SELECTED OSTEOPATHIC TECHNIQUES IN CHRONIC LUMBAR DYSFUNCTION

Transcription

1 SELECTED OSTEOPATHIC TECHNIQUES IN CHRONIC LUMBAR DYSFUNCTION Thesis Submitted to Basic Science Department in Partial Fulfillment for the Requirements of Doctoral Degree in Physical Therapy Prof. Dr. Fatma Seddek Amin Professor of Physical Therapy Department of Basic Science Faculty of Physical Therapy- Cairo University NISREEN AHMED ABD El-GALIL M.sc in Physical Therapy (2007) Supervisors Prof. Dr. Yasser Hassan El-Miligue Professor of Orthopedic Surgery Orthopedic Surgery Department Faculty of medicine Cairo University Dr. Marzouk Abd El-Fattah El-Lythy Lecturer of Physical Therapy Department of Basic Sciences Faculty of Physical Therapy Cairo University Faculty of Physical Therapy Cairo University 2012

2 CHAPTER II LITERATURE REVIEW This chapter is organized in the following order: A) Anatomical basics of back, B) Biomechanical consideration C) functional anatomy D) Back pain, chronic lumbar dysfunction, E) Mechanical disorders of the lumbar spine F) Pathophysiology of LBP, G) Somatic dysfunction and Movement pattern abnormalities H)Fascial consideration I) Effect of mechanical stress on connective Tissue J) Back ground of osteopathic techniques), K) Muscle energy technique, L)Myofascial techniques M) Evaluation of lumbar dysfunction. A) Anatomical Basics of back: The Vertebral Column The vertebral column is not a single bone, Rather it is a stack of (33) bones that are flexibly connected one above the other. It is unique and amazing structure, in lay terms, it is called the back bone. The vertebral column is strong enough to support several hundred weights, yet pliant and elastic furnished with levers of muscles by which it is bent in every direction. This column certainly combines the most apposite qualities and performs functions apparently incompatible (Richard, 2004). The vertebral column is made up of a series of separate bones, the vertebrae, linked together by cartilages, discs and ligaments. Altogether, the column consists of 33 vertebrae and 23 intervertebral discs which are generally grouped into five divisions: 7 cervical vertebrae (neck), 12 thoracic vertebrae (rib cage area), 5 lumbar vertebrae (lower back), 5 sacral vertebrae (base of the spine) and 4 coccgeal vertebrae (tail bone)(grobowski, 2003). The functional unit of the vertebral column, the motion segment, is similar in structure through the entire spinal column except, for the first two cervical vertebrae. The motion segment consists of two adjacent vertebrae and a disc that separate them. In each motion segment the ROM is only a few degrees, but in combination, the trunk 8

3 is capable of moving through considerable ROM. The functional spinal unit (FSU) has been divided into two groups according to the structures that compose each-the anterior elements and the posterior elements. The anterior elements include the posterior longitudinal ligament and all the anatomical structures in front of it. Posterior elements include all those structures located posterior to the posterior longitudinal ligament(hamill and Knutzen, 2003).. Figure (1): the vertebral column: (A) Lateral side (B) Posterior aspect (Adapted from Porterifield J et al., Mechanical low back pain, prescriptive in functional anatomy, 1998) The Lumbar spine: The lumbar vertebrae, along with their articulation and intervertebral foramin offer distinct characteristics that have significant biomechanical influences. The lumbar spine is composed of five segmented vertebrae (Richard S, 2004). The vertebral body consists of spongy bone covered by a thin shell size of the vertebral bodies increase from the first lumber to the fifth. The pedicels are two short stout bony projections from the postero-lateral aspects of the vertebral body because most of the musculature of the lumbar spine attaches to the various posterior processes of the vertebrae. The force of the muscle contraction is ultimately transmitted to the vertebral body through the pedicle (Grobowski T, 2003). 9

