremor of the trunk in an anterior-posterior the spinal cord, because they carry proprioceptive information plane at 3-4 Hz) and up to the brain. ó gait ataxia (wide based, irregular steps with lateral veering). ó In some cases, the cause of sensory ataxia may instead be dysfunction of the various parts of the brain which receive positional information, including the cerebellum, thalamus, and parietal lobes.

14 Sensory Ataxia Vestibular Ataxia ó Sensory ataxia presents itself with an unsteady "stomping" gait with ó The term vestibular ataxia is employed to indicate ataxia due to heavy heel strikes, as well as a postural instability that is usually dysfunction of the vestibular system, which in acute and worsened when the lack of proprioceptive input cannot be compensated for by visual input, such as in poorly lit environments. unilateral cases is associated with prominent vertigo, ó Can find evidence of sensory ataxia during physical examination by nausea and vomiting. having the patient stand with his/her feet together and eyes shut. ó In slow-onset, chronic bilateral cases of vestibular dysfunction, ó In affected patients, this will cause the instability to worsen markedly, these characteristic manifestations may be absent, producing wide oscillations and possibly a fall. and dysequilibrium may be the sole presentation. ó This is called a positive Romberg's test. ó Worsening of the finger-pointing test with the eyes closed is another feature of sensory ataxia. ó Also, when the patient is standing with arms and hands extended toward the physician, if the eyes are closed, the patient's finger will tend to "fall down" and then be restored to the horizontal extended position by sudden muscular contractions (the "ataxic hand").

CLINICAL FEATURES OF ACUTE LABYRINTHINE Ataxia - causes VERSUS ACUTE VESTIBULOCEREBELLAR ó Focal lesions DISORDERS ó Exogenous substances Acute Labyrinthine Acute Disorder Vestibulocerebellar Radiation poisoning ó Disorder ó Vitamin B12 deficiency Nystagmus fast phase ó Hypothyroidism Direction of Romberg fall ó Causes of isolated sensory ataxia and past pointing Environmental Vertigo ó Non-hereditary cerebellar degeneration Visual Suppression Yes No ó Hereditary ataxias Brainstem Signs No Not Initially ó Arnold-Chiari malformation Tinnitus/Deafness Occasionally No

ó Wilson's disease Duncan GW, Parker SW, Fisher CM: Acute cerebellar infarction in the PICA territory. Arch Neurol 1975 Jun: 32:364-368 Takemori S, Cohen B: Loss of visual suppression of vestibular nystagmus after flocculus lesions. Brain Res 1974 June 7; ó Gluten ataxia 72:213-224 Hood JD, Korres S: Vestibular suppression in peripheral and central vestibular disorders. Brain 1979 Dec; 102:785-804 ó Sodium-potassium pump Zee DS: Opthalmoscopy in examination of patients with vestibular disorders (Letter). Ann Neurol 1978 Apr; 3:373-374

Treatment Treatment ó Physical therapy requires a focus on adapting activity and ó Current research suggests that, if a person is able to walk with or facilitating motor learning for retraining specific functional motor without a mobility aid, physical therapy should include an exercise program addressing five components: static balance, patterns. 1 A recent systematic review suggested that physical therapy is effective, but there is only moderate evidence to support dynamic balance, trunk-limb coordination, stairs,

this conclusion. 2 The most commonly used physical therapy and contracture prevention. 1 interventions for cerebellar ataxia are vestibular habituation, Frenkel ó it is important that the individual be prescribed and regularly Exercises, proprioceptive neuromuscular facilitation (PNF), and engage in a supplementary home exercise program that balance training; however, therapy is often highly individualized and incorporates these components to further improve long term gait and coordination training are large components of therapy. outcomes. 1 Ilg W, Synofzik M, Brötz D, Burkard S, Giese MA, Schöls L (December 2009). "Intensive coordinative training improves motor performance in degenerative cerebellar ó balance tasks disease". Neurology 73 (22): 1823–30 ó gait 2 Martin CL, Tan D, Bragge P, Bialocerkowski A (January 2009). "Effectiveness of physiotherapy for adults with cerebellar dysfunction: a systematic review". Clinical ó individual activities of daily living Rehabilitation 23 (1): 15–26. 1 Ilg W, Synofzik M, Brötz D, Burkard S, Giese MA, Schöls L (December 2009). "Intensive coordinative training improves motor performance in degenerative cerebellar disease". Neurology 73 (22): 1823–30

