examination of the lumbar spine may be seen as a continuation of the procedure already described for

the cervical and the thoracic spine; the lumbar spine cannot be evaluated in isolation. Abnormalities of the lumbar spine may lead to compensatory or secondary abnormalities in other portions of the spine or pelvis. Symptoms that appear to emanate from the lumbar region may actually be due to abnormalities of adjacent structures. The principles already enumerated for evaluation of the cervical and thoracic spine continue to be of value in the assessment of lumbar disorders.

Because disorders of the lumbar spine often produce pain in the pelvis, the hip, or the thigh, a thorough evaluation of the lumbar spine usually includes examination of these regions. The details of this portion of the examination are outlined in Chapter 5, Pelvis, Hip, and Thigh, and are only alluded to here.

 

• INSPECTION

 

Surface Anatomy and Alignment

POSTERIOR ASPECT

As with the rest of the spine, the dorsal location of the lumbar spine within the body makes the posterior viewpoint the most fruitful one for inspection (Fig. 9-1). When viewed from the posterior aspect, a longitudinal furrow is seen in most patients running down the midline from the thoracic spine to the sacrum. The spinous processes of the lumbar vertebrae run down the center of this furrow, and they are visible as a series of evenly placed bumps in thin individuals. Forward flexion at the waist usually makes the tips of the spinous processes more distinct and visible (Fig. 9-1C).

Paraspinous Muscles. On each side of the spinous processes runs a convex column of muscle. This contour is formed by the bulk of the paraspinous muscle mass. The more superficial column of paraspinous muscles is

 

collectively known as the erector spinae, or sacrospinaiis. The erector spinae is split longitudinally into three components. From medial to lateral on each side, they are the multifidus, the longissimus, and the ilia-costalis muscles. The individual contours of these muscles cannot be discerned because they lie deep to the lum-bodorsal fascia, and they are visualized as a group. The prominence due to the paraspinous muscles should be equal on both sides of the spine. In the presence of paraspinous muscle spasm, the contour of the muscles on one side of the spine may stand out in visibly greater prominence than those on the opposite side. Although almost any painful lesion of the lumbar spine may cause paraspinous spasm, the most common cause of asymmetric spasm is paraspinous muscle strain.

 

Symmetry. As in the rest of the spine, the verification of symmetry is an important part of inspection of the lumbar spine. It should appear that a plumb line suspended from the vertebra prominens at the base of the neck would bisect the lumbar spine and continue on through the center of the natal cleft between the buttocks. In addition to looking for straightness of the lumbar spine itself, the examiner should carefully inspect and compare the space created between the upper limbs and the trunk as the hands hang loosely at the patient's sides. Noting asymmetry of these spaces may allow the examiner to detect a subtle coronal deformity of the spine that would otherwise go undetected.

 

Pelvic Obliquity. The examiner should also verify that the patient's pelvis is level. An imaginary line drawn between the posterior superior iliac spines or the iliac crests should be parallel to the floor. If these landmarks are not clearly visible, the examiner may have to palpate the iliac crests to verify that they are equidistant from the floor. If a pelvic obliquity is found, it may be the result of a deformity within the spine, such as scoliosis or an anomalous vertebra, or it may be secondary to a leg length discrepancy. The possible causes of a leg length

 

335

 

 

 

Figure 9-1 . A, B, and C, Posterior aspect of the lumbar spine. A, spinous processes; B, erector spinae; C, iliac crests; D, posterior facet joints; E, transverse processes. D, Posterior aspect of the lumbar spine in flexion.

discrepancy are discussed in Chapter 5. Pelvis, Hip, and Thigh. In the case of a leg length discrepancy, a secondary compensatory deformity of the spine is usually present. List. Any departure from symmetry in the lumbar spine is usually caused by a coronal plane deformity. A list is an abrupt planar shift of the spine, above a certain point, to one side (Fig. 9-2). This phenomenon typically occurs primarily in the lumbar spine. It is usually a reversible deformity related to pain and associated muscle spasm. A list may be caused by a herniated lumbar disk. In this case, the spine shifts away from the side of the nerve root that is being pinched by the herniated lumbar disk in an attempt to relieve pressure from the affected nerve root. Sometimes, local muscle strain can also result in a list.

Scoliosis. Scoliosis is another major cause of coronal asymmetry (Fig. 9-3A). Although scoliosis is usually considered a coronal deformity of the spine, it is really a helical abnormality involving abnormal vertebral rotation along the axis of the spine. Lumbar scoliosis may be primary or secondary. In primary scoliosis, an actual structural abnormality of the spine is present. In secondary

scoliosis, the curvature represents a compensatory adaptation of an otherwise normal spine to an extrinsic factor, such as muscle spasm or pelvic obliquity related to a leg length discrepancy. If the condition is secondary to a pelvic obliquity, leveling the patient's pelvis by placing blocks or books beneath the shorter limb should cause the deformity to disappear. If a pelvic obliquity has been present for a long time, however, permanent soft tissue contractures may develop; consequently, the deformity ceases to be reversible by leveling the pelvis.

As in the cervical and the thoracic spine, lumbar scoliosis may be idiopathic or due to neurologic disorders or vertebral anomalies. The bulkier lumbar musculature may disguise the spinal curve, and the rib hump that often alerts the examiner to the presence of thoracic scoliosis may be mild or absent. Clues such as pelvic obliquity or asymmetry of the spaces between the upper limbs and the trunk are, therefore, extremely important in detecting lumbar scoliosis.

Skin and Subcutaneous Tissue Abnormalities. The

examiner should also note any abnormalities of the skin

 

 

 

Figure 9-2. A and B, A list to the left. Note the asymmetry of the spaces between the arms and the trunk in A and the increase in the list with flexion in B.

 

 

Figure 9-3. A, Thoracolumbar scoliosis. B, Spondylolisthesis (arrow indicates step-off). (B, From Roth man RH, Simeone FA. The Spine, 3rd ed. Philadelphia. WB Saunders. 1992, p 925.)

 

or subcutaneous tissue of the lumbar region that may indicate underlying spinal abnormalities. A lumbal lipoma, an abnormal hair patch, or a port wine stain may be associated with spina bifida or even myelomeningo-cele. Large tan patches known as cafe au lait spots and nodular skin swellings may indicate neurofibromatosis, a condition that may cause secondary deformity of the spine.

Step-Off Deformity. Severe degrees of spondylolisthesis may produce a visible step-off deformity of the lumbar spine. Normally, the tips of the lumbar spinous processes should protrude posteriorly about the same amount, producing a smooth hollow in the lumbar spine. When spondylolysis occurs, the spinous process and associated posterior elements of the involved vertebra are detached from the rest of the vertebra. In this setting, the body of the involved vertebra and the rest of the spine above it may slide forward, producing a spondylolisthesis. Spondylolisthesis is most likely to occur between L5 and

SI. When the amount of spondylolisthesis is severe, an abrupt displacement or step-off is visible (see Fig. 9-3B). Less severe step-offs may only be palpable.

 

LATERAL ASPECT

Viewing the patient from the lateral aspect allows the examiner to judge the sagittal alignment of the spine. The lumbar spine is normally lordotic, that is, concave posteriorly. A normal lumbar lordosis should exactly complement the thoracic kyphosis and cervical lordosis, so that the base of the occiput rests directly above the sacrum (Fig. 9-4A).

The normal lumbar lordosis, which averages about 60% is important in order to maintain healthy low back biomechanics. Several possible departures from normal lordosis may be seen, including hyperlordosis, decreased lordosis, lumbar flatback deformity, and gibbus deformity.

Hyperlordosis. Hyperlordosis is usually a flexible pos-tural deformity (see Fig. 9-4B). This deformity, also

 

 

 

Figure 9-4. Lateral aspect of the lumbar spine. A, Normal alignment B, Hyperlordosis. C, Flat back deformity. (G From Rothman RH, Simeone FA. The Spine, 3rd ed. Philadelphia, WB Saunders, 1992, p 905.)

