The history and physical examination in patients with sciatica often provide characteristic findings depending upon which nerve root is involved (see Table-4)
The general physical examination can be as important as the neurological examination, and should include the vasculature (especially the pedal pulses), abdomen, hips, inguinal areas and rectum (especially if a cauda equina syndrome is suspected). The patient should be undressed.
Inspection of movement and Gait _ The way the patient moves, sits and stands provides useful information.
Signs of muscle weakness include atrophy (the calf and thigh circumferences should be measured, looking for asymmetry), fasciculations, pelvic tilt (the "bad" side is down)
Gait testing should include walking on heels and on toes Involuntary knee flexion (to guard against root traction) and scoliosis may be present. Cafe au lait spots, if present, may
Palpation : Palpation of the lower spine, paraspinal muscles, sciatic notches and sciatic nerve, may reveal tenderness, muscle spasms, and radiating pain. Muscle tenderness may be associated with nerve root irritation, affecting calf muscles with S1, anterior tibial muscles with L5, and quadriceps with L4.
Nerve root stretching : Roots may be impinged upon or tethered by herniated discs or other lesions, so that stretching the root causes pain. This should be tested by having the patient bend forward and by one or more of the tests of straight leg raising (SLR).
Straight leg raising _ SLR Lasegue's sign is performed with the patient lying flat on his or her back with the uninvolved knee bent 45 degrees, and that foot resting on the table. The involved leg is raised straight up, while the ankle is kept at 90 degrees of flexion. Disc herniation tends to tether the irritated nerve roots; as a result, stretching the nerve roots with SLR causes radiation of pain into the lower extremity.
Radicular symptoms - involving the leg and/or foot - are precipitated on the left with the straight leg raised to 45 degrees.
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