Rotator Cuff Injuries
Anatomy: The rotator cuff is made up of 4 muscles. These include the supraspinatus M, infraspinatus M, subscapularis M and the teres minor M. In addition, there are synergistic muscles that also assist in movements of the shoulder such as the latissimus dorsi muscle and the deltoid muscle.
Biomechanics:
The shoulder joint is an inherently unstable joint only made stable by the above-mentioned rotator cuff muscles. These four muscles work in conjunction with each to secure the head of the humerus into the glenohumeral joint. When one of these 4 muscles become injured the whole structured becomes jeopardized. The shoulder is a diarthrodial joint meaning it is freely movable and can perform all of the following movements: Abduction, Adduction, circumduction, external rotation, internal rotation, flexion and extension. Each muscle has a specific role to play in the multi-directional movements made possible by the unique joint.
How Accurate are Shoulder Assessments?
Numerous shoulder assessment strategies exist that can isolate each muscle and determine where and what the injury may be. To illustrate here is a list of a few assessments:
- Hawkers-Kennedy test – Positive results indicate subacromial impingement or bursitis.
- Speed test – Positive test indicates damage to the long head of bicep tendon.
- Empty Can Test – Positive test is indicative of supraspinatus tear.
- Gerber’s test – Positive test indicates injury to internal rotators (subscapularis).
- An active/Passive range of motion.
- Upper Neural tension test – Positive results indicate damage to the nerves in the neck shoulder and arm.
How can Physiotherapy and Exercise Physiology Help?
Depending on the nature of injury initial resting may be required before manual therapy or exercise treatment can commence. Seeking your local GP is a great place to start to determine the extent of your shoulder injury. It is recommended you seek a Physiotherapist or Exercise Physiologist to develop an exercise program tailored to your needs to reduce any pain you may be experiencing and regain full movement of the shoulder.
