Musculus supraspinatus
The supraspinatus fills the supraspinous fossa above the scapular spine. It originates from the supraspinous fossa of the scapula and inserts on the greater and lesser tubercles of the humerus. Its actions are to extend the shoulder and stabilize the shoulder during weight bearing. It is innervated by the suprascapular nerve (roughly C6-C7). It is one of the two muscles affected in Sweeney (suprascapular neuropathy), the other being the infraspinatus.
Origin: Supraspinous fossa of the scapula
Insertion: Greater and lesser tubercles of the humerus
Action: Extends the shoulder; stabilizes the shoulder during weight bearing
Innervation: Suprascapular nerve (C6-C7)
Suprascapular nerve damage causes atrophy of the supraspinatus and infraspinatus, leading to shoulder instability and the characteristic Sweeney appearance. Diagnosis is clinical and with electromyography or ultrasound. Relevant in evaluations of shoulder function and after trauma.
## Overview Suprascapular neuropathy, traditionally called sweeney, is damage to the suprascapular nerve, usually from collision with a doorframe, post, or fence. The nerve supplies the supraspinatus
## Overview Supraspinatus tendinopathy is chronic strain or degeneration of the supraspinatus tendon where it inserts on the humerus. It is increasingly recognized with ultrasound as a cause of forel
Shoulder muscle atrophy or instability after trauma should be evaluated. Early diagnosis improves management options.
## Overview Suprascapular neuropathy, traditionally called sweeney, is damage to the suprascapular nerve, usually from collision with a doorframe, post, or fence. The nerve supplies the supraspinatus and infraspinatus muscles. Rapid atrophy makes the scapular spine prominent, and the shoulder may pop outward during weight-bearing. About 80 percent of horses improve with time, though some muscle loss often remains. ## Causes Trauma to the suprascapular nerve. ## Diagnosis Characteristic rapid muscle wasting and shoulder instability. Electromyography can confirm denervation. ## Treatment Rest and time. Surgery (scapular notch resection) is occasionally performed for chronic cases. Most improve without surgery. ## Recovery and Prognosis Good for functional recovery in the majority. Full muscle mass may not return. Recovery can take up to 12 months. ## Prevention Safe stable design that reduces shoulder collisions. Signs include: rapid muscle wasting above and below the scapular spine; prominent scapular spine; shoulder pops outward; stumbling; circumduction
## Overview Supraspinatus tendinopathy is chronic strain or degeneration of the supraspinatus tendon where it inserts on the humerus. It is increasingly recognized with ultrasound as a cause of forelimb lameness. Signs include intermittent lameness, pain on palpation over the point of the shoulder, and reduced stride length, often worse on hard ground. ## Causes Repetitive overload. ## Diagnosis Ultrasound of the supraspinatus insertion and diagnostic analgesia. ## Treatment Rest, controlled exercise, and ultrasound-guided injection (corticosteroid, platelet-rich plasma, or other biologics). ## Recovery and Prognosis Fair to good with appropriate management. ## Prevention Progressive conditioning. Signs include: intermittent forelimb lameness; pain on palpation over the point of the shoulder; reduced stride length; worse on hard ground
Suprascapular nerve damage causes atrophy of the supraspinatus and infraspinatus, leading to shoulder instability and the characteristic Sweeney appearance. Diagnosis is clinical and with electromyography or ultrasound. Relevant in evaluations of shoulder function and after trauma.
Shoulder muscle atrophy or instability after trauma should be evaluated. Early diagnosis improves management options.
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