Lumbar Anatomy PDF

# Lumbar Asst. Prof. Ahmed Elshinnawy ## Anatomy The lumbar spine is made up of the lower five vertebrae. Doctors often refer to these vertebrae as L1 to L5. These five vertebrae line up to give the low back a slight inward curve. The lowest vertebra of the lumbar spine, L5, connects to the top...

# Lumbar Asst. Prof. Ahmed Elshinnawy ## Anatomy The lumbar spine is made up of the lower five vertebrae. Doctors often refer to these vertebrae as L1 to L5. These five vertebrae line up to give the low back a slight inward curve. The lowest vertebra of the lumbar spine, L5, connects to the top of the sacrum, a triangular bone at the base of the spine that fits between the two pelvic bones. Some people have an extra, or sixth, lumbar vertebra. This condition doesn't usually cause any particular problems. ## Body * Massive * Transverse diameter > anterior diameter & height * Supports compressive loads * Pedicles: short and thick and project posterolaterally * Laminae: short and broad * Transverse Process : long, slender; extends horizontally * Accessory processes: small, irregular bony prominences, located on posterior surface of transverse process near its attachment to the pedicle, attachment sites for multifidus. * Spinous process : broad, thick, extends horizontally * Zygapophyseal Articular Processes (facets): superior and inferior; vary in shape and orientation * Vertebral foramen : triangular, larger than thoracic vertebral foramen but smaller than cervical vertebral foramen * Fifth lumbar vertebra is a transitional vertebra: wedge- shaped body * Superior diskal surface area 5% greater, Spinous process is smaller and directed superiorly * Intervertebral Disks * Largest * Collagen fibers of anulus fibrosus are arranged in sheets: lamellae * Concentric rings surrounding nucleus * Resist tensile forces in nearly all directions * Shape: concave posteriorly * Provides greater cross-sectional area of anulus fibrosus posteriorly and hence increased ability to resist tension that occurs with forward bending ## Articulations 1. Interbody Joints: * Capable of translations and tilts in all directions 2. Zygapophyseal articulation * True synovial joints * Fibroadipose meniscoid structures * Facet joint capsule restrains axial rotation * Resistance to anterior shear ## Lumbosacral articulation * 5th lumbar vertebra and 1st sacral segment. * 1st sacral segment is inclined slightly anteriorly and inferiorly, forms an angle with horizontal: lumbosacral angle * Increase in angle : increase in lumbar lordosis * Increase shearing stress at lumbosacral joint ## Ligaments: * Supraspinous ligament * Well developed only in upper lumbar region * Most common termination site - L4 * May terminate at L3 * Intertransverse ligaments are not true ligaments in lumbar area and are replaced by the iliolumbar ligament at L4 * Interspinous ligament has least overall stiffness and joint capsules the highest * Anterior longitudinal ligament is strong and well developed in this region * Posterior Longitudinal Ligament is only a thin ribbon in lumbar region * Iliolumbar Ligaments * Series of bands extend from tips and borders of transverse processes of L4 and L5 to attach bilaterally on iliac crests of pelvis * 3 bands: ventral / anterior dorsal / posterior sacral | Ligaments | Function | |---|---| | Anterior longitudinal lig | Limits extension | | Posterior longitudinal lig | Limits forward flexion | | Ligamentum flavum | Limits forward flexion | | Supraspinous ligament | Limits forward flexion | | Interspinous ligaments | Limit forward flexion | | Intertransverse ligaments | Limit contralateral lateral flexion | | Iliolumbar ligament | Resists anterior sliding of L5 & S1 | ## Muscles of lumbar reigon: * Muscles of lower spine region serve roles of : * Producing and controlling movement of trunk * Stabilizing trunk for motion of lower extremities * Assist in attenuating extensive forces that affect this area ### Posterior Muscles: 1. Erector spinae * Iliocostalis, longissimus spinalis * Each having lumbar portion (pars lumborum) andthoracic portion (pars thoracis) * Primary extensors of lumbar region when acting bilaterally * Acting unilaterally, they are able to laterally flex trunk and contribute to rotation 2. Multifidus * Not truly transverso spinales in lumbar region * Run from dorsal sacrum and ilium in region of PSIS to spinous processes of lumbar vertebrae * Line of pull in lumbar region is more vertical * Greater cross sectional area * Produce lumbar extension * Add compressive loads to posterior aspect of interbody joints. ### Lateral muscles: 1. Quadratus lumborum * Deep to erector spinae and multifidus * Acting bilaterally:frontal plane stabilizer * Also stabilization in horizontal plane * Acting unilaterally, laterally flex spine and control rotational motion * If lateral flexion occurs from erect standing, force of gravity will continue motion, and contralateral quadratus lumborum will control movement by contracting eccentrically. * If the pelvis is free to move, quadratus lumborum will “hike the hip" or laterally tilt pelvis in frontal plane ### Anterior muscles: 1. Rectus abdominis * Prime flexor of trunk * Contained within abdominal fascia; separates rectus abdominis into sections and attaches it to aponeurosis of abdominal wall. * Abdominal fascia also has attachment to aponeurosis of pectoralis major. * These fascial connections transmit forces across midline and around trunk. * Provide stability in a corset type of manner around trunk. 