4 The paired laminae originate from the posterior aspect of the pedicle. The pares interearticularis is the part of the lamina that lies just superior to the articular surface of the inferior articulating process. This bony structure assists in counter balancing the anterior shear force of the antigravity posture. Above and below the pedicle are the superior and inferior notches. When two lumbar vertebrae come together, they form the intervertebral foramen through which the spinal nerves exits and being divided into anterior and posterior ramie. ( Hamill, 2003 and Ashton Miller,1997). Each lumbar vertebrae figure (2-2) has two superior facets which face superiority and medially and two inferior facets which face anteriorly and laterally. It is important to know that the inferior articulating process lies medial to the superior articling process understanding this anatomic relationship helps the clinician to visualize the forces generated into and through this joint as movement analysis is carried out during assessment process. The correct anatomic term is Zygoapophyseal joint (Richard S, 2004 and Grobowski, 2003). Fig (2-2) Lumbar Vertebra (A) Side View, (B) Superior View. (Adapted from: Magee, 2006) The Intervertebral disks: The disks made up approximately one quarter of the total length of the vertebral column. They function chiefly as hydraulic shock absorbers that permit compression and distortion. Therefore, they are motion between the vertebrae. The extremely important. The amounts of movement that can occur in any region of the vertebral column depend in large part on the ratio between the height of the 10

5 intervertebral disks and the height of the bony part of the column. Disk thickness varies with the region of the spine. The regions from thickest to thinnest are the lumbar (9mm), thoracic (5mm), and cervical (3mm) (Norkin, 1992 and Joseph, 1996). The cervical region is most mobile since its disk to body ratio is 2:5 or 40% In contrast, the lumbar region is slightly less mobile with a ratio of 1:3 or 33%. Hence the disks play a major role in determining the potential ROM in the back. (Alter M, 2004). The disc consists of two parts: the nucleus pulpous and the annulus fibroses. The liquid and elastic properties of them, acting in combination, enable the disc to withstand great loads. The major components of the intervertebral discs are collagen fibers, proteoglycans and water (Norkin et al., and Levangie, 1992). The nucleus pulpous is composed of an incompressible gel-like material that is encased in an elastic container. A protein polysaccaride makes up its chemical composition. The nucleus is strongly hydrophilic, that is, it has a strong affinity to water. In fact, it can bind nine times its volume of water (the imbibing pressure of the nucleus has been found to reach 250 mm Hg). (Grobowski, 2003). When the spine is flexed the disc becomes wedge shaped becoming thinner anteriorly and thicker posterior. This deformation allows the vertebrae to come closer together interiorly and to separate posterior. Thereby ncreasing the flexion curve of the spine. Conversely, during spinal hyperextension, the nucleus became as thinner posterior and thicker anteriorly. This deformation allows the vertebrae to come closer together posteriori and to separate interiorly resulting in increasing the extension curve of the spine. Thus, deformation of the disks enhances spinal mobility. (Hamill, 2003 and Ashton, 1997). The vertebral Ligaments: Ligaments are considered as a passive component providing stability to the spine by resisting separation of the vertebrae and passively balancing the forward flexion bending or movement created by the external load and the body weight Figure(3-2) (Kaigle et al, 1995; Norkin et al, 1992 and Gracovetsky et al, 1986). 1- The Anterior Longitudinal Ligament It is a broad and strong band of fibers which extends along the anterior surfaces of the vertebral bodies from the axis to the sacrum, figure (3). It is broader 11

6 below than above, thicker in the thoracic than in the cervical and lumbar regions, and somewhat thicker opposite the bodies of the vertebrae than opposite the intervertebral fibro-cartilages (Larsen, 2002). 2- The Posterior Longitudinal Ligament: It is situated within the vertebral canal, and extends along the posterior surfaces of the vertebral bodies, from the body of the axis to the sacrum. It is broader above than below, and thicker in the thoracic than in the cervical and lumbar regions. It is denser and more compact than the anterior ligament (Larsen, 2002 and Gray, 1977). 3- Ligamenta Flava: Ligamenta flava connect the laminae of adjacent vertebrae, from the axis to the first segment of the sacrum. Each ligament consists of two lateral portions which commence one on either side of the roots of the articular processes, and extend backward to the point where the laminae meet to form the spinous process. In the cervical region the ligaments are thin, but broad and long; they are thicker in the thoracic region, and thickest in the lumbar region (Larsen, 2002 and Gray, 1977). 4- The Supraspinal Ligament It is a strong fibrous cord which connects together the apices of the spinous processes from C7 to the sacrum. It is thicker and broader in the lumbar than in the thoracic region, and intimately blended with the neighboring fascia. It is continues upward to the external occipital protuberance and the nuchal line as the ligamentum nuchæ (Gray, 1977). 5- The Interspinal Ligaments They are thin membranous ligaments that connect adjoining spinous processes and extend from the root to the apex of each process. They meet the ligamentaflava in front and the supraspinal ligament behind. They are narrow and elongated in the thoracic region; broader and thicker in the lumbar region; and slightly developed in the neck (Gray, 1977). 6- The Intertransverse Ligaments They are interposed between the transverse processes. In the cervical region they consist of a few irregular fibers; in the thoracic region they are rounded cords 12

