supraspinatus

Intrinsic (scapulohumeral) muscle of the shoulder, a tendon of which contributes to the rotator cuff. Origin: supraspinous fossa of scapula Insertion: greater tuberosity of humerus Action: 1) initiates abduction of arm 2) its tonic contraction helps hold the head of the humerus in the shallow glenoid fossa Innervation: suprascapular nerve (C5, C6)

References

Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999