2. Psoas major * Runs from lumbar transverse processes, vertebral bodies of T12 to L4 * Distal tendon merges with that of iliacus. * Flexion of hip * At lumbar spine, buttress forces of iliacus, which, when activated, cause anterior ilial rotation and thus lumbar spine extension * Also provides stability to lumbar spine during hip flexion activities by providing great amounts of lumbar compression during activation * Some anterior shear is also produced when it is activated ## Spinal cord and plexus: * Spinal cord ends at approximately L1-L2 * Bundle of spinal nerves extends downward: cauda equina ## The Lumbar Plexus * Formed by T12–L5nerve roots * Supplies anterior and medial muscles of thigh region * Posterior branches of L2-L4nerve roots form femoral nerve – Quadriceps * Anterior branches form obturator nerve, innervating adductor muscle group ## Blood Supply: * Four paired lumbar arteries that arise directly from posterior aspect of aorta * Venous draining internal and external venous systems into the inferior vena cava ## Kinematics: * Movement available: flexion, extension, lateral flexion, and rotation. * Gliding- anterior to posterior, medial to lateral and torsional * Tilt- anterior to posterior, lateral directions * Distraction and compression ## Lumbar Range of Motion: * Flexion: 50 * Extension: 15 * Axial rotation: 5 * Lateral flexion: 20 ### 1. Lumbar flexion * More limited than extension * Maximum motion at lumbosacral joint * Anterior tilting and gliding of superior vertebra occurs * Increases diameter of intervertebral foramina ### 2. Lumbar Extension * Increase in lumbar lordosis * Posterior tilting, gliding of superior vertebra * Lumbar extension reduces the diameter of intervertebral foramina * Fewer ligaments checks extension * During lumbar extension nucleus pulposus displaces anteriorly ### 3. Lateral Flexion * Superior vertebra laterally tilts, rotates and translates over vertebra below * Annulus fibrosus is compressed on concavity of curve and stretched on convex side * Nucleus pulposus migrate slightly towards convex side of bend ### 4. Spinal Rotation * Rotation causes movement of vertebral arch in opposite direction * Ipsilateral facet joints go for gapping and contralateral facet joints for impaction * Axial rotation to right, between L1 and L2 for instance, occurs as left inferior articular facet of L1 approximates or compresses against left superior articular facet of L2. * Limited due to shape of zygapophyseal joints * Also restricted by tension created in stretched capsule of apophyseal joints and stretched fibres within annulus fibrosus * Amount of rotation available at each vertebral level is affected by position of lumbar spine. * When flexed, ROM in rotation is less than when in neutral position * The posterior anulus fibrosus limit axial rotation when spine is flexed * The largest lateral flexion ROM and axial rotation occurs between L2 and L3 ## Lumbo-pelvic rhythm * Bending forward- lumbar flexion (40°) followed by anterior tilting of pelvis at hip joint (70°) * Return to erect- posterior tilting at pelvis at hips followed by extension of lumbar spine * Integration of motion of pelvis about hip joints with motion of vertebral column: increases ROM available to total column * reduces amount of flexibility required of lumbar region * Hip motion: * eliminates need for full lumbar flexion, * protecting annulus fibrosis and posterior ligaments from being fully lengthened ## Kinetics ### Compression * Lumbar region provides support for weight of upper part of body in static as well as in dynamic situations * Lumbar region must also withstand tremendous compressive loads produced by muscle contraction. * Lumbosacral loads in erect standing posture in range of 0.82 to 1.18 times body weight * During level walking in range of 1.41 to 2.07 times body weight * Changes in position of body will change location of LOG and thus change forces acting on lumbar spine * Lumbar interbody joints share 80% of load, Zygapophyseal facet joints in axial compression share 20% of total load. * This percentage can change with altered mechanics: with increased extension or lordotic, Zygapophyseal joints will assume more of the compressive load. * Also, with degeneration of intervertebral disk, Zygapophyseal joints will assume