 

known as swayback, results in increased prominence of the buttocks. It is usually associated with flexion contrac-ture of the hips, as described in Chapter 5, Pelvis, Hip, and Thigh.

Decreased Lumbar Lordosis. Decreased lumbar lordosis is often a temporary, reversible deformity related to pain and associated muscle spasm. Conditions in which pain is exacerbated by extension of the lumbar spine, such as spondylolysis, may be associated with a reflexive decrease in lumbar lordosis. Ankylosing spondylitis may produce a more rigid decrease in lumbar lordosis.

Lumbar flat back syndrome describes a rigid lumbar spine in which the normal lordosis has been completely lost (see Fig. 9—4C). Compression fractures that result in anterior wedging of the lumbar vertebral bodies can produce lumbar flatback syndrome. Advanced degeneration of the lumbar intervertebral disks may also result in this same deformity. Lumbar flatback syndrome may also occur following a long thoracolumbar spinal fusion for correction of scoliosis. Older surgical instrumentation systems tended to allow for only coronal plane deformity correction and straightened the spine in the sagittal plane, leading to a flatback deformity.

 

Gibbus. A gibbus is a sharp, angular kyphotic deformity often noticed by the protruding spinous process at the apex of the deformity. Gibbus is classically associated with tuberculosis of the spine. In this case, the infection destroys the anterior aspect of a vertebral body and the

adjacent disk space, resulting in a localized collapse of the anterior portion of the vertebral column. Vertebral body collapse due to tumors, other infections, or fractures may also produce a gibbus.

 

Gait

Although gait evaluation is not always considered an integral part of a lumbar spine examination, pain or deformity associated with certain conditions of the lumbar spine may produce characteristic gait abnormalities. A classic example is the gait abnormality that may be associated with sciatica. Sciatica is most commonly caused by a herniated disk at the L5-S1 or the L4-L5 interspace compressing a nerve root that feeds into the sciatic nerve. Because knee extension and hip flexion place further tension on the painful sciatic nerve, the patient with sciatica may attempt to walk with the hip more extended and the knee more flexed than normal. In addition, the patient may display an antalgic gait, putting as little weight as possible on the affected side and then quickly transferring the weight to the unaffected side.

The ability to toe walk and heel walk may also be used to screen for lumbar radiculopathy. These tests allow the examiner to quickly screen for radiculopathy related to the most common lumbar disk herniations. This method also allows the involved muscles to be tested with considerably higher loads than are exerted during manual testing of the same muscle groups.

Heel Walking. Heel walking tests the strength of the ankle dorsiflexors. The patient is asked to walk on his or her heels with the toes held high off the floor (Fig. 9-5). Because this is an unusual activity, the examiner may have to demonstrate the maneuver for the patient. The patient should be asked to take about 10 steps with each foot. This maneuver tests for weakness of the L4 innervated tibialis anterior, which would most commonly be weakened by a herniation of the L3-L4 disk. In the presence of severe weakness, the patient is unable to lift the front part of the foot off the floor at all. In milder degrees of weakness, the patient is not able to lift the forefoot as high off the floor as on the other side, or the muscles are noted to fatigue after a few steps have been taken.

Toe Walking. Toe walking requires the SI innervated gastrocsoleus muscle group that would most commonly be weakened by a herniation of the L5-S1 disk. The patient is asked to walk on the toes with the heels held high off the floor, again taking about 10 steps on each foot (Fig. 9-6). Again, severe weakness is manifested by the patient's complete inability to clear the heel of the involved side off the floor. When more subtle degrees of weakness are present, the heel of the involved side is not held as far off the floor as the heel of the opposite side or the muscles are noted to fatigue after a few steps.

 

 

 

 

Figure 9-6. Toe walking.

 

 

 

 

Figure 9-5. Heel walking. Figure 9-7. Lumbar flexion.

Range of Motion

Motion of the lumbar spine is the result of a complex interaction among bony structures, articulations, and soft tissues. Abnormalities of any of these structures may limit the range of motion of the lumbar spine. The loss of motion may be due to pain, muscle spasm, mechanical block, or neurologic deficit. Range of motion of the lumbar spine is traditionally evaluated with the examiner standing or seated behind the patient. However, the examiner may also need to look from the side to more easily quantify the amount of flexion and extension present.

 

FLEXION

To assess the flexion of the lumbar spine, the patient is asked to bend straight forward at the waist as far as possible (Fig. 9-7). Depending on the amount of flexibility present, the patient may be instructed to attempt to touch the fingertips or the palms to the floor. The amount of flexion present is estimated as the angle between the final position of the trunk and a vertical plane. Thus, 90° of flexion is present when the patient's trunk is parallel to the floor. When measured in this fashion, flexion averages about 80° to 90°.

 

 

 

1. 1. • When the Patient Complains of Low-back and Leg Pain

       

      Major Diagnostic Possibilities Include:

       

      • Herniated disk

      • Spinal stenosis

      • Spondylolisthesis

      • Infection

      • Tumor

        Patient Demographics:

         

      • If the patient is less than 20 years old

        • Infection, tumor or spondylolisthesis more likely

      • If the patient is 20 to 50 years old

        • Herniated disk, spondylolisthesis more likely

      • If the patient is older than 50

        -Spinal stenosis, spondylolisthesis, herniated disk more likely

        Obtain Relevant Medical History:

      • If the patient is immunocompromised or has a history of intravenous drug abuse

        -Infection is a strong possibility

      • If the patient has a history of cancer

        • Metastatic spread to the lumbar spine must be suspected

      • If the patient has a history of repetitive hyperextension of lumbar spine (e.g., gymnast or football lineman)

        -Spondylolisthesis is possible

         

        Ask the Patient about the Onset of Symptoms:

      • Sudden onset

        -Mor e suggestive of herniated disk, infection, or tumor

      • Gradual, insidious onset

        • Spinal stenosis likely

           

          Ask the Patient to Describe Associated Symptoms:

      • Constitutional symptoms such as weight loss, fever, or night sweats

        • Suggestive of tumor or infection

      • Unilateral leg paresthesias, weakness, or pain

        -Typical of herniated disk

      • Bilateral buttock/leg pain and cramping with ambulation

        -Suggestive of spinal stenosis

      • Bowel or bladder symptoms

        • Cauda equina syndrome from a midline disc herniation a possibility and must be ruled out as it is a surgical emergency

      • Pain worse with ambulation but relieved with sitting, bicycling, or activities where lumbar spine is flexed

        • Suggestive of spinal stenosis Relevant Physical Examination:

          GENERAL:

      • Inspection

      • Examination of gait

      • Range of motion

        HERNIATED DISC:

      • Nerve root tension tests (straight-leg raising, Lasegue's test, contralateral straight-leg raising, slump test, bowstring sign)

      • Flexion of lumbar spine to reproduce leg symptoms

      • Palpation of sciatic notch for tenderness

      • Neurologic testing for deficit in the distribution of the involved nerve root

        SPINAL STENOSIS:

      • Decreased lumbar range of motion

      • Leg symptoms reproduced with lumbar spine extension

      • Neurologic testing for deficit in the distribution of the involved nerve root

        SPONDYLOLISTHESIS:

      • Inspection for decreased lumbar lordosis

      • Hyperextension of lumbar spine may reproduce back pain; relieved wit h flexion

      • Palpation for step-off

      • Straight-leg raising test to elicit hamstring tightness

      • Neurologic testing

        INFECTION/TUMOR:

      • Palpation for point tenderness at involved level

      • Palpation for associated muscle spasm

      • Neurologic testing

      Another way of quantifying lumbar flexion is to measure the distance from the patient's fingertips to the floor. In the average patient, the fingertips come to rest about 10 cm from the floor. The range of variation in lumbar flexion, however, is quite large. Flexion tends to decrease with age. Because lumbar flexion increases pressure on the intervertebral disks and places tension on sciatic nerve roots, herniation of L4-L5 and L5-S1 disks is frequently associated with painful, limited flexion of the lumbar spine. While assessing lumbar flexion, the examiner should also note whether the spine remains straight during flexion. The deformities associated with scoliosis and a lumbar list may both be accentuated by flexion of the spine (see Fig. 9-2).