15 Treatment Treatment ó Treatment should likely include strategies to manage difficulties ó There are several assessment tools available to therapists and health care with everyday activities such as walking. professionals that assess motor function, balance and coordination are also highly valuable to help the therapist track the progress of their patient, as well ó Gait aids (such as a cane or walker) can be provided to decrease as to quantify the patient's functionality. the risk of falls associated with impairment of balance or poor ó The Berg Balance Scale coordination. ó Functional Gait Assessment or Dynamic Gait Index

ó Coexisting motor deficits, of muscle weakness and decreased ó Scale for the Assessment and Rating of Ataxia 1 endurance that could lead to increasing fatigue and poorer ó Tapping tests – The person must quickly and repeatedly tap their arm or leg movement patterns, need to be addressed while the therapist monitors the amount of dysdiadochokinesia. 2 ó While the improvements are attributed primarily to changes in ó Finger-nose testing 2 – This test has several variations including finger-to- therapist's finger, finger-to-finger, and alternate nose-to-finger. the brain and not just the hip and/or ankle joints, it is still 3 unknown whether the improvements are due to adaptations in 1 Schmitz-Hübsch T, du Montcel ST, Baliko L, Berciano J, Boesch S, Depondt C, Giunti P, Globas C, Infante J, Kang JS, Kremer B, Mariotti C, Melegh B, Pandolfo M, Rakowicz M, Ribai P, Rola R, Schöls L, Szymanski S, the cerebellum or compensation by other areas of the brain. 1 van de Warrenburg BP, Dürr A, Klockgether T, Fancellu R (June 2006). "Scale for the assessment and 1 Ilg W, Synofzik M, Brötz D, Burkard S, Giese MA, Schöls L (December 2009). rating of ataxia: development of a new clinical scale". Neurology66 (11): 1717–20 "Intensive coordinative training improves motor performance in 2 Notermans NC, van Dijk GW, van der Graaf Y, van Gijn J, Wokke JH (January 1994). "Measuring ataxia: quantification based on the standard neurological examination". J. Neurol. Neurosurg. Psychiatr.57 (1): degenerative cerebellar disease". Neurology 73 (22): 1823–30 22–6 3 "OPETA: Neurologic Examination". Online physical exam teaching assistant. The UF College of Medicine Harrell Center. Retrieved 7 May 2012.

Motor Learning Motor Learning ó Motor learning is a change, resulting from practice or a novel experience, in the capability for responding. ó Contextual interference was originally defined as "function interference in learning responsible for memory improvement". ó Often involves improving the smoothness and accuracy of movements and is 1 obviously necessary for complicated movements such as speaking, playing the ó Contextual interference effect is "the effect on learning of the degree of piano, and climbing trees; but it is also important for calibrating simple functional interference found in a practice situation when several tasks must movements like reflexes, as parameters of the body and environment change be learned and are practiced together". 2 over time. ó Variability of practice (or varied practice) is an important component to ó Motor learning research often considers variables that contribute to motor contextual interference, as it places task variations within learning. program formation (i.e., underlying skilled motor behavior), sensitivity of ó Although varied practice may lead to poor performance throughout the error-detection processes, 1,2 and strength of movement schemas. acquisition phase, it is important for the development of the schemata, which ó Motor learning is "relatively permanent", as the capability to respond is responsible for the assembly and improved retention and transfer of motor appropriately is acquired and retained. learning. 1, 5 ó The main components underlying the behavioral approach to motor learning are structure of practice and feedback given on the preparation, anticipation, 1 Barreiros, J.; Figueiredo, T.; Godinho, M. (2007). "The contextual interference effect in and guidance of movement. applied settings". European Physical Education Review 13 (2): 195–208 2 Magill, Richard A.; Hall, Kellie G. (1990). "A review of the contextual interference effect in motor skill acquisition". Human Movement Science 9 (3-5): 241–289. 1 Schmidt, Richard A. (1975). A schema theory of discrete motor skill learning. Psychological Review 82 (4): 225–260. 3 Moxley SE (January 1979). "Schema: the variability of practice hypothesis". J Mot Behav 11 (1): 65–7 2 Adams JA (June 1971). "A closed-loop theory of motor learning". J Mot Behav 3(2): 111– 49.

