ORIGIN

Anterior surfaces of the sacrum by three or four slips off the portions of bone between the foramina of the sacrum, the ilium near the posterior inferior iliac spine, the capsule of the sacro-iliac joint, and occasionally the upper part of the sacrotuberous ligament

 

INSERTION

By a rounded tendon to the upper part of the medial surface of the greater trochanter, occasionally blending with the common tendon of obturator internus, gemellus superior, and gemellus inferior

 

ACTION

Assists with lateral rotation and abduction of  the thigh

 

INNERVATION

Nerve to piriformis (S1, 2)

 

PRIMARY JOINT

Acetabular femoral joint

 

KEY STRENGTH TRAINING EXERCISES

Resistance band abduction

Hip extension exercise

 

NEW STRENGTH TRAINING EXERCISES

Side lying clam exercise

 

COMMON INJURIES

Piriformis syndrome

Strain