increased compressive load. ### Shear * In upright standing position, lumbar segments are subjected to anterior shear forces caused by: * Lordotic position * Body weight * Ground reaction forces * Resisted by direct impaction of inferior Zygapophyseal facets of the superior vertebra against superior Zygapophyseal facets of adjacent vertebra below * PLL is most heavily innervated while anterior, sacroiliac, and interspinous ligaments receives nociceptive nerve endings. * The lumbar intervertebral discs are innervated posteriorly by sinuvertebral nerves * Laterally by branches of ventral rami and gray rami communicate. ## Pathomechanics: 1. Exaggerated lordosis * Abnormal exaggeration of lumbar curve * Weakened abdominal muscles * Tight hip flexors, tensor fasciae latae, and deep lumbar extensors * ↑ compressive stress on posterior elements * Predisposing to low back pain 2. Sway back * Increased lordotic curve and kyphosis * Weak : lower abdominals, lower thoracic extensors, hip flexors * Tight : hip extensors, lower lumbar extensors, and upper abdominals 3. Flat back posture * Relative decrease in lumbar lordosis (20°), * COG shifts anterior to lumbar spine and hips ## Pathology: ### 1) The Inter-vertebral Disc * Health of the intervertebral disc maintains the health of the integrity of the mechanics of the spine * Low back pain may be due to: * Aging * Reduces the moisture content in the disc * Reduces overall height * account for 20-25% of the total length of the vertebral column * natural degeneration of the disc * trauma, inter-vertebral discs can be responsible for causing low back pain in many individuals. * Common site: L4-L5 ### Grades: 1. Disc Herniation * A general term used to describe when there is any change in the shape of the annulus 2. Disc protrusion * The nucleus of the disc bulges against an intact annulus 3. Extruded disc * The nucleus of the disc bulges through the annulus however remains within the posterior longitudinal ligament 4. Sequestrated disc * The nucleus of the disc breaks through all barriers and is free within the spinal canal ## Contributing factors to the development of a lumbar disc bulge: Several factors may contribute to the development of a lumbar disc bulge. These need to be assessed and corrected with direction from the treating physiotherapist and may include: * poor core stability * a sedentary lifestyle * being overweight * muscle tightness * muscle weakness * joint stiffness * poor lifting technique * poor posture * a lifestyle involving large amounts of sitting, bending or lifting ## Leg pain caused by a herniated disc: * Usually occurs in only one leg. * May start suddenly or gradually. * May be constant or may come and go (intermittent). * May get worse ("shooting pain") when sneezing, coughing, or straining to pass stools. * May be aggravated by sitting, prolonged standing, and bending or twisting movements. * May be relieved by walking, lying down, and other positions that relax the spine and decrease pressure on the damaged disc. ## 2) Spinal Stenosis <start_of_image>* Narrowing of the spinal canal secondary to degenerative changes or trauma to the lumbar spine. * Facet joint arthrosis and/or hypertrophy * disc bulging * spondylolisthesis * Most common in middle-aged and older males ## 3) Piriformis Syndrome * The sciatic nerve runs through the muscle belly of the piriformis as opposed to underneath it * occurs in approximately 15% of the population * characterized by pain reported deep in the buttocks * may be irritated by sitting ## 4) Spondylolisthesis * condition in which one vertebrae anteriorly glides over another * usually occuring at the L4-L5 and L5-S1 levels * graded through X-ray * measured by the percentage of displacement noted | Grade | % | |---|---| | Grade 1 | 0-25% | | Grade 2 | 25-50% | | Grade 3 | 50-75% | | Grade 4 | 75-100% | * Patient complaints * Chronic midline pain at lumbosacral junction * Pain worsened with activity * Pain alleviated with rest * Pain exacerbated by repetitive extension * Possible reports of radicular symptoms ## 5) Lumbar facet pathology * Subluxation or dislocation of facet, Facet joint syndrome (i.e. inflammation), Degeneration of the facet (i.e., arthritis) * 75 to 80% of population experiences low back pain stemming from mechanical injury to muscles, ligaments, or connective tissue ## 7) Facet joint syndrome * The lumbar zygapophyseal joints are the posterior articular process of the lumbar column. They are formed from the inferior process of upper vertebra and the superior articular process of lower vertebra. They are supplied by the medial branches of the dorsal rami (MBN). These joints have a large amount of free and encapsulated nerve endings that activate nociceptive afferents and that are also modulated by sympathetic efferent fibers. Lumbar zygapophyseal or “facet” joint pain has been estimated to account for up to 30% of Chronic low