      It must be recognized that much, if not most, of the motion observed during forward bending is due to flexion at the hips, rather than true flexion of the lumbar spine. It is difficult to eliminate hip flexion and measure pure spine flexion. However, two methods are available to ensure that at least some of the flexion is taking place in the spine. The first is to observe the behavior of the normal lumbar lordosis as the patient bends forward. If flexion is actually taking place within the lumbar spine, the normal lordotic contour should flatten out and even mildly reverse itself into a slight kyphosis. If the contour of the lordosis remains unchanged during forward bending, the examiner may conclude that little flexion of the lumbar spine is actually occurring. The second technique for verifying that flexion is occurring within the spine is the tape measurement of the apparent increase in the length of the spine during flexion. This is done with the modified Schober test as described in Chapter 8, Cervical and Thoracic Spine. This method is really just a way of quantifying the change in spinal contour noted by observing the reversal of the lumbar lordosis.

      EXTENSION

      To test for extension of the lumbar spine, the examiner asks the patient to lean backward as far as possible (Fig. 9-8). The amount of extension is quantified by estimating the angle between the trunk and a vertical line. In a normal patient, about 20° to 30° of extension is possible. As with the assessment of flexion, the examiner should not only observe the amount of motion possible but also determine whether the maneuver causes the patient pain. A number of different conditions may limit lumbar spine extension or cause it to be painful. Because extension tends to narrow the diameter of the spinal canal, patients with abnormal narrowing of the spinal canal tend to avoid further extension. The most common example of this is degenerative spinal stenosis, but post-traumatic deformities and space-occupying lesions, such as tumors, may produce the same picture. Lumbar spine extension may also be limited or painful in the presence of disorders of the posterior elements of the vertebrae. Examples include spondylolysis, tumors of the posterior elements, and degenerative arthritis of the posterior facet joints.

       

       

       

      Figure 9-8. Lumbar extension.

       

      LATERAL BENDING

      Lateral bending is tested by asking the standing patient to lean as far as possible to each side. The examiner should stabilize the patient's pelvis with a hand on each iliac crest (Fig. 9-9). This motion actually involves a combination of lateral bending and rotation of the vertebral column. The amount of lateral bending present is difficult to quantitate. It may be estimated by drawing an imaginary line between the vertebra prominens and the sacrum and estimating the angle between this line and the vertical. The average amount of lateral bending present in a normal patient is 20° to 30°.

      The examiner should look for asymmetry between the two sides. Patients with herniated disks may avoid lateral bending toward the side of the herniation, as this causes the nerve root to further impinge on the herniated disk. The lateral bending test also provides an opportunity to verify an impression of paraspinous muscle spasm. To do this, the examiner should palpate the paraspinous muscles during the lateral bending maneuver (Fig. 9-10). Normally, the muscles on the side to which the patient is bending should relax and soften. If they remain tight and rigid, this is evidence that they are in spasm.

       

       

       

      Figure 9-9. Lateral bending. A, Right. B, Left. Examiner has been omitted lor clarity. Examiner should normally sit behind the patient with a hand on each iliac crest to stabilize the pelvis.

       

       

       

      ROTATION

      Lumbar spine rotation is estimated by asking the patient to rotate or twist in each direction as far as possible. The examiner should prevent rotation of the pelvis with a stabilizing hand on each iliac crest (Fig. 9-11). The amount of rotation is difficult to quantitate, but it may be judged by estimating the angle between the new plane of the rotated shoulders and the coronal plane of the stabilized pelvis. The normal range is about 30° to 40° in each direction.

       

      • PALPATION

       

       

      Figure 9-10. Palpation of the paraspinoos muscles during lateral bending.

      POSTERIOR ASPECT

      As with the cervical spine, the positioning of the patient during palpation depends on the clinical situation. During an elective office examination, palpation normally is carried out with the patient standing or prone. If the patient is encountered in an emergency situation, however, palpation is carried out in whatever position the patient was originally found. Because the anterior aspect of the lumbar spine is located deep to the abdominal cavity, palpation is normally confined to the posterior aspect.

      Spinous Processes. Firm palpation in the posterior midline allows the examiner to identify the tips of the spinous processes of the lumbar vertebrae (see Fig. 9-1). Linking the spinous processes are the supraspinous and

       

       

       

      Figure 9-11. Lumbar spine rotation.

       

      intcrspinous ligaments. If the patient is standing, palpation is most comfortably accomplished with the examiner in the seated position. For orientation, the examiner should identify the top of each iliac crest and draw an imaginary line between the two. This line usually passes through the interspace between the L4 and the L5 spinous processes (Fig. 9-12). The examiner can then identify the individual spinous processes by counting upward or downward from the L4-L5 interspace. Localized tenderness at a particular level may indicate pathology at that level. Conditions that may cause tenderness localized to one level include sprains or disruptions of the posterior ligaments of the spine, fractures of the posterior elements, and tumors of the posterior elements. In the presence of degenerative arthritis, or spondylosis, tenderness over the posterior vertebrae is of uncertain significance. Marked superficial lumbar tenderness, especially in response to very light palpation, suggests the possibility of symptom magnification.

      In the presence of spondylolisthesis, palpation of the spinous processes may help confirm the examiner's visual impression of a step-off above the involved vertebra. The amount of slippage usually must be at least 50% of the diameter of the lumbar vertebral bodies before the step-off can be detected by physical examination.

      Paraspinous Muscles. On each side of the spinous processes lie the muscular columns of the erector spinae, or sacrospinalis, composed of the multifidus,

       

      Figure 9-12. Palpation of the iliac crests.

       

      the longissimus, and the iliocostalis muscles. The individual components cannot normally be distinguished by palpation. In the presence of muscle spasm, the paraspinous muscle column may appear more prominent and feel firmer than usual. Muscle spasm may reflect a local muscle injury or may be a response to a nearby locus of pain within the spine itself. If muscle spasm is suspected, the patient should be asked to bend toward the involved side while the examiner continues to palpate the paraspinous muscle in question (see Fig. 9-10). Normally, the paraspinous muscles on the side to which the patient is bending should soften and relax. If they remain firm, the impression of spasm is confirmed. Unilateral muscle spasm may cause a list or reactive scoliosis; bilateral muscle spasm may result in the loss of the normal lumbar lordosis.

      The examiner should also note whether the paraspinous muscles are tender. Diffuse muscular tenderness may reflect a strain of the muscles being examined. Trigger points, tender nodules within the paraspinous muscles, should also be noted. Trigger points are frequently a reaction to a painful stimulus to the paraspinous muscles. They may also indicate the presence of fibromyalgia.

      Other Bony Structures. The posterior facet joints of the lumbar spine are located deep to the paraspinous muscles just lateral to the spinous processes. Localized tenderness over these joints may be caused by facet joint arthritis or a painful facet joint syndrome. Further

      laterally, the transverse processes are also located deep to the paraspinous muscles and are not distinctly palpable. However, the finding of localized unilateral tenderness deep to the paraspinous muscles following trauma should suggest the possibility of a transverse process fracture.

      Pain originating in the lumbar spine must frequently be distinguished from pain originating in the sacroiliac joint, the posterior pelvis, the hip, or the thigh. Examination of the lumbar spine should, therefore, include palpation of the sacrum and the coccyx, the sacroiliac joint, the sciatic notch, and the other bony and soft tissue structures of the posterior pelvis, the hip, and the thigh. The palpation of these structures is described in Chapter 5, Pelvis, Hip, and Thigh.

