
Subscapularis Muscle
Origin: Medial two-thirds of volar surface of the scapula
Insertion: Lesser tubercle of the humerus
Actions: Internally rotates humerus
Innervation: Upper and Lower Subscapular Nerve (C5, C6)
Blood Supply: Subscapular artery from the axillary artery
Primary Actions of the Subscapularis
1. Internal rotation of the arm at the shoulder
Agonists:
- Deltoid (anterior)
- Pectoralis Major
- Latissimus Dorsi
- Teres Major
Antagonists:
- Infraspinatus
- Teres Minor
- Deltoid (posterior)
Advertisement
Secondary Actions of the Subscapularis
1. Assists with depression of the humeral head
Agonists:
- Infraspinatus
- Teres Minor
Muscle Pain Information: The subscapularis muscle contributes to pain in the front and back of the shoulder, the upper arm, and wrist.