See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/262912731 Rehabilitation of the stability function of psoas major ARTICLE · JANUARY 2002 DOWNLOADS VIEWS 50 38 1 AUTHOR: Sean Gibbons Neuromuscular Rehabilitation Institute 13 PUBLICATIONS 18 CITATIONS SEE PROFILE Available from: Sean Gibbons Retrieved on: 27 July 2015 Rehabilitation of Psoas Major Rehabilitation of the Stability Function of Psoas Major Sean GT Gibbons, Mark J Comerford and Peter L Emerson Introduction attachments constitute individual supplied by branches of the femoral Psoas major is the largest muscle in fascicles. The fascicles of psoas are nerve from L2, 3 and 4 (Gibbons, 1999, cross section at the lower levels of the about the same length within 2001, Gibbons et al, 2001). lumbar spine (McGill et al, 1988). A specimens and have a unipennate Literature Review Summary review of the literature reveals it has fibre orientation. The fibre length A tool was developed to been a poorly investigated muscle and within anterior fascicles range from 3 systematically evaluate literature on there is still controversy concerning its to 8cm and 3 to 5cm in the posterior muscle function, which consisted of true functional role (Gibbons, 1999). fascicles. The fascicles run infero- critical methodological criteria and This may be due to several reasons; its laterally to reach a central tendon general methodological criteria. It was location within the body, which does where they descend over the pelvic divided into sections based on the type not permit routine access with brim and share a common insertion of research project and the methods myolectric electrodes or a clear visual with iliacus to the lesser trochanter used. Each section was given a score with real-time ultrasound imaging, it’s (Gibbons, 2001, Gibbons et al, 2001). based on the criteria within it. Very complex anatomy (Bogduk et al, Psoas also has significant fascial few studies passed the basic 1992), and finally, it is not always relations. The medial arcuate ligament component of the critical considered separately from iliacus is a continuation of the superior psoas methodological criteria. In addition, (hence the name ‘iliopsoas’). A better fascia. The right and left crus make up many studies did not consider psoas understanding of the implications of the spinal attachment of the separately from iliacus or the method the function of psoas major on the diaphragm. They attach to the antero- of assessment was very poor (Gibbons, stability of the lumbo-pelvic region lateral component of the upper three 1999; Gibbons, 2001). may improve clinical management of vertebrae and bodies. The crus and From the literature review, psoas related dysfunction. Research was their fascia overlap psoas and appear major is thought to function as a undertaken to gain an understanding continuous with psoas until they come stability muscle for the lumbar spine of the anatomy, physiology and more anterior and blend with the through axial compression and offers function of psoas major. This involved anterior longitudinal ligament little, or no contribution to range of a systematic review of the literature, (Gibbons, 1999). As psoas descends, spinal movement. (Bogduk et al, dissection studies of psoas major and its infero-medial fascia becomes thick 1992). Andersson et al (1995) state the deep myofascial system. From this, at its lower portion and is continuous that psoas major controls spinal lateral a biomechanical model was with the pelvic floor fascia. This also movement eccentrically and their developed. The purpose of this paper forms a link with the conjoint tendon, results indicate that it also contributes is to briefly highlight this project and transversus abdominus, and the to stabilization of the hip joint and discuss specific strategies for training internal oblique. As psoas passes over assists iliacus with hip flexion. psoas major to contribute to lumbo- the pelvic brim, the fascia of the pelvic stability. posterior fascicles attaches firmly to Evidence of Muscle Dysfunction Based on motor control studies, Summary of Anatomy and the pelvic brim (McVay and Anson, 1940; Williams et al, 1989; Gibbons, Hodges and Richardson (1996, 1997; Physiology see Richardson et al, 1999a) Psoas major has fibrous 1999, 2001, Gibbons et al, 2001).). The nerve supply to psoas is not concluded transversus abdominus was attachments to the anterior aspect of important for spinal stabilization. They all lumbar transverse processes and to reported consistently as most anatomical texts list 3 different identified an anticipatory reaction in the antero-medial aspect of all the transversus abdominus in response to lumbar discs and adjoining bodies variations. These are listed under psoas major, the