- Abductors of the Shoulder:
- Rotator cuff;
- origin: medial 2/3 of supraspinatus fossa above spine of scapula;
- insertion: superior surface of greater tuberosity of humerus and capsule of shoulder joint;
- demensions: supraspinatus averages 25 mm wide and has a medial-to-lateral footprint (tendon attachment)
of 12.1 mm at the midtendon
- action: abduction of humerus at GHJ: stabilization of glenohumeral joint;
- nerve supply: suprascapular, C4, C5
- synergist: deltoid;
- supraspinatus muscle contributes to GH stability, demonstrating peak activity in late cocking phase of throwing mechanics.
- overuse of supraspinatus & resulting fatigue can subject amateur athlete to shoulder injuries.
- the supraspinatus muscle is tested with the shoulder abducted 90 degrees, flexed 30 deg and then maximally internally rotated;
- downward pressure is resisted primarily by the supraspinatus
Exertional Supraspinatus Syndrome. A Report of Two Cases