Impingement syndrome is an overuse injury that results in pinching of a rotator cuff tendon within the shoulder joint.
This shoulder condition is usually characterized by complaints of a dull aching on the front and outside of the shoulder, with pain that can on occasion extend to the elbow.
Sleeping on the injured shoulder is painful, and when raising the arm overhead, the pain can be sharp and stabbing in nature. Impingement syndrome is common in individuals participating in sports involving repetitive overhead movements such as swimming, tennis and baseball.
It is also often seen in occupations requiring arm movements above the head. Dry-wallers and electricians in particular are prone to this injury, but any of our islands’ home do-it-yourselfers are at risk. These activities may cause a repetitive strain injury to the muscles surrounding the shoulder, leading to faulty joint motion and compression on tendons in the shoulder, resulting in impingement syndrome.
The shoulder joint is a ball-and-socket articulation like the hip, only much shallower than the hip.
It is this shallow architecture of the shoulder that allows for the incredible range of motion of the shoulder. However, the shallow nature and large range of motion of the joint can create problems with stability.
The stability of the shoulder joint is maintained by four muscles that make up the rotator cuff. These four muscles travel from different parts of the shoulder blade (scapula) and attach to the arm (humerus). In addition to the rotator cuff muscles, the deltoid muscle also attaches at one end to part of the scapula (the acomium process) and attaches at the other end to the arm.
The deltoid muscles job is to help raise the arm, but in doing so it can distort the ball-and-socket joint of the shoulder. This distortion can cause the ball of the humerus to be pulled upwards higher than the socket. The rotator cuff muscles hold the humeral head in place, off-setting the powerful pull of the deltoid muscle.
There is a ‘tunnel’ in the shoulder joint, the suprahumeral space, which is the space between the top of the humerus, and the rest of the shoulder bones. One of the rotator cuff muscles (the supraspinatus) and one of the bicep tendons pass through this suprahumeral space.
Weakness of one or more of the rotator cuff muscles may lead to abnormal upward movement of the humeral head, decreasing the suprahumeral space and put pressure on the tendons, causing pain.
The injury may vary from mild inflammation to involvement of most of the rotator cuff. When the rotator cuff tendon becomes inflamed and thickened, it may get trapped under the acromion. Squeezing of the rotator cuff is called impingement syndrome.
Chiropractic therapy to treat impingement syndrome often consists of:
• Adjustments to the scapulothoracic joint, glenohumeral joint, and cervical spine to create normal joint motion.
• Acupuncture to restore normal muscle tone, decrease pain, and enhance healing.
• Specific muscle work to the rotator cuff and surrounding musculature of the scapula and humerus to free up soft tissue motion and break up adhesions.
• Shoulder rehabilitation routine to increase strength of the shoulder musculature.