- See:
Rotator cuff:
- Anatomy:
- origin: entire anterior surface of the subscapularis fossa;
- insertion: lesser tuberosity of humerus and capsule of shoulder joint;
- action:
- main action: glenohumeral head depressor;
- in certain positions allows extension, adduction and medial rotation of humerus at shoulder;
- stabilization of the glenohumeral joint;
- reversed origin insertion action:
- when humerus is stabilized, abducts inferior border of the scapula;
- synergists:
teres major,
pectoralis major, latissimus dorsi;
- nerve supply:
- upper & lower
subscapular,
C5,
C6;
- subscapular nerve arises most commonly from posterior division of upper trunk, rather than from the
posterior cord and therefore
contains fibers only from C4-
C6;
- in some pts (30%) subscapular nerve does arise from
posterior cord;
- Discussion: Surgical Dissection for Anterior Shoulder Reconstruction;
- w/ anterior dislocations the
subscapularis is displaced forward, which
creates traction injury to the
axillary nerve;
- nerve is tethered above by brachial plexus & below where it wraps around behind neck of humerus;
- during anterior shoulder reconstruction, the axillary nerve may be identified by passing a digit along anterior surface of
subscapularis until the nerve is
encountered at lower margin of subscapularis as the nerve passes inferior to articular capsule on its way to
quadrangular space;
- before an incision is made in
subscapularis, the arm should be externally
rotated to avoid damage to
axillary nerve & circumflex vessels;
Repair of recurrent anterior dislocation of the shoulder using transfer of the subscapularis tendon.
Release of the subscapularis for internal rotation contracture and pain after anterior repair for recurrent anterior dislocation of the shoulder.
Operative treatment of irreparable rupture of the subscapularis. JBJS. 79-A (5):722-31, 1997 May.
Repair of Tears of the Subscapularis.
The Subscapularis Footprint: An Anatomic Description of Its Insertion Site.
Pectoralis Major Tendon Transfers Above or Underneath the Conjoint Tendon in Subscapularis-Deficient Shoulders