       

      • MANIPULATION

        Muscle Testing

        Strength testing of the muscles that move the lumbar spine is not usually emphasized. Nevertheless, the abdominal and the lumbar musculature fulfills an important role by

        reducing the load on the static elements of the spine. A general assessment of the function of these muscle groups is, therefore, helpful in evaluating the common strain and overuse disorders that are frequent causes of low back pain. Flexion of the lumbar spine is powered by the abdom-

        inal muscles, particularly the rectus abdominis. The function of these muscles may be assessed by having the patient perform a crunch, or modified sit-up. In this exercise, the patient lies supine on the examination table with the hip and the knees flexed, hands behind the head. The patient is then instructed to raise his or her shoulders off the table (Fig. 9-13). The height to which the shoulders can be raised and the number of repetitions possible vary tremendously among individuals according to flexibility, fitness level, and prior training. A patient who cannot raise the shoulders even once has significantly weak abdominal muscles.

        Extension of the lumbar spine is powered by the erector spinae muscle groups. To assess the function of these muscles, the patient is placed in the prone position on the examination table with the hands behind the head. The patient is then asked to lift the chest off the table {Fig. 9-14). Again, the height that the shoulders rise off the

         

         

         

   2. • When the Patient Complains of Low-Back Pain after Trauma

       

      Major Diagnostic Possibilities Include:

      • • Fracture

        • Ligamentous injury

        • Low-back strain/sprain

        • Herniated disk

          May be necessary to rule out underlying pathologic lesion of the vertebra such as tumor or osteoporosis.

          Ask the Patient to Describe the Original Injury Episode:

        • Major trauma such as a motor vehicle accident or a fall fro m a height with immediate pain

          • Exclude fracture or ligamentous injury

        • Minor trauma such as a lifting or twisting injury

          -Consider low-back strain/sprain, vertebral compression fracture in osteoporotic patients or herniated intervertebral disk

          Ask the Patient to Describe their Current Symptoms:

        • Constant low-back pain, made worse with any activity

          • Exclude fracture or major ligamentous injury

        • Low-back pain, made worse with bending or twisting

          • Suggestive of a low-back strain/sprain

            -Herniated disk, fracture, or ligamentous injury remain possibilities

        • Low-back pain associated with radiating leg pain,

          paresthesias or weakness

          -Indicates likely neural compression arising from herniated disk, fracture, or ligamentous injury wit h neural encroachment or injury

        • Low-back pain associated wit h bowel or bladder symptoms

          • Suggestive of a large herniated disk wit h associated cauda equina syndrome (a surgical emergency)

          • May be caused by fracture or ligamentous injury resulting in neural compression or cauda equina injury

            Relevant Physical Examination:

            GENERAL:

        • If suspicious of spinal fracture or dislocation, immobilize patient and assess for hemodynamic stability and other associated injuries

        • Inspection

        • Examination of gait

        • Range of motion

          FRACTURE OR LIGAMENTOUS INJURY:

        • Inspection for swelling and ecchymosis at the level of injury

        • Palpation for tenderness at the level of injury

        • Palpation for step-off

        • Neurologic testing for associated upper or lower motor neuron deficits

          LOW-BACK STRAIN:

        • Palpation for paraspinal muscle tenderness or spasm

        • Inspection of gait for list (variable)

        • Range of motion typically painful

        • Neurologic examination typically normal

          HERNIATED DISK:

        • Flexion of lumbar spine to reproduce leg symptoms

        • Palpation of sciatic notch for tenderness

        • Nerve root tension signs (straight-leg raising, Lasegue's test, contralateral straight-leg raising, slump test, bowstring sign)

        • Neurologic testing for deficit in the distribution of the involved lumbar nerve root

           

           

           

   3. • When the Patient Complains of Low-Back Pain without Preceding Trauma

 

Major Diagnostic Possibilities Include:

• • Low-back strain

  • Degenerative disc disease

  • Lumbar arthritis

  • Herniated disk

  • Spondylolysis/spondylolisthesis

  • Spinal deformity

  • Compression fracture

  • infection

  • Tumor

  • Nonorganic low-back pain Patient Age:

    IN PATIENTS LESS THAN 20 YEARS OLD:

  • Spondylolysis; isthmic spondylolisthesis

  • Tumor

    IN PATIENTS 20 TO 50 YEARS:

  • Low-back strain

  • Degenerative disk disease

  • Herniated disk

  • Spondylolisthesis

  • Nonorganic low-back pain

    IN PATIENTS OLDER THAN 50 YEARS:

  • Low-back strain

  • Lumbar arthritis

  • Compression fracture

  • Infection

  • Tumor

  • Nonorganic low-back pain General Medical History:

  • If the patient is immunocompromised or has a his-

    tory of intravenous drug abuse

    • Infection is a strong possibility

  • If the patient has a history of cancer

    • Metastatic spread to the lumbar spine must be suspected

  • If the patient has a history of osteoporosis

    -Compression fracture should be considered Ask the Patient to Describe Associated Symptoms:

  • Constitutional symptoms such as weight loss, fever,

    or night sweats

    -Suggestive of tumor or infection

  • Unilateral leg paresthesias, weakness and pain

    -Typical of herniated disk

    • May be suggestive of lumbar arthritis with spinal stenosis

  • Bilateral buttock/leg pain and cramping wit h ambulation

    -Suggestive of lumbar arthritis with spinal stenosis

    • Other possibilities include tumor or trauma resulting in neural compression

• Bowel or bladder symptoms

  - May be the result of neural compression caused by a larger disc herniation, tumor or fracture

  Relevant Physical Examination:

  GENERAL:

  Inspection Palpation

  Examination of gait Range of motion Neurologic testing

  COMPRESSION FRACTURE:

  Palpation for tenderness at the level of injury Inspection for swelling and ecchymosis at the level of injury

  Palpation for step-off

  Pain wit h range of motion

  SPONDYLOLYSIS/SPONDYLOUSTHESIS:

  Inspection for decreased lumbar lordosis Hyperextension of lumbar spine to determine if pain reproduced

  Palpation for step-off

  Straight-leg raising test to elicit hamstring tightness Neurologic testing

  LUMBAR SPONDYLOSIS:

  Decreased lumbar range of motion Pain with lumbar range of motion

  INFECTION/TUMOR:

  Palpation for point tenderness at involved level Palpation for associated muscle spasm Neurologic testing

  SPINAL STENOSIS:

  Inspection for loss of lumbar lordosis Sciatic notch tenderness

  Passive spine extension reproduces neurogenic claudication

  Vascular examination to exclude vascular claudication

  HERNIATED DISK:

  Nerve root tension tests (straight-leg raising, Lasegue's test, contralateral straight-leg raising, slump test, bowstring sign)

  Flexion of lumbar spine to reproduce leg symptoms Palpation of sciatic notch for tenderness Neurologic testing for deficit in the distribution of the involved root

  LOW-BACK STRAIN:

  Palpation for paraspinal muscle tenderness or spasm

  Inspection of gait for list (variable) Neurologic examination should be normal

  NONORGANIC LOW-BACK PAIN

• Waddell's signs

 

 

 

Figure 9-13. Modified situp demonstrates abdominal muscle strength.

Figure 9-14. Active extension demonstrates erector spinae strength.

 

table and the number of repetitions possible vary widely among patients according to flexibility, fitness level, and training. The pain associated with disorders of the posterior elements of the lumbar spine, such as spondylolysis or facet joint arthritis, or of spinal stenosis may be exacerbated by this test.

 

Neurologic Examination

SENSORY EXAMINATION

The approximate areas of sensory innervation from the lumbar and the sacral nerve roots are shown in Figure 9-15. As with the cervical and the thoracic nerve roots, there is considerable overlap in the sensory dermatomes, and the exact distribution of each dermatome varies somewhat from one individual to another. The initial screening for sensory deficits is usually done with light touch and sharp-dull discrimination testing, as described in Chapter 8, Cervical and Thoracic Spine. The sensory, motor, and reflex tests for each dermatome are summarized in Table 9-1 .

