In piriformis syndrome, which abnormality is most likely observed during evaluation?

• A. Increased stride length
• B. Functional leg length discrepancy
• C. Internal rotation of the lower extremity
• D. Increased lumbar lordosis

Answer: (B)

In piriformis syndrome, the most likely finding during evaluation is a functional leg length discrepancy. When the piriformis on one side tightens or goes into spasm, it can tilt the pelvis and alter stance alignment, making one leg appear shorter during standing or walking even though the actual bone lengths are the same. This functional discrepancy often accompanies the buttock/buttock-to-thigh pain pattern and altered gait seen with hip external rotator involvement.

Other options don’t fit as well because increased stride length isn’t a typical sign of piriformis involvement (pain and muscular imbalance more often shorten stride or change gait), internal rotation of the lower extremity isn’t usually increased (the piriformis is an external rotator, and tightness would more likely limit internal rotation or cause pain with it), and increased lumbar lordosis isn’t a specific, diagnostic observation for piriformis syndrome (lumbopelvic posture can vary without being a defining feature of this condition).