7 w connected with the deep muscles of the back; and in the lumbar region they are thin and membranous (Larsen, 2002). 7- Illiolumbar ligament: (illiotransverse ligament): It connects the illium to the transverse processes of the fourth and fifth lumbar vertebrae with the lower band running from the inferior aspect of L 5 transverse processes to the anterior portion of the sacral ala which is often termed lumbosacral ligament (Warwick and Williams, 1980). Fig (2-3)The ligaments of the vertebral column (Adaptedd from: Larsen, 2002) Back muscles: 1 Back Extensors: There are numerous small muscles constituting the extensor muscle group, however, they can be classified into two groups: erector spinae (sacrospinalis) and deep posterior or paravertebral (transverse spinalis) muscles. These muscles run the spinal column in pairs with either long muscle fiber, extending from sacrum to thorax, or short muscle fibers, only span one, two, or three vertebrae. Functionally if these muscles are activated bilaterally, they will createe extension, while creating rotation or lateral flexion if activated unilaterally (Hamill, 1995, Tyldesley and Grieve, 1996). 13

8 Fig (2-4) Muscles of the posterior spine adapted from Oatis, 2004) A) Erector Spinae Muscles (Sacrospinalis): It is the largest muscle of the back in the lumbar region and plays acrucial role in the dynamic stability and mobility of the lumbar spine. It is a common muscle mass that arises in the lumbosacral region from the erector aponeurosis and inserts into the lumbar and thoracic transverse processes and ribs (Macintosh and Bogduk, 1991). Traditionally erector spinae consists of iliocostalis, longissimus and spinalis(carmichael and Burkart, 1979). For the ease of description, it will be referred to as superficial and deep erector spinae. I- Superficial Erector Spinae: It is attached to the erector spinaeaponeurosis and iliac crest then ascends upwards to attach to the ribs. It creates an extension moment over the lumbar spine and pulls the thorax posterior when it contracts concentrically. It functions as eccentrically to control the forward trunk bending, and isometrically to control the position of the lower thorax with respect to the pelvis during movement (Porterfield and Derosa, 1998). 14

9 Fig (2-5) The three groups of erector spinae adapted from Oatis 2004 II- Deep Erector Spinae: It originates from the illium, above and lateral to the posterior superior iliac spine, and from the undersurface of the erector spinaeaponeurosis, then it ascends to be attached to the lumbar transverse processes (Norkin and Levangie, 1992). It creates a stabilizing moments for the lumbar spine against the anterior shear of the gravitational force. Contraction of deep erector spinae and contralateral psoas major muscle will create guy wire stabilization for the lumbar spine in weight bearing postures, thus renders the lumbar joints more resistant to various forces in sagittal plane (Porterfield and Derosa,1998). B) Transverse Spinal Muscle Group: This group commonly comprises (from superficial to deep): the semispinalis, the multifidi, the rotators, interspinalis and intertransversari. These muscles run up and down the spinal column in pairs and attach to the transverse, spinous and articular processes of the vertebrae, and create extension if activated bilaterally while creating rotation or lateral flexion if activated unilaterally (Norkin and Levangie, 1992).. The superficial muscles of the transverse spinal group are accepted as semispinalis in the upper spine, while multifidi exist as superficial and well-developed muscle in lumbar spine where the semispinalis is absent (Basmajian, 1979).. Because of their attachment to each vertebra, they are responsible for proprioceptive input to the central nervous system, as they are continually placed 15

