The shoulder plays a large role in many activities and sports such as swimming, golf, hockey, baseball, tennis and volleyball. Shoulder problems are common, frequently difficult to manage and often become chronic. They are typically overuse, inflammatory type lesions, such as tendonitis and bursitis. Occasionally capsule and muscle tears may occur. High impact activities and falls may cause fractures and dislocations.
The shoulder complex is made up of three bones, which are connected by muscles, ligaments and tendons: the humerus (upper arm bone), the scapula (shoulder blade), and the clavicle (collarbone). The humerus sits against the scapula and forms a ball and socket joint, called the glenohumeral joint. This type of joint allows a large range of motion in all directions. Because the “socket” of the scapula is fairly flat, there are several layers of muscles, ligaments, and connective tissue that help to hold the “ball” of the humerus in place.
There are four main muscles that help stabilize the glenohumeral joint. These muscles are collectively called the rotator cuff and are made up of the supraspinatus, infraspinatus, teres minor, and subscapularis muscles. These four muscles together provide dynamic stability of the shoulder during all ranges of motion. During powerful and rapid motions of the shoulder, these muscles provide intricate control and stability of this multi-axial joint complex. They work in conjunction with the more global, larger muscles such as the deltoid and upper trapezius. This is why many rehabilitation programs focus on the control, awareness, and strength of these smaller cuff muscles rather than general strengthening exercises initially.
Other structures at the shoulder include cartilage, capsule and bursae. Bursae are fluid filled “sacs” that help to decrease friction between two tissues. For example, the subdeltoid bursa protects the rubbing of the deltoid muscle against the humerus. Bursae can be a source of inflammation and pain if repetitive movements cause excessive friction, resulting in a bursitis.
Rotator Cuff Injuries
Rotator cuff tendonitis is an inflammation of one or several of the tendons of the rotator cuff muscles. Tendons attach the muscle belly to the bone. Over time, repetitive motions can cause micro-tears of the tendon and result in inflammation and pain. The supraspinatus muscle, which assists in abduction (lifting outwards) is the most commonly injured tendon. Overuse, muscle imbalances, age related degeneration, and repeated overhead motions can cause shoulder tendonitis. Neck involvement, such as a C5/6 disc lesion or degeneration, is always considered when evaluating shoulder pathologies.
When the tendon becomes inflamed, it thickens and swells. This can result in an impingement syndrome, where a tendon or bursa gets “pinched” between joints or other muscles during movement. Typically this involves the supraspinatus tendon, the subdeltoid bursa, or the long head of the biceps tendon. Pain is often felt in the upper arm rather than at the shoulder joint.
Further wear and tear of these tissues due to age, poor posture, poor movement patterns, and overuse can cause a rotator cuff muscle tear. Common symptoms of a muscle tear or tendonitis are pain with active movement, weakness, limited range of motion, and a catching sensation with lowering the arm.
Another common tendonitis in the shoulder involves the long head of the biceps muscle, bicipital tendonitis. This muscle sits in the front of the glenohumeral joint and extends down to the elbow. Symptoms may include pain with shoulder flexion, pain with elbow flexion, and local tenderness along the front of the shoulder.
Early intervention is important with shoulder injuries to prevent compensatory movement patterns. As the shoulder complex involves coordinated movement from the clavicle, scapula, humerus and the thoracic spine – it is important to address these factors early.
There are several barriers to the recovery of shoulder injuries that can contribute to the degeneration of the surrounding soft tissue structures. Repetitive and prolonged overhead activity can pinch both the supraspinatus and biceps tendons. This repeated compression can cause micro-tears in the tendons and restrict the blood supply to those structures. Further swelling and thickening can occur over time. The supraspinatus. in particular, has an inherently poor blood supply. This makes this structure even more susceptible to damage with repetitive use and overhead activities. A lack of activity, or deconditioning, can also be harmful. When there is pain with movement and one opts to rest and avoid aggravating positions – poor posture, muscle atrophy and weakness can occur that may further disrupt the mechanics at the shoulder joint. Frequent sleeping on the same side can also compress the joint and certain soft tissue structures over prolonged periods of time.
Poor posture is deleterious for most areas of the body! The shoulder and neck complex are commonly affected. Rounded shoulders, slouched posture, and the chin poked forward are commonly seen. This posture causes the neck to be compressed, especially at the C5/6 vertebrae, discs and nerve roots which innervate the shoulder area. The upper back and scapular muscles tend to lengthen and weaken, thus not contributing to the stability and proper movement pattern at the shoulder. The shoulder joint can “drift” forwards and stress the anterior shoulder muscles, which may cause tendonitis and impingement.
There are a variety of treatment options for acute and chronic injuries. Icing an acute injury for the first 48-72 hours can help reduce inflammation and pain. Avoiding overhead activity and limiting movement to pain free ranges initially can reduce the impingement (pinching) of certain structures. Gentle range of motion exercises, using pulleys, a cane or assistance from the other arm, can encourage circulation and reduce stiffness. Maintaining proper posture can reduce muscle imbalances and reduce stress on affected structures. Stand tall, relax the shoulders and slightly tuck the chin. Gradually progressing to strengthening exercises that incorporate the neck, upper back, chest and shoulders will help to create balance, awareness and coordination of this complex joint.
Rehabilitation of the shoulder can be a complex process. The longer an injury is allowed to continue without being treated, the more the body compensates, making recovery a longer process. As with all injuries, the sooner you seek treatment following an injury, the quicker the recovery and your return to the activities you enjoy.
Jennifer Gordon (BSc.PT, AFCI)
Physiotherapist