The LI, L2, and L3 dermatomes run in broad bands obliquely across the anterior thigh. LI sensation is tested in the anterior proximal thigh near the inguinal ligament

(Fig. 9-16A). Sensation supplied by the L2 nerve root is tested over the anteromedial thigh, midway between the inguinal ligament and the patella (Fig. 9-16B). L3 sensation may be evaluated by testing the skin just proximal or medial to the patella (Fig. 9-16C). The L4 nerve root supplies sensation to the medial leg and the ankle. It is best tested by examining the sensation in the area just proximal to the medial malleolus (Fig. 9-16D). The L5 dermatome includes the lateral and the anterolateral leg and the dorsum of the foot. L5 sensation is usually tested by examining the area just proximal to the first web space (Fig.9-16£).

The sensory distribution of the S1 nerve root includes the posterior calf, the plantar surface of the foot, and the lateral toes. S1 sensation may be reliably tested over the posterolateral aspect of the heel (see Fig. 9-16F). The S2 nerve root supplies the posterior thigh and the proximal calf. S2 sensory function may be tested by evaluating sensation in the center of the popliteal fossa (see Fig. 9-16G). The lower sacral nerve roots (S3, S4, S5) supply the sensation in the perianal area. The dermatomes are arranged in concentric rings around the anus, with the S3 dermatome being the most peripheral and the S5 being the most central.

 

TABLE 9-1 PHYSICAL FINDINGS IN LUMBOSACRAL RADICULOPATHIES

 

DERMATOME SENSORY TESTING MOTOR TESTING REFLEX TESTING

 

 

L l Anterior proximal thigh near inguinal ligament

Iliopsoas (seated hip flexion)

L 2 Mid anteromedial thigh Iliopsoas (seated hip flexion)

L 3 lust proximal or medial to patella Quadriceps Patellar tendon reflex (secondary)

L4 Medial lower leg and ankle Tibialis anterior Patellar tendon reflex

L 5 Lateral and anterolateral Extensor hallucis longus Tibialis posterior reflex

leg and dorsal foot Extensor digitorum brevis Gluteus medius

Medial hamstring reflex

SI Posterior calf, plantar foot, Gastrocsoleus Achilles' reflex and lateral toes Peronei

Gluteus maximus

S2 Posterior thigh and proximal calf Rectal examination

S3, S4, S5 Perianal area Rectal examination

 

 

C D

Figure 9-15. A-D, Lumbar and sacral dermatomes. (A and C, After Foerster. B and D, After Keegan and Garrett.)

MOTOR EXAMINATION

The spinal cord terminates at about the L1-L2 level, but its lower nerve roots continue distally as the cauda equina. Each pair of nerve roots exits the spine at the neural foramen formed by the vertebra of the same number and the one below. Thus, the L4 nerve root exits at the L4-L5 neuroforamen, the L5 nerve root exits at the L5-S1 ncuroforamen, and so forth. However, when a lumbar disk herniation occurs, the disk tends to compress the next lower nerve root. Thus, the L5-S1 disk, the most common to herniate, usually compresses the S1 nerve root. Similarly, the L4-L5 disk usually compresses the L5 nerve root, and the L3-L4 disk, the least common of the three to herniate, usually compresses the L4 nerve root. Higher nerve roots are unlikely to be compressed by disk herniations. However, these higher nerve roots may be affected by other types of pathology, such as spinal fractures or dislocations; and congenital malformations, such as spina bifida; tumors; and infections.

L1 and L2 Nerve Roots. The L1 and L2 nerve roots supply the iliopsoas muscle, the primary hip flexor. To test

the iliopsoas, the patient is seated with the knees flexed to 90° over the end or the side of the examination table. The patient is instructed to raise the thigh off the examination table while maintaining flexion of the knee. The examiner then presses downward on the patient's knee with both hands, asking the patient to resist as strongly as possible (Fig. 9-17). In a normal patient, the examiner should be able to overcome the iliopsoas with moderate difficulty.

L3 Nerve Root The L3 nerve root is usually assessed by evaluating quadriceps strength, although the quadriceps is also innervated by L2 and L4. The quadriceps is also tested with the patient sitting on the end or the side of the examination table. The patient is asked to extend the knee fully and then to maintain the knee in full extension while the examiner pushes downward on the lower leg just above the ankle {Fig. 9-18). In a normal patient, the examiner should be unable to overcome the quadriceps and initiate knee flexion. In fact, in a strong patient, the examiner may begin to lift the patient's pelvis off the examination table as the lower leg is pushed downward with the patient's knee locked in full extension.

 

 

Figure 9-16. Sensory evaluation by lumbar and sacral dermatome.

A, L1. B, L2.C L3.

 

 

L3

 

 

 

Figure 9-16, cont'd. D, L4. E, L5. F, S1, G, S2.

 

L4 Nerve Root The L4 nerve root is usually evaluated by testing the strength of the tibialis anterior muscle. As previously noted, the examiner may screen for tibialis anterior weakness by asking the patient to heel walk. Specific manual resistive testing of the tibialis anterior is accomplished with the patient seated on the end or the side of the examination table. The patient is asked to maximally dorsiflex the ankle on the side being tested. The patient is then instructed to maintain this position while the examiner presses downward on the foot and attempts to passively plantar flex the ankle (Fig. 9-19). In a normal patient, the examiner should be unable to overcome the strength of the tibialis anterior.

L5 Nerve Root The L5 nerve root provides the motor supply of the long toe extensors. It is most commonly tested by evaluating the strength of the extensor hallucis longus. To test the extensor hallucis longus, the examiner asks the seated patient to pull up or extend the great toe. The examiner then stabilizes the medial aspect of the patient's foot with one hand while pressing downward on the distal phalanx of the great toe with the fingers or the thumb of the other hand. The patient is instructed to resist the examiner's attempt to flex the interphalangeal joint of the toe (Fig. 9-20A).

When normal strength is present, it should be difficult for the examiner to overcome the strength of the

 

 

 

 

 

 

L1-L2

 

Figure 9-17. Assessing LI and L2 motor function (iliopsoas strength),

 

extensor hallucis longus. In some patients, the patient's ability to demonstrate strength of the extensor hallucis longus may be limited by nonneuroiogic factors, such as the presence of severe bunions or the anatomic changes due to prior bunion surgery. In these patients, the examiner may assess the motor supply of the L5 nerve root by testing the other digital extensors or the gluteus medius.

The extensor digitorum longus is assessed in a manner analogous to that used for the extensor hallucis longus. In this case, the examiner stabilizes the forefoot with one hand and asks the patient to extend the toes as far as possible. The examiner then instructs the patient to

 

 

 

 

Figure 9-18. Assessing L3 motor function (quadriceps).

Figure 9-19- Assessing L4 motor function (tibialis anterior strength).

 

maintain the extended position of the toes while the examiner attempts to passively flex the toes with his or her fingers (see Fig. 9-20B). In a normal patient, the examiner is able to overcome the strength of the toe extensors with moderate difficulty.

The gluteus medius is evaluated by assessing the strength of hip abduction. For this test, the patient is in the lateral position on the examination table and is asked to abduct the lower limb away from the table while maintaining knee extension. The examiner then instructs the patient to maintain the position of abduction while the examiner presses downward on the distal thigh, attempting to push the thigh back toward the table (see Fig. 9-20C). In a normal patient, the examiner has considerable difficulty overcoming the strength of the gluteus medius. In stronger patients, the examiner may be unable to do so.

