subscapularis muscle

Introduction

Intrinsic (scapulohumeral) muscle of the shoulder, a tendon of which contributes to the rotator cuff.

Origin

subscapular fossa

Insertion

lesser tuberosity of humerus

Action

• rotates arm medially
• its tonic contraction helps to hold the head of the humerus in the shallow glenoid fossa

Innervation

• upper & lower subscapular nerves from posterior cord of the brachial plexus (C5, C6)

More general terms

• skeletal muscle (voluntary muscle)