10 under various tensile or compressive loads with trunk activities (Porterfield and Derosa, 1998). Beside the stabilizing functions of the multifidus, its attachment in the spinous processes of the lumbar vertebrae will make it able to create an extension moment over the lumbar vertebral segments (Bogduk and Tomy, 1987). Fig (2-6) Transversospinalis muscles (Adapted from Oatis 2004). 2. Trunk Flexors One of the key muscle groups contributing to mobility and stability of the lumbar spine and pelvis is the abdominal mechanism. The muscles of the abdominal wall are region specific and do not run the length of the column as the extensor group muscles do. The abdominal wall consists of external abdominal oblique, internal abdominal oblique, transverses abdominus and rectus abdominus muscles (Porterfield, 1985). 16

11 . Fig (2-7)Abdominal muscles(adapted from McGill 2004). a) Rectus Abdominus: Rectus abdominus is situated on the anterior surface of the abdomen on either sides of the linea alba. It is a powerful stab like muscle arising from the lower end of sternum and costal cartilages of the fifth, sixth and seventh ribs and passing vertically down. The muscles insert in the pubis from the front of the symphysis pubis to the pubic tubercle laterally (Gray, 1977 and Larsen, 2002). b) External Abdominal Oblique: It is the largest and most superficial antero- lateral muscle in the abdominal wall, originates by fleshy digitations of the last eight ribs and extends inferiorly to insert into the iliac crest, and inferiorly and medially to blend with the abdominal aponeurosis (Palastanga et al., 1994). c) Internal Abdominal Oblique: It lies deep to the external abdominal oblique and is attached to the iliac crest and lateral raphe of the thoracolumbar fascia. The muscle fibers pass upwards and inwards to be inserted into the lower ribs and the abdominal aponeurosis (Larsen, 2002).. d) Transversus Abdominus: It is located deep to the internal abdominal oblique muscle and is attached to the lateral one-third of the inguinal ligament and the iliac crest and shares with internal abdominal oblique its attachment from the lateral raphe of thoracolumbar fascia. Fibers then will pass horizontally and attach to the abdominal aponeurosis (Grobowski, 2003).. Thoracolumbar fascia (TLF): 17

12 Anatomically, TLF consists of three layers (Fig. 2-8). The anterior and middle layers arise from the transverse processes of the lumbar vertebrae and join together laterally, encompassing the quadrates lumborum while blending with the fascia of the transverses abdominis and internal oblique abdominis muscles. This creates a direct connection between the bony spine and the deep abdominal muscles and appears to be an important relationship for the dynamic stabilization of the lumbar spine (Beattie 2004). The large posterior layer of the TLF arises from the spinous processes of the thoracic, lumbar and sacral vertebrae and covers the erector spinae muscles. Laterally, it blends with the latissimus dorsi muscle, and inferiorly it blends with the gluteus maximus muscle, thus forming a direct connection between the proximal humerus (the distal attachment of the latissimus dorsi muscle) and the proximal femur (the distal attachment of the gluteus maximus muscle) (Gracovetsky 1986). One of the important functions of the TLF occurs when one in the position of lumbar forward bending, with the hips and knees slightly flexed, while pulling an object upward away from the ground. This requires activity of the gluteus maximus, lumbar erector spinae, abdominal muscles and latissimus dorsi, all of which have centeral attachments to the TLF. The TLF is then strongly tensed, providing stability to the posterior aspect of the lumbar spine as it reinforces the posterior ligaments and muscular system (Vleeming et al, 1995). Fig. (2-8):Thoracolumbar fascia. A. Posterior view. B. Transverse view (Adapted from Beattie 2004). The Spinal Nerves: 18