S1 Nerve Root. The SI nerve root provides motor supply to the plantar flexors, the evertors of the ankle, and the extensors of the hip. As previously described, the examiner may screen for weakness of the plantar flexors of the ankle by asking the patient to toe walk. Primary plantar flexion strength is provided by the gastrocsoleus complex, with assistance from the toe flexors. Manual resistance testing of the gastrocsoleus is usually carried out in the seated patient. The examiner stabilizes the patient's ankle with one hand and instructs the patient to passively plantar flex the ankle. The patient is told to maintain this position while the examiner attempts to force the ankle back into dorsiflexion by pressing upward on the patient's forefoot with the examiner's other hand (Fig. 9-21 A). In a normal patient, the examiner is unable to overcome the powerful plantar flexor muscles and initiate dorsiflexion.

The peroneus longus and brevis muscles, the principal evertors of the foot, are tested in the same basic position as the gastrocsoleus complex. The examiner

 

 

Figure 9-20. Assessing L5 motor function. A, Extensor hallucis longus. B, Extensor digitorum longus. C, Gluteus medius.

 

 

stabilizes the patient's leg with one hand and asks the patient to rotate the foot outward. The examiner may have to passively place the patient's foot in eversion to communicate the desired position. The patient is then instructed to maintain the foot in the everted position while the examiner attempts to invert the foot by pressing inward on the lateral aspect of the foot (see Fig. 9-21B). In the normal patient, the examiner is able to overcome the strength of the evertors only with difficulty.

The gluteus maximus is also supplied by the SI nerve root. To test it, the patient is asked to lie prone on the examination table and to flex the knee on the side being tested. The patient is then instructed to raise the thigh off the table. Finally, the examiner presses downward on the thigh with both hands while asking the patient to maintain the position of hip extension (see Fig. 9-21C). In a normal patient, the examiner experiences considerable difficulty pushing the thigh back to the table.

S2, S3, and S4 Nerve Roots. The S2, S3, and S4 nerve roots may be compressed or injured by tumors or fractures of the sacrum, or, more commonly, affected by spinal cord injury at a higher level. In the presence of spinal cord

 

injury, the finding of sacral sparing, the preservation of some function of the sacral nerve roots, is a positive factor in predicting the potential for recovery of function.

The S2, S3, and S4 nerve roots are the principal nerve supply for the bladder, and they also supply the intrinsic muscles of the feet. Motor testing for these functions is difficult. The motor function of the sacral nerve roots is, therefore, usually tested by performing a rectal examination. When normal function is present, the examiner should note fairly firm resistance as the examining finger enters the rectum. The patient is then instructed to try to squeeze the examiner's finger, thus contracting the external anal sphincter. This should produce a strong, readily palpable feeling of constriction around the examiner's finger.

 

REFLEX EXAMINATION

Deep tendon reflexes are not easily assessed for all the lumbar and sacral nerve roots. Two principal deep tendon reflexes are normally tested: the patellar tendon reflex, which primarily involves the L4 nerve root, and the Achilles tendon reflex, which primarily involves the S1 nerve root.

 

S

Figure 9-21. Assessing SI motor function. A, Gastrocsoleus. B, Peroneus longus and brevis. C, Gluteus maximus.

 

 

1

 

Patellar Tendon Reflex (L4). The patellar tendon reflex is usually assessed with the patient seated on the side of the examination table with the knees flexed and the feet dangling. The examiner then sharply strikes the midportion of the patellar tendon with the flat side of a rubber reflex hammer. The examiner's other hand may rest lightly on the patient's quadriceps to feel for a muscle contraction (Fig. 9-22.4).

to most patients, a contraction of the muscle is felt in response to the strike of the hammer, and in some patients the knee is seen to extend slightly. If no reflex is observed, the examiner may try to reinforce the reflex. To do this, the patient is instructed to hook the fingers of both hands together and pull against each other isomet-rically. While the patient is pulling, the examiner again strikes the patellar tendon (Fig. 9-22B). This technique

may produce a patellar tendon reflex in patients in whom the reaction is otherwise unobtainable.

The patellar tendon reflex is more difficult to elicit than the Achilles tendon reflex. In some normal patients, the patellar tendon reflex is symmetrically absent. As in many other aspects of the physical examination, lack of symmetry is the key to evaluating this test. The patellar tendon reflex is primarily used to evaluate the L4 nerve root. Some contribution from L3 is also present.

Tibialis Posterior Reflex (L5). The available reflexes for the L5 nerve root are difficult to elicit. They include the tibialis posterior reflex and the medial hamstring reflex. The tibialis posterior reflex is evaluated in the seated patient. The examiner holds the patient's foot in a small amount of eversion and dorsiflexion and strikes the posterior tibial tendon just below the medial malleolus. The

 

 

 

Figure 9-22. A, Patellar tendon reflex (L4 nerve root). B, Reinforcement technique.

 

examiner may also place a finger on the posterior tibial tendon and strike the finger instead of striking the tendon directly (Fig. 9-23A). When the reflex is elicited, a slight plantar flexion inversion response is noted.

Medial Hamstring Reflex (L5). To elicit the medial hamstring reflex, the patient is placed in the prone position. The examiner passes one hand underneath the

patient's leg and places the thumb of that hand on the semitendinosus tendon in the popliteal fossa. The patient's leg is allowed to rest on the examiner's forearm so that the patient's knee is somewhat flexed. The examiner then strikes the thumb, which is pressing on the semitendinosus tendon, with the pointed end of the hammer (see Fig. 9-23B). When the reflex is elicited, the

 

 

 

 

Figure 9-23. L5 nerve root reflexes. A, Tibialis posterior. B, Medial hamstring.

examiner feels a contraction transmitted through the semitendinosus tendon or actually sees slight flexion of the knee take place.

Achilles' Tendon Reflex (S1). The Achilles tendon reflex represents the S1 nerve root. This reflex may be elicited in the patient who is seated with the legs dangling comfortably off the end or side of the examination table. The examiner gently dorsiflexes the foot to place the Achilles tendon under tension, and then strikes the Achilles about 3 cm above the calcaneus using the flat end of the reflex hammer (Fig. 9-24A).

In most patients, this action produces a visible twitch of the ankle into plantar flexion. As with other deep tendon reflexes, a unilateral decrease in the magnitude of or disappearance of the Achilles reflex suggests a lower motor neuron lesion. The most common cause of this picture is a herniated L5-S1 disk impinging the ipsilateral S1 nerve root. Bilateral hyperreflexia suggests the possibility of an upper motor neuron lesion.

If the examiner experiences difficulty in eliciting the Achilles tendon reflex, the use of reinforcement techniques is often helpful. A convenient method for reinforcing the Achilles tendon reflex is to ask the patient to kneel on the examination table with the feet projecting a few inches past the end or side (see Fig. 9—24B). The examiner then strikes each Achilles in turn as already described. This technique brings out the Achilles tendon reflex in the vast majority of individuals.

PATHOLOGIC REFLEXES

If undue briskness of the Achilles or the patellar tendon reflexes leads the examiner to suspect the presence of an

upper motor neuron lesion, the provocative tests for ankle clonus and the Babinski sign should be carried out. The details of these procedures are described in Chapter 8, Cervical and Thoracic Spine. It is important to remember that the spinal cord usually ends at the inferior margin of the L1 vertebra. Distal to this level, the nerve roots that constitute the cauda equina function very much like peripheral nerves. Thus, for an upper motor neuron picture to occur, a lesion must typically be situated at the L1 level or higher.

 

Nerve Tension Tests

An important component of the lumbar spine examination is to determine whether evidence of nerve root compression exists. Nerve root compression is usually considered probable when stretching the peripheral nerve associated with the nerve root in question reproduces pain in the distribution of that nerve. The most important peripheral nerves deriving from the lumbar and the sacral nerve roots are the femoral and the sciatic nerves. The femoral nerve runs down the anteromedial aspect of the thigh and is formed by the L2, L3, and L4 nerve roots. The sciatic nerve runs down the posterior thigh and is formed by the L4, L5, S1, S2, and S3 nerve roots.

