Chapter 25 Lumbar Spine

Overview At some time in their lives, 80% of the general population will experience some type of low back pain (LBP) - it is second only to the common cold as a reason for physician visits, and the most expensive source of compensated work related injury in modern industrialized countries Despite the frequency of LBP and the many studies examining LBP, LBP is a difficult problem to investigate and several key issues concerning its occurrence, natural history and prognosis remain unanswered

Anatomy The lumbar spine consists of 5 lumbar vertebrae Between each of the lumbar vertebrae is the intervertebral disc (IVD) The articulations between two consecutive lumbar vertebrae form three joints One joint is formed between the two vertebral bodies and the intervertebral disc (IVD) The other two joints are formed by the articulation of the superior articular process of one vertebra and the inferior articular processes of the vertebra above.

Anatomy Vertebra In general, the lumbar vertebrae increase in size from L 1 to L 5 in order to accommodate progressively increasing loads

Anatomy The Zygapophyseal Joint In the intact lumbar vertebral column, the primary function of the zygapophyseal joint is to protect the motion segment from anterior shear forces, excessive rotation, and flexion

Anatomy Ligaments Anterior longitudinal ligament (ALL) Extends from the sacrum along the anterior aspect of the entire spinal column, becoming thinner as it ascends Posterior longitudinal ligament (PLL) Found throughout the spinal column, where it covers the posterior aspect of the centrum and IVD

Anatomy Ligaments Ligamentum flavum (LF) Interspinous ligament Connects two consecutive laminae Interspinous ligament Connects two consecutive spinal processes Supraspinous Ligament Connects the tips of two adjacent spinous processes

Anatomy Ligaments Iliolumbar Ligament Pseudo ligaments Functions to restrain flexion, extension, axial rotation, and side bending of L‑5 on S‑1 Pseudo ligaments These ligaments, the intertransverse, transforaminal, and mamillo-accessory, resemble the membranous part of the fascial system separating paravertebral compartments, and do not have any mechanical function

Anatomy Muscles Quadratus Lumborum Lumbar multifidus (LM) The importance of this muscle from a rehabilitation viewpoint is its contribution as a lumbar spine stabilizer Lumbar multifidus (LM) The lumbar multifidus is an important muscle for lumbar segmental stability through its ability to provide segmental stiffness and control motion

Anatomy Muscles Erector spinae The erector spinae is a composite muscle consisting of the iliocostalis lumborum and the thoracic longissimus. Both of these muscles are subdivided into the lumbar and thoracic longissimii and iliocostallii

Anatomy Muscles Thoracolumbar fascia (TLF) Assists the in transmission of extension forces during lifting activities Stabilizes the spine against anterior shear and flexion moments

Anatomy Nerve Supply The nerve supply to the lumbar spine follows a general pattern The outer half of the IVD is innervated by the sinuvertebral nerve and the grey rami communicants, with the posterior-lateral aspect being innervated by both the sinuvertebral nerve and the grey rami communicants. The lateral aspect receives only sympathetic innervation The zygapophyseal joints are innervated by the medial branches of the dorsal rami

Biomechanics Motions at the lumbar spine joints can occur in three cardinal planes: Sagittal (flexion and extension) Coronal (side bending) Transverse (rotation) Six degrees of freedom are available at the lumbar spine

Biomechanics The amount of segmental motion at each vertebral level varies Most of the flexion and extension of the lumbar spine occurs in the lower segmental levels, whereas most of the side bending of the lumbar spine occurs in the mid-lumbar area Rotation, which occurs with side bending as a coupled motion, is minimal, and occurs most at the lumbosacral junction

Biomechanics Flexion At the vertebral level, flexion produces a combination of an anterior roll and an anterior glide of the vertebral body, and a straightening, or minimal reversal of, the lordosis At L 4-5, reversal may occur, but at the L 5-S 1 level, the joint will straighten, but not reverse, unless there is pathology present

Biomechanics Extension Pure extension involves a posterior roll and glide of the vertebra, and a posterior and inferior motion of the zygapophyseal joints, but not necessarily a change in the degree of lordosis

Biomechanics Axial Rotation Axial rotation of the lumbar spine amounts to approximately 13° to both sides The greatest amount of segmental rotation, about 5° occurs at the L 5 and S 1 segment

Examination The physical examination of the lumbar spine must include a thorough assessment of the neuromuscular, vascular and orthopedic systems of the hip, lower extremities, low back and pelvic regions

Examination History The clinician should establish the chief complaint of the patient, in addition to the location, behavior, irritability, and severity of the symptoms Although dysfunctions of the lumbar spine are very difficult to diagnose, the history can provide some very important clues

Examination Systems Review It must always be remembered that pain can be referred to the lumbar spine area from pathological conditions in other regions

Examination Observation Observation involves an analysis of the entire patient as to how they move, and respond in addition to the positions they adopt Although spinal alignment provides some valuable information, a positive correlation has not been made between abnormal alignment and pain

Examination Palpation Whenever it is performed, palpation of the lumbar spine area should be performed in a systematic manner, and should be performed in conjunction with palpation of the hip and pelvic area

Examination Active range of motion Normal active motion, which demonstrates considerable variability between individuals, involves fully functional contractile and inert tissues, and optimal neurological function It is the quality of motion and the symptoms provoked, rather than the quantity of motion that is more important

Examination Combined motion testing Using a biomechanical model A restriction of cervical extension, side bending and rotation to the same side as the pain is termed a closing restriction. This restriction is the most common pattern producing distal symptoms. However, a limitation in cervical flexion accompanied by the production of distal symptoms can also occur A restriction of cervical flexion, side bending and rotation to the opposite side of the pain is termed an opening restriction

Examination Key muscle tests The key muscle tests examine the integrity of the neuromuscular junction and the contractile and inert components of the various muscles With the isometric tests, the contraction should be held for at least five seconds to demonstrate any weakness If the clinician suspects weakness, the test is repeated 2-3 times to assess for fatiguability, which could indicate spinal nerve root compression.

Examination Sensory testing The clinician checks the dermatome patterns of the nerve roots, as well as the peripheral sensory distribution of the peripheral nerves Dermatomes vary considerably between individuals

Examination Position Testing Position testing in the lumbar spine is an osteopathic technique used to determine the level and type of zygapophyseal joint dysfunction

Examination Passive Physiological Intervertebral Mobility testing (PPIVM) These are most effectively carried out if the combined motion tests locate a hypomobility, or if the position tests are negative, rather than as the entry tests for the lumbar spine Judgments of stiffness made by experienced physical therapists examining patients in their own clinics have been found to have poor reliability.

Examination Passive Accessory Intervertebral Movement test (PAIVM) Passive accessory intervertebral movement tests investigate the degree of linear or accessory glide that a joint possesses, and are used on segmental levels where there is a possible hypomobility, to help determine if the motion restriction is articular, peri-articular or myofascial in origin

Intervention Strategies The optimal intervention for patients with acute back pain remains largely enigmatic A number of clinical studies have failed to find consistent evidence for improved intervention outcomes with many intervention approaches

Intervention Strategies Acute phase Goals Decrease pain, inflammation, and muscle spasm Promote healing of tissues Increase pain-free range of segmental motion Regain soft tissue extensibility Regain neuromuscular control Allow progression to the functional stage

Intervention Strategies Functional phase Goals: Correction of imbalances of strength and flexibility Incorporate neuromuscular re-education Strengthening of entire kinetic chain Postural correction and retraining To initiate and execute functional activities without pain and while dynamically stabilizing the spine in an automatic manner