13 The spinal nerves consist of ventral and dorsal roots that leave and enter the spinal cord, respectively. The ventral roots contain axons of motor neurons from the anterior gray horn of the spinal cord. The dorsal roots contain sensory axons that arise from the sensory cell bodies contained in ganglia, which are the enlargement of the dorsal roots. There are 11 pairs of spinal nerves in the lumbar sacral and coccygeal, including 5 lumbar, 5 sacral and 1 coccygeal. The spinal nerves emerge below the corresponding vertebrae in the lumbosacral region. The spinal nerves exiting from the spinal canal are close to the medio-inferior border of the upper pedicle and lie in the upper portion of the intervertebral foramina in the lumbar spine. Most ganglia of the lumbar spinal nerves lie within the intervertebral foramen (Rauschining, 1987). After exiting from the intervertebral foramina, each spinal nerve divides into a small dorsal ramus and a large ventral ramus. The dorsal rami courses posteriorly to supply the spinal ligaments, muscles and skin of the back. The ventral rami are longer, and run in infero-lateral direction in the lumbar region to form the lumbar and sacral plexuses (Hesegawa et al, 1996). B- Bio-mechanical Consideration: The ability of the human to maintain normal posture and to balance external loads applied to the trunk and the upper limbs relies on the contraction and relaxation of a large number of muscles. The involved muscles balance the spinal column and maintain the overall mechanical integrity of the trunk (Ladin et al., 1989). The increased size of the lumbar vertebral bodies and discs in comparison to their counterparts helps the lumbar structures to support the additional weight. In erect posture the line of gravity passes through the combined axis for the lumbar vertebrae so no net torque exists. Any deviation of the line of gravity will lead to torque production (Norkinand Levangie, 1992).. A) Mobility: 19

14 The movements of the spine are limited by various ligaments attached to the vertebrae, the position of the articular facets, the shape and slant of the spinous processes, and relative sizes of the intervertebral discs (Adams et al, 1994). In the lumbar region the large intervertebral disks and the posterior direction of the spinous processes allow more free sagittal motion, and frontal motion, so that the upper portion of the trunk can be circumducted by the movement in the lumbar region. Rotation in the lumbar region is always limited as the articular processes soon Lock together (Adams and Dolan, 1995). Flexion is relatively free in the lumbar region having a total range of fifty-five degree, while extension a range of thirty degree. The range of lateral flexion varies with age, during the pre-teenage years the range may be as large as sixty degree on each side of the midline and by age of thirty this have been halved Rotation in the lumbar region is extremely small. Being of only few degrees (Palastanga et al, 1991) B) Stability: The stabilizing system of the spine must limit the excursion of spinal motion segments and maintain the proper ratio of neutral to elastic zone motion (Panjabi, 1992) The stabilizing system of the spine consists of three subsystems: 1. The Passive Subsystem: The passive subsystem consists primarily of the vertebral bodies, zygapophyseal joints and joint capsules, spinal ligaments, and passive tension from the musculotendinous units. They are sense changes in position and providing feedback to the neural control subsystem through afferent nerve fibers that are capable of conveying aproprioceptive input to the higher centers (Panajabi, 1992). 2. The Active Subsystem: 20

15 The active subsystem of the spinal stabilizing system consists of the spinal muscles and tendons. The active and neural subsystems are primarily responsible for spinal stability in the neutral zone (Panjabi, 1992).. These muscles are lumbar multifidus, transverses abdominis and posterior fibers of internal oblique muscles and posterior fasciculus of psoas. Dysfunction of the local system results in motor control deficit associated with delayed timing, or recruitment deficiency. These muscles react to pain and pathology with inhibited firing patterns (Hodges and Richardson, 1997).. This delay in recruitment results in decreased muscle stiffness and poor spinal segmental control (Emerson, 2001).They usually cross over only one spinal segment. They work at low load and do not produce movement. Activity of the local stability system is independent of direction of movement. When these muscles are in dysfunction, there is usually a reaction to pain and a painful spasm is produced (Dolfan, 1998). The lumbar multifidus, figure (2-9) is considered to have the greatest potential to provide dynamic control to the motion segments. This muscle originates from the spinous processes of the lumbar vertebrae forming a series of repeated fascicles that attach to the inferior lumbar transverse processes, ilium, and the sacrum. The force vectors of the multifidi indicate that they can generate posterior rotation in a sagittal plan, because contraction of the abdominal oblique muscles results in combined motion into flexion and rotation, the multifidi are recruited to co-contract with the internal oblique, counter balancing the forward shear forces, stabilizing the segment, and allowing pure axial rotation. Thus, the multifidi are effective as stabilizers, can balance shear forces, and seemingly produce, rotation, although not as prime rotators. The multifidus also secondarily maintain the lumbar lordosis by the nature of the force vector posterior to the vertical bodies (Weinsteing et al., 1998). 21

