Supraspinatus Muscle - Attachments, Actions & Innervation
Infraspinatus Muscle – Attachments, Actions & Innervation
The infraspinatus is a thick and triangular muscle. It’s one of the Rotator Cuff muscles providing the mechanical link between the posterosuperior and anterior parts of the rotator cuff.
Attachments of Infraspinatus :Origin & Insertion
Origin: (proximal attachments)
a. Infraspinous fossa of the scapula.
Insertion: (distal attachments)
a. Middle part of the greater tubercle of the humerus.
Actions of Infraspinatus:
a. Laterally rotates the arm at the shoulder (glenohumeral) joint.
b. Helps stablize the shoulder by drawing the humerus toward the glenoid fossa of the scapula.
Innervation of Infraspinatus:
Nerve to the muscle:
a. Suprascapular nerve.
a. C5 and C6.