The rotator cuff is the reinforcing structure which surrounds the shoulder joint. It is composed of four muscle tendons which merge together to form a fibrous capsule which helps to keep the ball of your upper arm in the socket of the shoulder. Injury to the rotator cuff is common as the shoulder is one of the most unstable joints in the body. Damage can be caused by falling, lifting or through repetitive actions such as stocking shelves higher than the shoulder or using a high-powered movement to swing a driver.
A chronic injury is one that develops gradually over an extended period of time, displaying few changes and an obvious pattern of progression. Chronic rotator cuff injuries are most commonly found among those who spend a great deal of time reaching overhead, for example house painters or welders. Most people tend to favor one arm over the other when working and, as a result, the shoulder structure on the dominant side changes slightly, creating a reduction in the attachment area of the collarbone. Chronic rotator cuff injury generally begins as an ache in the dominant arm, though in golfers the opposite seems to be true as a result of strong pull-though action during game play. In many cases, the pain increases at night, making it difficult for the injured party to rest. As the discomfort becomes more pronounced, the individual experiences increasing muscle weakness and difficulty using the arm. With time it will become a struggle to extend the injured arm to the side of the body or to lift it higher than the shoulder.
Acute rotator cuff injuries are those that develop suddenly, generally as the result of an accident such as a fall in which the injured party lands directly upon the shoulder or in conjunction with a trauma such as shoulder dislocation. In many situations, the afflicted party will feel an excruciating tearing sensation in their upper arm, followed immediately by severe throbbing throughout the joint. Upon examination of the injury site, they will most likely find their range of motion is extremely limited as efforts to move the arm are agonizing. There is generally a specific site of muscle tenderness directly over the tear that may be swollen, warm to the touch and slightly discolored. With time the injured party may experience muscle atrophy and weakness in the arm, which is due, in part, to the discomfort that accompanies limb usage. Additionally, there may be an audible cracking sound when the shoulder is manipulated into certain positions.
Rotator Cuff Tendonitis is a condition in which the tendons of the shoulder are inflamed and swollen, causing mild but ongoing shoulder discomfort. Also known as swimmer's shoulder, tennis shoulder and golfer's shoulder, the condition develops as the result of moving the arms over the head or swinging them repetitively and is therefore more commonly found among active participants in certain sports. Those who suffer with this condition will develop pain in the shoulder and arm when attempting these movements and will frequently find the afflicted joint uncomfortable at night, particularly if they attempt to sleep on it. The muscles in the arm may weaken slightly over time and range of motion may be limited to some extent, but for the most part, the condition does not interfere with daily activities outside of sports.