back pain CLBP cases, with nociception originating in the synovial membrane, hyaline cartilage, bone, or fibrous capsule of the facet joint. * Diagnosis of facet joint syndrome is often difficult and requires a careful clinical assessment and an accurate analysis of radiological exams. Patients usually complain of LBP with or without somatic referral to the legs terminating above the knee, often radiating to the thigh or to the groin. There is no radicular pattern. Back pain tends to be off-center and the pain intensity is worse than the leg pain; pain increases with hyperextension, rotation, lateral bending, and walking uphill. It is exacerbated when waking up from bed or trying to stand after prolonged sitting. Finally, patients often complain of back stiffness, which is typically more evident in the morning. ## Sacroiliac joint pain * Sacroiliac joints (SIJs) are dedicated to providing stable but flexible support for the upper body. SIJs are involved in sacral movement, which additionally directly influences the discs and almost certainly the higher lumbar joints. Its innervation has been reported to be by branches from the L5 dorsal primary ramus and lateral branches of the dorsal sacral rami from S1 to S3. The SIJ is well recognized as a source of pain in many patients who present with CLBP. It is thought that pain could be generated by ligamentous or capsular tension, extraneous compression or shear forces, hypermobility or hypomobility, altered joint mechanics, and myofascial or kinetic chain dysfunction causing inflammation. Intra-articular sources of SIJ pain include osteoarthritis; extra-articular sources include ligamentous sprain. In addition, ligamentous, tendinous, or fascial attachment and other cumulative soft tissue injuries that may occur posterior to the dorsal aspect of the SIJ may be a source of discomfort. ### Clinical Features * The patient is typically a young and fit adult presenting with sudden onset back pain whilst lifting or stooping. They are unable to straighten up due to severe pain. * From the onset of the injury, the patient may present with: * Backache * Sciatica (characteristic pain in buttocks and lower limb) * Paraesthesia or numbness in lower leg or foot * Muscle weakness * Urinary retention * Backache and sciatica persists after the injury and is typically made worse by coughing or straining. ### Upper lumbar (L1-L2 & L2-L3): * Disc herniation at the L1-L2 and L2-L3 levels are different from those at lower levels of the lumbar spine with regard to clinical characteristics and surgical outcome. Spinal canals are narrower than those of lower levels, which may compromise multiple spinal nerve roots or conus medullaris ### Lower lumbar (L3-L4, L4-L5 &L5-S1) * Depending on the structures involved, different symptoms may be experienced: * Pressure on ligament - Backache * Pressure on dural envelope of nerve root - Sciatica * Compression of nerve root - numbness, parasthesia and muscle weakness * Compression of Cauda equina - urinary retention (Rare, but it is a medical emergency as damage may become irreversible if left untreated for too long ### Assessment: * Sheet + focus on: * On observation: * Sciatic Scoliosis - the patient may stand with a slight list to one side, increased during forward flexion * Range of back movements severely limited in all planes * On Palpation: * Tenderness in the midline of back * Paravertebral muscle spasm ## LUMBAR ### Assessment: * Sheet + focus on ### Lumbar special tests: 1. Straight leg raising test (Lasegue's sign): * Ask pat to raise one leg if there is pain at: * 15:30 degree → sciatica. * 30: 60 degree → shortening of hamstrings. 2. Well test (Cross straight leg raising): * Raise sound leg, ask pat if feel pain in affected → sciatica. 3. Kering sign: * From fowler position, supine flexion hip and knee 90 degree in affected leg extend the flexed knee → pain → sciatica. 4. Kering test: * Supine lying with both hands behind head, ask pat to flex neck to see his feet → pain → disc prolapsed. 5. Forward bending test (Narei's test): * To assess sciatica, ask pat to lean forward from standing position, if there is sciatica, sever pain, scoliosis toward affected side and pat will flex affected leg. 6. Quick test for sciatica: * Ask pat to walk on his heel → pain in back →L4, 5 * Ask pat to walk on his toes → pain in back →S1 7. Ely's test: * From prone lying position, extend pat leg, if there is pain in anterior aspect of thigh → femoralgia. 8. Spring test: * To detect spasm in Para spinal ms. from prone lying, two palm and compress Para spinal if there is hardness in ms. → spasm. 9. Quadrant test: * To assess mobility of spine, from standing ask pat to try to touch opposite popliteal fossa. 