Subscapularis (left) (Musculus subscapularis)
Educational content only — not medical advice.
Anatomy
Fills the subscapular fossa on the costal (anterior) surface of the scapula; the strongest medial rotator and the only rotator-cuff muscle in front of the joint. The subscapular bursa separates it from the chest wall, letting the scapula glide freely over the ribs.
Origin & insertion
Nearly the whole subscapular fossa and its margins. Lesser tubercle of the humerus and the shoulder joint capsule.
Action
Medially rotates and adducts the arm and pulls the humeral head forward in the socket — the sole restraint to anterior translation.
Innervation
Upper and lower subscapular nerves (C5–C7).
Clinical notes
Injured by forced external rotation in accidents and sport; tested by the Gerber lift-off test; weakness opens the door to recurrent anterior shoulder dislocation.
Related structures
Educational references
FAQ
What is the role of the Subscapularis (left)?
Fills the subscapular fossa on the costal (anterior) surface of the scapula; the strongest medial rotator and the only rotator-cuff muscle in front of the joint. The subscapular bursa separates it from the chest wall, letting the scapula glide freely over the ribs.
Why is the Subscapularis (left) clinically important?
Injured by forced external rotation in accidents and sport; tested by the Gerber lift-off test; weakness opens the door to recurrent anterior shoulder dislocation.
Source & license
BodyParts3D, © The Database Center for Life Science licensed under CC Attribution 4.0 International (https://creativecommons.org/licenses/by/4.0/). license details