By Joseph G. Werner, Jr., M.D.
percent of Western adults can expect to suffer a backache that temporarily
interferes with normal activity.1 At any point in time,
7% of Americans will have backache persisting for at least two weeks,
and 12% of those with backache will have sciatica.2 Backache
is second only to upper respiratory infection as a cause of absenteeism
among American workers, and it is our leading cause of work-related
The primary care specialist is usually the first to see and treat these patients, most of whom never require surgical consultation. Obtaining an adequate history is paramount, because the diagnosis of backache is far-reaching. This may be a subject for further discussion. I would like to offer the following physical examination (Table 1), which I have found expeditious in evaluating the young adult with acute backache, sciatica, or both. It is designed for the evaluation of adults aged 20 to 50 years who present with less than six weeks of backache, sciatica resulting from overuse or low-energy trauma, or both.
Physical Examination of the Young Adult Patient With
Backache, Sciatica, or Both
2. Inspection and Palpation
6. Straight leg raise
The patient should be asked to remove all clothing except for undergarments. This is essential for adequate examination of the back and lower extremities. Attempting to "work around" clothing or through nylons will serve only to compromise the accuracy of the examination and consume more of the physician's valuable time. We offer the patient a gown to preserve modesty and maintain comfort while awaiting evaluation.
The entire examination may be performed with the patient seated on an examination table. The legs should hang freely. The physician may perform the examination standing or sitting directly in front of the patient.
The first aspect of the physical examination is appraisal of the patient's demeanor. Distress may be assessed by facial expressions and body language. The demeanor may be assessed throughout the entire examination. The physician should note expressions and reactions to subsequent physical tests.
INSPECTION AND PALPATION
Inspection and palpation of the lumbar region is performed next. The examiner may appreciate paraspinal muscle spasm and make a note of its extent. The patient's general posture and spinal alignment may be grossly assessed as well. Cutaneous changes should be noted. There is little evidence to suggest that inspection and palpation of the lumbar spine will contribute to the diagnosis and treatment of acute backache and sciatica. The patient, however, may be reassured by including this as part of the examination.
Reflexes are assessed at this time, and note should be made of their symmetry and extent. The patellar tendon reflex tests the L4 nerve root. Achilles tendon reflexes are reflective of S1 nerve root function. The L5 nerve root may be tested by posterior tibial tendon reflex, but this reflex is frequently difficult to obtain even in normal patients. It may be omitted from the examination.
Sensation may be tested by light touch at teach of the indicated areas (Figure 1). L4 is assessed by palpation of the medial leg. L5 sensory function is assessed at the first web space, and S1 sensory function is assessed at the lateral aspect of the foot. Again, one looks for asymmetry between opposite limbs and ipsilateral dermatomes.
Assessment of motor function begins at the feet (pedal pulses may be assessed at this time but are routinely included only if the differential diagnosis of vascular claudication is being considered). Motor strength is assessed and graded on a scale of zero to five.
Muscle Strength Grading
Motion against gravity with full resistance
Motion against gravity with some resistance
Motion against gravity
Motion against gravity eliminated
Evidence of slight contractility
No evidence of contractility
First, L5 motor function is assessed by extensor hallucis longus extension. The patient is asked to lift the great toe toward the ceiling against the examiner's resistance. Next, S1 motor function is reflected in the gastrocnemius muscle. The patient is asked to "push on the gas" against the examiner's hand. Finally, quadriceps function, a reflection of the L4 motor nerve root, is tested against resistance. The patient is asked to extend the leg. For a patient with acute sciatica, this is frequently painful, and for this reason the motor function of the quadriceps group is the last to be examined.
STRAIGHT LEG RAISE TEST
Straight leg raise testing is performed next. This may be accurately performed with the patient remaining in the seated position. Extension of the knee in this position produces sciatic nerve tension by the same geometrical arrangement as when the patient is in the supine position. A positive finding is indicated by reproduction of the pain radiation or sciatica by the straight leg raise test. Back pain may be elicited in this manner but is not considered a positive tension sign.
Lesions at the conus medullaris or high lumbar region may show mixed upper and lower motor neuron findings. For this reason, clonus is tested in each ankle to complete the examination.
The physical examination described above offers a concise means of evaluation of the neurologic function and regional lumbar findings of the patient with backache, sciatica, or both. This basic examination may be performed in approximately one minute. X-rays of the lumbar spine may be obtained at the discretion of the examiner. For these patients, however, x-rays are unlikely to yield useful information and need not be obtained routinely at the primary visit. Upon completion of the physical examination, the patient is allowed to dress in privacy, after which I return to discuss my findings and recommendations. This arrangement provides the optimum of adequate exposure for thorough and rapid physical examination, as well as necessary comfort and modesty for questions and discussion.
1. Nachemson AL. The lumbar spine: an orthopaedic challenge. Spine 1976;1:59.
2. Deyo RA, Loeser J, Bigos S. Herniated lumbar intervertebral disc. Ann Intern Med 1990;112:598-603.