10. Patrick test (Faber test): * For assess sacroiliac joint strain. Affected leg flex, abd, external rotation as ankle on opposite knee, then press on flexed knee and opposite A.S.I.S → pain 11. Pelvic rocking test: * For assess sacroiliac joint strain, rock pelvic by both hands toward midline, if there is pain. 12. Gaenslen's sign: * For assess sacroiliac pain, pat make full flexion of both legs then let the affected limb to be dropped over edge of bed → pain in back. 13. Slump test: * The patient sits at the end of a table with the arms behind the back and legs together. * The patient slumps as far as possible, producingnfull trunk flexion * If no changes are noted, the examiner asks the patient to extend their knee or passively extends one of the pt's knees, symptoms are assessed * If no changes are noted still, the examiner passively dorsiflexes the pt's anklen with the knee in extension, symptoms are assessed. * Neck flexion is then added to assess symptoms, then released to see if symptoms subside. This is to be performed on bilateral LE's ## Dermatome of lumbar: * L1 → upper 1/3 front of thigh. * L2→ middle1/3 front of thigh. * L3 → lower 1/3 front of thigh. * L4 → Anterolateral aspect of thigh, front of knee. Anteromedial aspect of leg, medial aspect foot and big toe. * L5 → Lateral aspect of thigh, lateral aspect of leg, middle 1/3 of dorsum of foot and middle 3 toes. * S1 → posterolateral aspect thigh and leg, lateral foot and little toe. * S2 → Posterior aspect of thigh, leg and sole of foot. * S3, 4, 5 → saddle shape area around anus. ## Myotome of lumbar: * L1 → Not included. * L2 → Hip flexor. * L3 → Knee extensor. * L4 → Dorsiflexion of ankle. * L5 → Dorsiflexion of toes. * S1 → Planter flexion ankle. * S2 → Knee flexion. * S3, 4, 5 → anal and perineal ms. ## Treatment: ### 1. Acute Stage: * a. Rest: * 3-4 weeks on hard mattress. Rest is complete but not absolute (patient can go to w.c.) * Patient without radiated pain → prone lying for 2 weeks * Patient with radiated pain → side lying with hips and knees flexed for 2 Weeks or fowler's position. * b. Plaster Jacket: For business man * c. Continuous (fixed) lumbar traction: For 2-3 weeks * d. Light lumbar support (or corset): * For 3 months. * e. Starting program of weight reduction: ### 2. Physiotherapy after acute stage: * a. Source of heat (deep followed by superficial) * Deep heat → Ultrasound → continuous, on back + affected nerve root and for 5 cm. * Superficial heat → Hot packs → moist, preferable and for 20 min I.R → Dry * Using superficial heat before deep one will cause vasodilatation of superficial circulation and so decrease effect of the followed deep heat. * b. Pain killing electrical stimulation: * Local LBP → Interferential * Referred pain → TENS on the course of affected nerve. * 20-30 min * c. Lumbar traction: * Mechanical or electrical lumbar traction. * Time 15 min. * Weight → more than 50% of body weight. * Position crock lying, fowler or prone lying. * d. Postroanterior central manipulation: * To push the posterior prolapsed disc forwards. * e. Exercise: * Graduated back exercise start only after disappearance of radiated pain. They start by passive back extension from prone position, then raising head, head and arms from prone lying, then bridging exercise, then alternative hyperextension of both legs from prone lying starting by sound one. * Lateral flexion trunk exercise from crock lying. If scoliosis still present. * Strengthening exercise for weak lower legs. * In mild cases static and lower abdominal exercises * f. Advises: * Wearing lumbar support in moderate and sever cases. * Hot packs on back and gluteal region. * Avoid source that increase intradiscal pressure. I.e. abdominal exercise, coughing and sneezing. * Avoid high heel in females. * Avoid intramuscular injection of the affected gluteal region. * Avoid forward bending and rotatory activities. * Teach the patient the proper way of standing up from supine by turning side lying on the sound side firstly then bends both hips and knees followed by pushing bed by the upper hand to sit up then stand up. * Continue in back exercise. * Avoid weight gain. * Avoid changes in temperature. ### 3. Post-operative disc prolapse physiotherapy: * a. Early (from 1 day post-operative) physiotherapy: * TENS →20-30 min, to decrease pain. * Breathing and circulatory exercise. * Ambulation: patient lies prone firstly and then stands by supporting on his hands to stand up on his legs. Return to bed in opposite sequence. * b. Late treatment (before removal of sutures): * Static back exercise from 6th day post-operative. * Knee exercise, hip abduction, adduction and static extension exercise. * c. Late treatment (after removal of sutures): * Ultrasound to break down adhesion. * Manual deep friction massage. * Graduated back exercise. * Static abdominal exercise. * Dynamic hip extension exercise and hip flexion with knee flexion. * d. Late treatment (after 1-1.5 months): * Graduated dynamic abdominal exercise. * e. Advises: * Continue back exercise. * Avoid carrying weight. * Avoid weight Gain.