STRAIGHT-LEG RAISING TEST

The straight-leg raising test is the most well-known nerve tension test for the lumbar spine. The test is performed with the patient lying in a comfortable supine position with the head and pelvis flat. While full knee extension is maintained, one of the patient's feet is slowly lifted off the table. The limb is progressively elevated until

 

 

 

 

 

Figure 9-24. A, Achilles' tendon reflex (S1 nerve root). B, Reinforcement technique.

maximal hip flexion is reached or the patient asks the examiner to stop owing to pain (Fig. 9-25). The angle formed by the lower limb and the examination table at the point of maximal elevation is noted, and the procedure is repeated with the opposite limb.

In a normal patient, straight-leg raising of 70° to 90° should be possible and may be accompanied by a feeling of tightness in the posterior thigh. In the presence of sciatica, the angle of hip flexion is reduced and the patient reports shooting pain radiating down the posterior thigh and often into the lower leg along the distribution of the sciatic nerve. Straight-leg raising stretches the L5 and SI nerve roots 2 mm to 6 mm, but it puts little tension on the more proximal nerve roots. An abnormal straight-leg raising test, therefore, suggests a lesion of either the L5 or the S1 nerve root. Beyond 70° of hip flexion, deformation of the sciatic nerve occurs beyond the spine. Sciatic pain that is reproduced only with hip flexion beyond 70°, therefore, suggests the possibility of sciatic nerve compression outside the spinal canal. If the patient with limited straight-leg raising reports tightness in the posterior thigh rather than sciatica, hamstring tightness is the probable cause. Hamstring tightness may be associated with a wide variety of conditions, including spondylolysis. Lasegue's test, discussed later, does not exacerbate the discomfort of hamstring tightness the way it exacerbates sciatica. Recent studies have confirmed that the straight-leg raise test is extremely sensitive (0.9) but rather less specific (0.26) for confirming the presence of a compressed or irritated lumbar nerve root.

 

CROSSED STRAIGHT-LEG RAISING TEST

Performing the straight-leg raising test on the side opposite that of the sciatica is called the crossed straight-leg raising test. For example, if a patient complains of right-sided sciatica, the examiner performs a straight-leg raising test on the patient's left side. If this maneuver reproduces or exacerbates the patient's right-sided sciatica, the result is extremely sensitive and specific for a herniated L5-S1 or L4-L5 lumbar disk. The crossed straight-leg raising test is less sensitive (.29) but more specific (.88) than the straight-leg raising test for confirming a compressed or irritated lumbar nerve root.

LASEGUE'S TEST

Lasegue's test is a progression of the straight-leg raising test. To perform Lasegue's test, the examiner carries out the straight-leg raising test, pausing when the patient complains of reproduction of his or her typical sciatic pain. While maintaining the degree of hip flexion at which sciatic pain is induced, the examiner passively dorsiflexes the foot of the leg being raised (Fig. 9-26). This maneuver further deforms the sciatic nerve. If the patient's radicular pain is exacerbated, the diagnosis of sciatica is strengthened. Lasegue's test may also reproduce radicular pain in some cases of lumbar disk herniation in which the straight-leg raising test is otherwise negative. The results of both the straight-leg raising test and the Lasegue test are abnormal in most cases of lumbar disk herniation, however. The sensitivity of Lasegue's test is reported to be 0.7.

 

 

 

 

 

Figure 9-25. Straight-leg raising test. Figure 9-26. Lasegue's test.

 

BOWSTRING SIGN

MacNab described another confirmatory test for sciatic nerve tension known as the bowstring sign. To elicit the bowstring sign, the examiner again begins by performing the straight-leg raising test to the point of reproduction of the patient's radicular pain. The knee is then flexed 90°, which usually relieves the patient's symptoms. Digital pressure is then applied to the popliteal fossa over the posterior aspect of the sciatic nerve (Fig. 9-27). If this again reproduces the patient's radicular pain, the impression of sciatica is further confirmed. The sensitivity of the bowstring sign is similar to that of Lasegue's test in confirming lumbar radiculopathy (0.69).

SLUMP TEST

The slump test is really a variant of the straight-leg raising and Lasegue's tests performed in the seated position. The slump test is a progressive series of maneuvers designed to place the sciatic nerve roots under increasing tension. The patient begins the slump test sitting on the side of the examination table with the back straight, looking straight ahead (Fig. 9-28A). The patient is then encouraged to slump, allowing the thoracic and lumbar spines to collapse into flexion while still looking straight ahead (Fig. 9-28B). The next step is to fully flex the cervical spine (Fig. 9-28C). The patient is then instructed to extend one knee, thus performing a straight-leg raise (Fig. 9-28D). The patient then dorsiflexes the foot on the same side, thus duplicating the Lasegue test (Fig. 9-28E). The process is then repeated with the opposite lower extremity.

At each stage in the procedure, the patient informs the examiner what is being felt and whether radicular pain is produced. Many normal individuals feel tightness

in the lower back and the thigh with this series of maneuvers. Reproduction of familiar radicular pain, as in the straight-leg raising, Lasegue, and crossed straight-leg raising tests, is highly suggestive of sciatic nerve root tension. Subsequent extension of the neck relaxes the spinal cord and may thus relieve nerve tension (see Fig. 9-28F).

 

FEMORAL NERVE STRETCH TEST

As noted, the straight-leg raising test and its variants do not place significant tension on the nerve roots above L5. Although compression of the upper lumbar nerve roots is not common, it does occur. Herniations of the L3-L4 disk commonly compress the L4 nerve root. The femoral nerve stretch test is designed to assess compression of the L2, L3, or L4 nerve roots. To perform the femoral nerve stretch test, the patient is positioned prone on the examination table with the knee flexed to at least 90°. The patient's hip is then extended passively by lifting the thigh off the examination table (Fig. 9-29). In the normal patient, this induces only a mild feeling of tightness in the anterior thigh. When one of the nerve roots that contribute to the femoral nerve is compressed, this maneuver reproduces the patient's radicular pain in the anterior thigh.

 

Miscellaneous Special Tests

SINGLE LEG HYPEREXTENSION TEST

It has already been noted that hyperextension of the lumbar spine is often painful in the presence of spondylolysis. The single leg hyperextension test has been described as a more specific test to detect the presence of spondylolysis and to suggest which side is involved in the

 

 

 

 

Figure 9-27. A and B, Bowstring sign.

 

 

 

 

Figure 9-28. A-F, Slump test

 

process. To perform the single leg hyperextension test, the patient is asked to stand in the straddle position with one lower limb extended behind the other. The patient is then instructed to lean back as far as possible, and the examiner assists the patient in achieving the maximal hyperextension of the spine possible without falling over

(Fig. 9-30). The procedure is then repeated with the position of the lower limbs reversed. In the presence of unilateral spondylolysis, hyperextension tends to exacerbate the patient's pain and the pain tends to be more severe when the lower limb on the affected side is extended posteriorly.

 

 

 

Figure 9-28, cont'd.

 

VALSALVA'S MANEUVER

The Valsalva maneuver is designed to increase intrathe-cal pressure and therefore exacerbate pain that is due to pressure on the spinal cord or its nerve roots. To perform the Valsalva maneuver, the patient is instructed to bear down as if attempting to have a bowel movement (Fig. 9-31). If pain is present owing to pressure on the spinal cord or the nerve roots, this maneuver usually exacerbates the pain. Pain from other causes should not be affected by the Valsalva maneuver.

Nonorganic Signs of Waddell

Waddell's nonorganic signs, already discussed in Chapter 8, Cervical and Thoracic Spine, were actually originally described in conjunction with the lumbar spine. They are helpful signals to alert the examiner to the possibility of

 

 

 

 

 

 

 

Figure 9-29. Femoral nerve stretch test Figure 9-30. Single leg hyperextension test.

360 CHAPTER 9 Lumbar Spine

 

 

 

 

 

Figure 9-31. Valsalva's maneuver.

 

nonorganic pathology or organic symptoms that are being enhanced by nonorganic factors.

