02/01/2026
Piriformis syndrome can occur in both shortened (overactive/spasmed) and lengthened (inhibited/stretched) states, irritating the sciatic nerve via compression or altered tension—aggravated by valgus collapse or anterior pelvic tilt in squats/running.
Shortened piriformis (most common)
Tight/spasmed from sitting/overuse; limits internal rotation, hurts palpation/sitting, eases with stretch/smashing but flares with strengthening.
Compresses sciatic (deep, piercing in 15–16%, split above/below in others), causing gluteal pain radiating to thigh/calf, worse prolonged sitting.
Lengthened piriformis
Sloppy mechanics (knee valgus, APT) stretch/inhibit it, causing opposite symptoms: pain with hip extension/abduction, limited external rotation, improves with strengthening but flares stretching.
Lax muscle allows sciatic glide issues or secondary glute med weakness, mimicking deep glute pain.
Symptoms (one-sided posterior hip)
Buttock tenderness + radiation (glutes → leg/calf); numbness/tingling.
Short: FAIR test+, sitting aggravates. Long: stance/running hurts.
Anatomic variants (sciatic piercing piriformis 15%) raise risk—treat cause (glute activation for valgus) over symptoms for lasting fix.