16 Fig. (2-9): Multifidus Muscle (adapted from: adapted from: Virginia Cantarella 1999) The abdominals have been proposed to play an important role in generating extensor force during lifting tasks, either by increasing intra abdominal pressure or by creating tension in the lumbodorsal fascia (Gracovetsky et al, 1985). The oblique abdominal and trasversus abdominal muscles, figure (2-10), with their more horizontal orientation, are thought to contribute to spinal stability by creating a rigid cylinder around the spine through its circumferential orientation and by increasing the stiffness of the lumbar spine through creating an extensor moment via the thoracolumbar fascia, and through increasing the intra-abdominal pressure (Hodge and Richardson, 1997).. Fig. (2-10): Transverses Abdominis Muscle (adapted from: Virginia Cantarella 1999). 22

17 The stability of the lumbar spine is determined by osteoligamentous structures and trunk muscles. Because motion takes place in all three dimensions simultaneously, complex loading patterns act on the passive structures of osteoligamentous spine and, if unprotected, the lumbar spine is vulnerable to being damaged. Therefore, it is essential that the motions are precisely controlled by lumbar and abdominal muscles to produce the stiffness required to optimize the loading on the lumbar spine, and to prevent overload injury (McGill, 1997). The multifidus muscles are the most important back extensor muscles involved in providing the required stiffness of the lumbar spine. Spinal stability is additionally increased with trunk flexor-extensor muscle co-activation, which increases intra-abdominal pressure and produces abdominal spring force. Although all trunk muscles may participate in stabilizing the spine, transverses abdominis and multifidus muscles are thought to be the most important in this respect (Rishardson, 1999). 3- The Neural Control Subsystem: The neural control subsystem is thought to receive input from the structures of the passive and active subsystems in order to determine the specific requirements for maintaining spinal stability, then acting through the spinal musculature to stabilize the spine (Hodge and Richardson, 1997). Dysfunction in the neural control subsystem may place other spinal structures at risk for injury (Panjabi, 1992).. C) Functional Anatomy: The normal function of the lower back has been investigated in different studies. These functions include: 1- Transfer of body weight and bending moment of the head and trunk to the pelvis. 2-It allows sufficient physiological motion between the trunk and lower extremities through its articulating surfaces. 3-Protection of delicate neural structure from potentially damaging forces or motion produced by sudden movements (white, Panjabi, 1978). When axial loud is applied to the disc, it tends to lose water and absorb sodium and potassium until its internal electrolyte concentration is sufficient to prevent further loss of water. 23

18 When this chemical equilibrium is achieved, intradiscal pressure becomes equal to external pressure. The intermittent changes in the disc pressure during different body posture help in pumping action of the disc and water movement in and out of the disc that transport nutrition and flushing out metabolic waste products from the disc (Coste and Derosa, 1991). The basic part of the functional unit of the vertebral column is the apophyseal joint; this joint is typically synovial joint. The attachment of its capsule, associated ligament and the curvature of its articular surface provide mobility in the longitudinal plane and stability in transverse plane (Coste and Derosa, 1991) So the apophyseal joint allow free movement in flexion and extension direction and limit the movement in the rotatory direction due to its anatomical alignment (Portrifield and Derosa,1999).. Further stability of the spine is provided by the osteoligamentous structures, which reinforce the outer layers of the intervertebral disc. These fibroligamentous bands vary in size and shape alongside the length of the spine (Cailliet R, 1994). Among these ligaments the powerful anterior and posterior longitudinal ligaments that provide stability due to connection of the vertebral bodies in the cervical, lumbar and thoracic region (White and Panjabi, 1978). The major important spinal ligament is the ligamentum flavum that connecting the lamina of the adjacent vertebra so provide greater stability for the spine. Although most spinal ligaments are composed primarily of collagen fibers, the ligamintum flavum contains high proportion of elastic fibers which make the ligament in tension even when the spine is in anatomical position. This tension helps in providing constant support for the intervertebral disc (Coste and Derosa, 1991). More over the strength of the ligament is proportionally related to its cross sectional area. The ligament with greater cross sectional area provides greater stability and less displacement when the spine is subjected to physiological load (White and Panjabi, 1978). Other researchers estimated that the ligaments can fail at lower strain when they are loaded rapidly. Thus posture changes may be perfectly saved during normal movement but it could be damaging if it was imposed to the body too suddenly (Wood, 1979). 24

