Infraspinatus muscle
| Infraspinatus muscle |
|---|
|
| Shoulder muscles with infraspinatus muscle (8) |
| origin |
| Infraspinate fossa of the scapula |
| approach |
| Greater tuberosity or infraspinate muscles of the humerus |
| function |
| Adduction , abduction and external rotation of the arm |
| Innervation |
| Suprascapular nerve |
| Spinal segments |
| C5, C6 |
The infraspinatus muscle ( Latin for "lower bone") is one of the shoulder muscles of the upper arm . It is partially covered by the deltoid muscle . Together with the supraspinatus muscle , the teres minor muscle and the subscapularis muscle , it forms the rotator cuff in humans , which holds the head of the humerus in the socket.
function
The infraspinatus muscle is responsible for abduction and adduction . The main task is the external rotation of the arm.
In quadruped mammals, outward mobility is clearly restricted in the shoulder joint, so that only flexion and extension are possible here. In addition to flexing the shoulder joint, the infraspinatus muscle acts as an elastic collateral ligament and prevents the shoulder joint from dodging sideways.