Hi, how can you tell the differents between si joint dysfunction and piriformis sydrome. ?

Can be difficult...: Both can have similar symptoms: pain in the buttock, back of the thigh, difficulty putting weight down on that limb, nerve irritation from the sciatic nerve (pain, tingling down the leg). Physical exam stretching the piriformis can make the diagnosis and sometimes help it. Injection into the si joint can make si diagnosis. Physical therapy, antiinflammatory meds often help both.