19 For basic understanding of extrinsic stability of the spine, it is helpful to visualize the roles of back muscles; these muscles were originally segmental and extending from one vertebra to the next. The musculature of the back is formed by incompletely separated layers of muscles, distinguishable in part by the direction of their fibers and in part by their length (Shead, 1976). The chief function of the back muscles is mainly to resist the gravity when one assumes the erect posture. Regardless of what muscles start the movement, once the vertebral column is bent far enough laterally or forward to allow gravity to become an important factor, the muscles of the back resist this movement. It must actively contract in order to prevent falling and to make the movement smooth and controlled. (Donatelli and Wooden, 1989). The security of the spine depends greatly on the protective response of paraspinal and abdominal muscles to posture and movement. The abdominal muscles play an important role in supporting the spine partly by producing sufficient intra abdominal pressure to splint the anterior and lateral aspect of vertebral column, partly by their attachment to lumbar fascia and partly by a load carrier. The frequency of muscle injury as a source of low back pain is debatable, but there is no doubt that abdominal and spinal muscles are important component of proper spinal function (Porter, 1993). D-Back pain: Low back pain (LBP) is defined as pain and discomfort, localized below the costal margin and above the inferior gluteal folds, with or without leg pain. Nonspecific (common) LBP is defined as low back pain not attributed to recognizable, known specific pathology (e.g. infection, tumor, osteoporosis, ankylosing spondylitis, fracture, inflammatory process, radicular syndrome or cauda equina syndrome). Acute LBP is usually defined as the duration of an episode of low back pain persisting for less than 6 weeks; sub-acute low back pain as LBP persisting between 6 and 12 weeks; chronic LBP as low back pain persisting for 12 weeks or more. Low back pain is one of the most common symptoms evaluated and treated by primary care physicians (Canoso, 1997 and Deyo, 1998). The common cold is the 25

20 only medical illness associated with more lost days from work than back disorders (Frymoyer, 1988). In any 12-month period in the United States (U.S), 15% to 20% of the population has an episode of lumbosacral pain. Furthermore, back symptoms occur in 50% of working age adults yearly, and 2% of the U.S population is either temporarily or chronically disabled because of back problems at any given time (Bigos et al., 1994). Low back pain is a symptom that is associated with a wide range of clinical disorders (Borenstein et al., 1995). Although for all practical purposes the causes are "mechanical disorders". Mechanical disorders of the lumbosacral spine cause more than 90% of all episodes of back pain (Nachemson A, 1976). These patients most often have no definable cause of their back pain, which is attributed to muscle or ligamentous "strain or injury" or facet joint arthritis. Less often disc herniation or spinal stenosis may cause the pain. Mechanical disorders are characterized by exacerbation (sustained spinal extension) and alleviation (supine position) in direct correlation with particular physical activities. The remaining 10% of adults with back pain have the symptom as a manifestation of a systemic illness, such as cancer, inflammatory back disease, or infection. Occasionally, back pain is referred from intra abdominal or intrapelvic pathology. A systematic approach to the diseases, based on a classification scheme, helps organize the diagnostic and therapeutic options available to the clinician responsible for these patients (Borenestein, 1998). Chronic lumbar dysfunction: The term lumbar dysfunction refers to non-specific low back pain, which is defined as low back pain that does not have a specified physical cause, such as nerve root compression (the radicular syndrome), trauma, infection or the presence of tumor. This is the case in about 90% of all low back pain patients (Zeevir Dvir, 2003). Chronic low back dysfunction (CLBD) is a label for a group of disorders. The causes and symptoms vary from patient to patient. Men and women are affected equally. Low back pain (LBP) is its key feature. It is a symptom rather than a disease 26