Motor Learning Specificity of Learning ó Feedback is regarded as a critical variable for skill acquisition and is broadly ó The specificity of learning hypothesis suggests that learning is defined as any kind of sensory information related to a response or most effective when practice sessions include environment and movement. 1 movement conditions which closely resemble those required ó Intrinsic feedback is response-produced — it occurs normally when a movement is made and the sources may be internal or external to the during performance of the task — replicating the target skill body. level and context for performance. 1 ó Typical sources of intrinsic feedback include vision, proprioception and ó It suggests that the benefit of specificity in practice occurs audition. because motor learning is specific to the feedback sources ó Knowledge of performance (KP) or kinematic feedback refers to information available during the process of skill learning. 2 provided to a performer, indicating the quality or patterning of their movement. 1 1 Schmidt, Richard A.; Wrisberg, Craig A. (2004). Motor learning and performance. ó It may include information such as displacement, velocity or joint motion. Champaign, IL: Human Kinetics (page 194) ó KP tends to be distinct from intrinsic feedback and more useful in real-world 2 Proteau, Luc (1992). "On the Specificity of Learning and the Role of Visual tasks. Information for Movement Control". In L Proteau; D Elliott. Vision and Motor Control. Advances in Psychology, Volume 85 (New York: Elsevier Science & 1 Schmidt, Richard A.; Wrisberg, Craig A. (2004). Motor learning and performance. Champaign, IL: Technology). pp. 33–48. Human Kinetics

16 Specificity of Learning Specificity of Learning ó The cerebellum and basal ganglia are critical for motor learning. It is suggested that compensation methods develop through ó Through motor learning the human is capable of achieving very ó skilled behavior, and through repetitive training a degree of pure repetition and to elicit cortical changes (true recovery), automaticity can be expected. individuals should be exposed to more challenging tasks. ó At a cellular level, motor learning manifests itself in the neurons Krakauer JW(February 2006). "Motor learning: its relevance to stroke recovery and of the motor cortex. Using single cell recording techniques, Dr. neurorehabilitation". Curr. Opin. Neurol. 19 (1): 84–90. Emilio Bizzi and his collaborators have shown the behavior of certain cells, known as “memory cells”, can undergo lasting alteration with practice. ó In older subjects with vestibular disorders, gaze stability, as assessed by the Gaze Stabilization Test, is associated with ó Motor learning is also accomplished on the musculoskeletal level. reduced test scores on measures of gait performance (DGI and ó Each motor neuron in the body innervates one or more muscle cells, and TUG). together these cells form what is known as a motor unit. Whitney SL, Marchetti GF, Pritcher M, Furman JM. Gaze stabilization and gait ó For a person to perform even the simplest motor task, the activity of performance in vestibular dysfunction. Gait Posture. 2009 Feb;29(2):194-8 thousands of these motor units must be coordinated.

What is LiteGait? Learning is Dependent on Duration of Everyday Experience ó Postural Control Device ó During the development of independent mobility, an infant… ó Provide posture, balance and weight ó Crawls 60-188 meters/day bearing assistance ó Crawls 1000-3200 steps ó Provide corrected upright position appropriate for ambulation ó Walks 50% of waking hours ó Takes 500 steps in 16 minutes of free play ó Allows therapist to facilitate and cue proper patterns of walking ó Takes 9000 steps/day ó Designed for Partial Weight Bearing ó Covers 2900 meters/day (= 29 football fields!) Gait Therapy

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LiteGait Provides LiteGait Benefits Patients ó Means to lift patient into upright posture ó Distribute supporting forces to meet patient needs to become ó Achieve reduced weight bearing status ó More symmetric in static posture ó Fall Free Environment to walk ó More functional in dynamic gait ó Begin gait training earlier in the rehabilitation process, and at ó Free the therapist to facilitate a lower level of function ó Weight shifting ó Learn to walk with proper upright gait ó Foot placement ó Experience a sense of accomplishment ó Stretch of hip flexors in terminal stance ó Learn to use assistive device over ground ó Knee extension to weight bear mid stance

17 Over Ground Intervention

Cueing Proper Gait Pattern

LiteGait & GaitKeeper

Lite Gait

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