The rotator cuff is a series of muscles and tendons that act upon the shoulder to help hold the ball into the socket and perform complex movements allowing us to move our arm.
The rotator cuff has four main tendons:
- Supraspinatus
- Infraspinatus
- Subscapularis
- Teres Minor
The long head of the biceps tendon is a tendon that also crosses or enters the shoulder between these muscles and may also be injured if the rotator cuff is injured.
The rotator cuff is separated from the point of the shoulder or the acromion by a small fluid filled sac called a bursa. Bursae are normal in all people however, if we have a rotator cuff injury or a spur on the point of the shoulder / acromion, we may get inflammation within this bursar called bursitis.
Injury or wear and tear to all of these structures within the shoulder can cause pain and disability and the inability to use the shoulder.
Because the shoulder is so mobile it can be susceptible to the ball jumping out of the socket – or a dislocation. When this happens the ligaments that hold the ball into the socket may be stretched or torn away from the bone and may require repair. Those ligaments are known as the glenohumeral ligaments.
There are two main joints around the shoulder, that connecting the clavicle to the scapular – the ACJ or acromioclavicular joint, and the one connecting the scapular to the humerus – the glenohumeral joint. Both of these joints may be affected by arthritis and become significant sources of pain within the shoulder region.
