By: Dale J. Buchberger, PT, DC, CSCS
Shoulder pain will affect as many as 70% of the population at some point in their life. Approximately 40-50% of which will persist and last longer than one-year. The most common causes of shoulder pain in primary care are reported to be rotator cuff disorders, acromioclavicular joint disease and glenohumeral joint disorders. The uniqueness of the shoulder joint complex is what results in the majority of shoulder disorders when they are not well maintained. Primarily the balance of range of motion with the necessary strength required to keep the joint structure stable.
Because of the vast interaction of tendons and ligaments that maintain the stability and function of the shoulder complex, there are many causes of shoulder pain. While the rotator cuff is a commonly affected collection of tendons and muscles in the shoulder it is not the only thing that can generate pain in the shoulder. Not only are there a variety of tissues that can be damaged or injured but various, tissues can be specifically affected by age.
The joint formed where the collarbone or clavicle meets the top of the shoulder blade or scapula is called the acromioclavicular joint. This joint can be injured through traumatic events such as falling off of a bicycle or slipping and falling on the tip of your shoulder. The acromioclavicular joint can become degenerated or arthritic through overuse mechanisms such as bench-pressing heavy weights or performing overhead activities for a long period of time. According to one study, 93% of people over the age of 30 will have degenerative changes in the acromioclavicular joint.
The rotator cuff is probably the most commonly affected group of tendons in the shoulder. Like the acromioclavicular joint, it can be affected by overuse problems and traumatic problems. If you fall with your arm outstretched and you are over the age of 30 there is a good chance that you will tear the supraspinatus portion of the rotator cuff. If you are over the age of 60 there is a good chance that you will also tear the subscapularis portion of the rotator cuff. Younger individuals can experience impingement syndromes that cause compression of the rotator cuff. If gone untreated the increasing rotator cuff weakness associated with the impingement can eventually lead to a tear of the rotator cuff.
The shoulder joint is a ball and socket joint much like the hip joint. Because the shoulder joint has more mobility than the hip joint, the socket is shallow. In order to improve the structural stability of the joint the socket has a ring of cartilage around it called the labrum that increases the depth of the socket. Unfortunately, this ring of cartilage can be a source of pain. The labrum is commonly torn when someone falls on an out stretched arm, dislocates their shoulder or is involved in repetitive overhand activities such as throwing a baseball or lifting heavy weights. There are many classifications of labrum tears and many but not all of these may require surgical repair.
The ligaments that attach the ball to the socket in the shoulder joint can also develop or acquire their own set of specific disorders. The main job of the ligaments or capsule is to hold the ball and socket together at extremes of range of motion. Unfortunately, both genetics and activities may result in the capsule becoming too loose. This is known as instability. There are many grades of instability. The lowest grade results in a painful shoulder usually in a younger individual. The highest grade would result in recurrent spontaneous dislocations of the shoulder. Sometimes a rigorous strengthening program of the various shoulder muscles can remedy the instability. In the more severe cases, surgical tightening is required. The other perspective on the capsule is when it becomes too tight. A severely tightened capsule is known as a Frozen Shoulder or adhesive capsulitis. This is very common in patients with Type-1 and Type-2 diabetes and usually occurs without any known mechanism. Some patients that experience a tight shoulder capsule after surgery or an injury are in for a complex road of physical therapy. The protocol for recovery from a tight shoulder must be adhered to until recovery. Failure to follow the protocol or the advice of the medical team is a sure path to a prolonged recovery. Large gaps in treatment will result in set backs and a large degree of frustration on the part of the patient and the members of the medical team.
The shoulder is the most complex joint in the body. If your shoulders limit your activity or disrupt your sleeping habits, it is time to get a professional opinion. Freelancing your treatment with the Internet and various fitness magazines as your resource is a recipe for disaster and frustration.