lumbar plexus and spinal disturbance produced by limb with the exception of the L5-S1 disc movements. In subjects without low (Bogduk et al, 1992; Gibbons, 1999). the femoral nerve. Dissection has shown that the anterior and posterior back pain transversus abdominus was For their relative positions on the activated prior to limb movements and spine, the attachments on the fascicles have a separate nerve supply. The posterior fascicles are supplied by spinal disturbance, while activation of transverse processes were named transversus abdominus was posterior and those on the discs and the ventral rami of spinal nerves T12 through L4. The anterior fascicles are significantly delayed in subjects with bodies called anterior. These low back pain independent of the www.orthodiv.org January/February 2002 - Orthopaedic Division Review 9 direction of limb movements and on the ipsilateral side. In a single case summated to the respiratory action of spinal disturbance. The delayed onset study, the width was decreased in the the diaphragm. This may occur, of contraction of transversus posterior fascicles at the level and however psoas is ideally located to abdominus indicates a deficit of motor ipsilateral to the site of symptoms in assist in a stability role here. Through control and as a result of this the acute low back pain (Whelan and its segmental attachments, axial authors hypothesize there would be Gibbons, submitted). More research is compression and links to the inefficient muscular stabilization of the currently in progress in this area. diaphragm and pelvic floor, psoas may spine. This is a similar pattern of inefficient play a role in spinal stability and There is evidence of lumbar normal low threshold recruitment should now be considered as an multifidus muscle wasting ipsilateral to (previously referred to as inhibition) as important stabilizer of the lumbar symptoms in patients with acute / seen in the deep segmental fibres of spine. subacute low back pain (Hides et al, lumbar multifidus (Hides et al, 1994). Two previous classification systems 1994; Kader et al, 2001). Hides et al This implicates psoas as having a local of muscle function were combined to (1994) used real-time ultrasound to stabilizing role in the lumbar spine develop a new model (Mottram and assess the multifidus muscle. The (Gibbons, 1999; Gibbons et al, 2001; Comerford, 1998; Comerford and paraspinal muscles were scanned in Comerford and Mottram, 2000). Mottram, 2000; 2001). This divides normal subjects and in patients with Further motor control studies are in muscles into local stabilizers, global acute unilateral low back pain. progress to investigate a possible stabilizers and global mobilizers. Psoas Significant asymmetry of multifidus anticipatory timing pattern of psoas as major should be classified as a local cross sectional area (CSA) was noted seen in other local stability muscles. and global stabilizer. The posterior in subjects with low back pain. Model of Psoas Major Function fascicles are ideally suited to perform a This decrease in size of multifidus From dissection studies and a local stabilizer role while the anterior was seen on the side of the symptoms review of the literature, Gibbons fascicles are better suited to have a with the reduced CSA observed at a (1999) has presented a model of psoas global stabilizer role. single vertebral level suggesting pain major. A common model of lumbar Action: inhibition (now considered a decrease stability shows the musculature The local stability role of psoas is to in normal low threshold recruitment). forming a cylinder. The top of the produce axial compression along its However, while the pain may resolve cylinder is the diaphragm, the bottom line of pull. This has the effect of the dysfunction may persist. Hides et is the pelvic floor and the wall is compressing the vertebral bodies to fix al (1996) found that recovery of formed by the segmentally attaching the spine in neutral alignment while multifidus symmetry was not abdominal and posterior spinal longitudinally pulling the head of the spontaneous after painful symptoms musculature, specifically transversus femur into the acetabulum. This resolved. They observed that recovery abdominus and the segmental fibres of ‘pulling in’ or ‘shortening the leg’ of symmetry was more rapid and more lumbar multifidus (Morris, 1961; action should be localized to the hip complete in patients who received Bartlink, 1957; Richardson et al, and pelvis. There should not be any specific, localized multifidus retraining 1999a). Psoas major has intimate lateral tilt (‘hitching’), anterior or (Hides et al, 1996). Correction of this anatomical attachments to the posterior tilt, or rotation of the pelvis. asymmetry resulted