 

Examination of Other Areas and Systems

Pain due to lumbar spine pathology frequently radiates to the pelvis, the posterior hip, or the thigh. In the case of lumbar disk disease, back pain may sometimes be completely absent, with the patient sensing pain only in the sciatic notch and the posterior thigh areas. Patients with this clinical picture often believe that they have a painful hip joint or a hamstring -strain. Complete investigation of potential lumbar spine pathology, therefore, often includes evaluation of the sacroiliac joint, the sacrum and the pelvis, the hip joint, and the thigh. The details of these related examinations are described in Chapter 5, Pelvis, Hip, and Thigh.

Because the symptoms of claudication due to peripheral vascular disease are similar to those of pseudoclaudi-cation associated with spinal stenosis, an examination of the peripheral circulation of the lower extremities is often a necessary adjunct to the lumbar spine examination. Finally, the examiner must always remember that

pathology of the abdomen or the retroperitoneum may present with back pain and must be alert for symptoms or signs that might indicate a disease process in one of these areas.

The physical findings in common conditions of the lumbar spine are summarized in Table 9-2.

 

 

 

PHYSICAL FINDINGS IN COMMON CONDITIONS OF THE LUMBAR SPINE

 

Herniated Lumbar Disk (Herniated Nucleus Pulposus)

Reproduction or exacerbation of sciatic symptoms with nerve tension tests (straight-leg raising, Lasegue's lest, slump test, bowstring sign)

Reproduction of sciatica with flexion of the lumbar spine Reproduction of sciatica with crossed straight-leg raising test (highly

specific)

Sciatic notch tenderness

Lumbar muscle spasm or list away from the involved nerve root (variable)

Neurologic deficit in the distribution of the involved nerve root

(variable)

Exacerbation of pain by Valsalva's maneuver

Spinal Stenosis

Loss of normal lumbar lordosis

Passive spine extension reproduces leg symptoms Sciatic notch tenderness

Motor or sensory deficit (variable)

Abnormal straight-leg raising test (infrequent)

Spondylolysis

Lumbar tenderness at the level of involvement (variable) Decreased lumbar lordosis (variable)

Hamstring tightness with straight-leg raising test

Pain exacerbated by hyperextension of the lumbar spine (passive extension, active extension, single leg extension test) (frequent)

Signs of associated spondylolisthesis, if present

Spondylolisthesis

Signs of spondylolysis (see above)

Visible or palpable lumbar step-off (more severe cases) Sciatic notch tenderness (variable)

Motor or sensory deficit (variable)

Lumbar Fracture

Tenderness at the level of injury

Localized swelling and hematoma or ecchymosis

Lower motor neuron deficit owing to injury to the cauda equina or the nerve roots (variable)

Upper motor neuron deficit if lesion above the level of the cauda equina

Lumbar Spondylosis

Decreased range of motion

Pain exacerbated by motion (variable) Localized or diffuse tenderness (variable)

Low-Back Strain

Paraspinous muscle tenderness Paraspinous muscle spasm (variable) Symptoms exacerbated by forward flexion List (variable)

Normal neurologic examination

CHAPTER 9 Lumbar Spine 361

 

 

TAKE HOM E POINTS

 

1. Lumbar spine examination should include careful inspection, gait, range of motion testing, and a thorough neurologic examination.

2. Palpation of the lumbar spine should be performed to identify any areas of tenderness or "step-off."

3. Neurologic examination should include motor, sensory, and reflex testing in the distribution of the lumbar nerve roots.

4. Nerve tension tests are helpful at identifying pressure on a nerve root such as that caused by a herniated disk. The straight-leg raising test is more sensitive for nerve root compression, while the crossed straight-leg raising test is more specific.

5. Profound or progressive neurologic deficit mandates immediate patient work-up.

 

• BIBLIOGRAPHY

 

Apley AG: A System of Orthopaedics and Fractures, 4lh ed. London, Butterworths, 1973.

Beetham WP, Polley HF, Stocurnb CH, Weaver VVF: Physical Examination Of the Joints. Philadelphia, WB Saunders, 1965.

Borenstein DG, Weisel SVV: Low Back Pain: Medical Diagnosis <\n<i

Comprehensive Management. Philadelphia, WB Saunders, 1989.

Breig A, Troup IDG: Biomechanical considerations in the straight-leg-raising test Spine. 1979;4:242-250.

Christodoulides AN: Ipsilateral sciatica on femoral nerve stretch test is

pathognomonic of an 1.4/5 disc protrusion. I Bone Joint Surg Br. 1989;71:88-89.

Deville WL, van der Windt AW, Dzaferagic A, lie/emer PD, Bouter LM:

The lest of 1-isegue. Spine. 2000;25:1140-1147.

Dyck P: The femoral nerve traction test with lumbar disc protrusion.

Surg Neurol. 1976:6:163 66.

Dyck P: Lumbar nerve root: the enigmatic eponyms. Spine. 1984;9:3-6. Ust ridge MN, Kouhe SA, Johnson NG: The femoral stretching test.

JNeurosurg. 1982;57:813-817.

Foerster O: The dermatomes in man. Brain. t933;56;I—39.

Forst || : Contribution a l.'F.tude Clinii|ue de la Sciatique. (thesis), Thes No. 33. Paris, 1881.

1 loppenfeld S, ed: Physical Examination of the Spine and Extremities, New York, Appleton-Century-Crofts, 1976.

Hudgins WK: The crossed straight leg raising test: a diagnostic sign of herniated dm . I OcCUp Med. 1979;21:407-408.

Inman VT, Saunders IB: The clinico-anatomical aspects of" the lumbosacral region. Radiology. 1942;38:669-678.

Keegan JJ. Garrett PD: The segmental distribution of the cutaneous nerves of the limbs of man. Anat Record. 1948;102:409-431.

Khuffash B. Porter RVV: Cross leg pain and trunk list. Spine. 1989; 14:602-603.

MacNab J: Backache. Baltimore, Williams & Wilkins, 1977.

McCombe PR Fairbank JC, Cockersole BC, Pynsent PB: 1989 Volvo Award in clinical sciences. Reproducibility of physical signs in low-back pain. Spine. 1989; 14:908- 918.

O'Connell JEA: Sciatica and the mechanism of the production of the clinical syndrome in protrusions of the lumbar intervertebral discs. Br | Surg. 1943;30:315-327.

Rothman RH, Simeone PA, eds: The Spine, 3rd ed. Philadelphia, WB Saunders.

Scham SM, Taylor TK: Tension signs of lumbar disc prolapse. Clin Orthop. 1971;75:195-204.

Schotlerman I, Zucherman J: History and physical examination. Spine State Art Kev. 1986;1:13-20.

Smith SA, Massie IB, Chesnut R, Garfin SR: Straight leg raising: anatomical effects on the spinal nerve root without and with fusion. Spine. 1993;18:992-999.

Spangfort EV: The lumbar disc herniation. A computer-aided analysis of 2,504 operations. ACTA Orthop Scand Suppl. 1972;142:1-95.

Supik LP, Broom Ml): Sciatic Tension Signs and Lumbar Disc Herniation. Spine 1994;19:1066-1069.

Thelander U, Fagcrlund M, Friberg S, Larsson S: Straight leg raising test versus radiologic size, shape, and position of lumbar disc hernias. Spine. 1992;17:395-399.

Troup |DG: Straight-leg-raising (SLR) and the qualifying tests for increased root tension. Spine. 1981;6:526-527.

Valllors B: Acute, subacute and chronic low back pain: clinical symptoms, absenteeism and working environment. Scand I Rehabil Med. 1985;11:1-98.

WisiK'ski K|, Garfin SR, Rothman RH: Lumbar disc disease. In Rothman RH, Simeone FA, eds. The Spine, 3rd ed. Philadelphia, WB Saunders, 1992.

Woodhall B, Hayes GJ: The well leg raising test of Fajersztain in the diagnosis of ruptured intervertebral disc. J Bone Joint Surg Am. 1930;32:786-79:.