Rotator Cuff Research Paper

The rotator cuff is a group of four muscles that envelop the shoulder joint to connect the humerus to the scapula and allow movement of the joint. (5) The four muscles are: the supraspinatus, the infraspinatus, the teres minor, and the subscapularis. (1)

The supraspinatus is located above the scapular spine on the posterior of the scapula and attaches to the supraspinous fossa on the scapula (10). The infraspinatus is below the scapular spine and attaches to the infraspinous fossa on the scapula (11). The teres minor is found on the lateral border of the scapula (9). The supraspinatus, infraspinatus, and teres minor also share a common tendon attachment in the intertubercular groove of the humerus. The subscapularis is located between the

Grade I injuries involve a straining the muscle fibres without tearing the muscle, such as tendinitis, which is inflammation of the tendons of the rotator cuff muscles as a result of repetitive minor injury, or overuse (3). Grade II injuries involve a partial tear of a muscle, which damages the tissue but does not result in a complete separation of the muscle (5). Grade III injuries are full width tears which separates the muscle into two parts (5). Because the three of the four muscles share a common attachment point, if one muscle is injured, the rotator cuff won’t be able to function properly.

Causes

Rotator cuff tears are often caused by normal activity (5). They are especially common in people whose jobs involve a lot of overhead lifting, like painters or carpenters, and in athletes involved in sports that require a lot of throwing or overhead motions (2). Some common sports that cause injury to the rotator cuff include baseball, tennis, swimming, kayaking, golf, and cricket (4). These injuries are the result of some form of trauma to the shoulder area, but there are many different causes, which can lead to different degrees of

Common causes are bone spurs and repetitive stress on the rotator cuff. Bone spurs are caused by an inflammation of the surrounding tissue, which triggers the osteoblast, or bone building cells, to build more bone in the area (6). This can lead to a sharp spine on the bone, which will rub against the muscle and can eventually start to cause a tear (6). Grade II injuries are also commonly caused by repetitive motion putting stress on the muscles (5). This is especially common in people who do a lot of overhead lifting (3). Chronic injuries occur over a long period of time, so someone that has one may not notice it in the initial stages and won’t seek treatment until it becomes a serious injury.

Grade III Injuries

Grade III rotator cuff injuries result from a serious trauma to the shoulder. This type of injury involves a full thickness tear of a muscle (5). These injuries are usually acute, and are the result of a major injury, rather than a series of smaller injuries, which cause a tear over time. They commonly come from a fall directly onto the shoulder or lifting something heavy in an awkward position, but can also result from heavy pushing, heavy pulling, or a powerful throw (2). Grade III injuries can also be caused as a result of other injuries such as a fractured clavicle, and a separated or dislocated shoulder