The Shoulder and Why it Hurts
By: Dale J. Buchberger, PT, DC, CSCS, DACBSP
The shoulder is a remarkable mechanical invention. It is designed to allow for incredible range of motion while still maintaining its structure and stability. It is a “ball and socket” joint. The ball is the top of the upper arm or humerus and the socket being the lateral edge of the scapula or shoulder blade. The joint is held together by the joint capsule and supported by thickened regions of the capsule or ligaments. An ovoid ring of cartilage called the labrum deepens the socket. This is supported by four dynamic structures called the rotator cuff muscles (although incorrect it is not uncommon for them to be referred to as the roto-cup or rotor-cup). The last layer is the outer most layer of muscles that actually move the shoulder.
Because of this precarious balance of range and stability it has been said that the shoulder needs to be loose enough to function but tight enough to stay together. This is not only a problem in athletes that participate in “shoulder dominant” sports; it is also problematic for the general population. The general population is probably at more risk of injury to the shoulder because less focus is placed on maintaining strength and flexibility as a matter of routine. While aging is inevitable and trauma unexpected; slowing the aging process and improving the ability to withstand the forces of trauma is a choice. However, it is difficult to make the choice if we don’t have the information.
Trauma is relatively easy to explain. If we fall on an outstretched arm several things can happen. The shoulder joint can dislocate meaning the ball has come out of the socket and has to be put back in by a medical provider. The ball can “sublux” meaning the ball slipped out and went back in by itself. During the course of the dislocation or subluxation the bone or cartilage can fracture or tear. It is not unusual to experience a rotator cuff tear during one of these injuries. And like it or not the older we get the more susceptible we are to a rotator cuff tear. After an injury such as these the faster you get to a medical provider and have them evaluate your injury the more efficient your diagnosis and treatment will be. If the injury did not cause a tear or fracture there is a good chance that surgery can be avoided. Unfortunately if a tear has occurred surgery may be the most efficient route to a satisfactory recovery.
There are a large number of disorders that can occur in the shoulder that are not traumatic in origin. These can be age related, athletically related, genetically predisposed and some can be the result of overuse activities. Age related disorders are usually degenerative in nature. Common terms are bone spurs or arthritis. The problem with “arthritis” is that it is rare for any two cases to present the same. Just because your neighbor or your Aunt Betty had “arthritis” it doesn’t mean you have the “same” problem. No offense to Aunt Betty, but I don’t recommend taking medical advice from her unless she is a retired orthopedic surgeon. Bone spurs due to arthritis can manifest in different areas with a variety of outcomes. If the top part of the joint or acromioclavicular joint becomes arthritic it can result in impingement syndrome and eventually lead to a rotator cuff tear. These are the tears that occur when “I don’t know how it happened”. Basically the spurring acts like sandpaper and gradually wears the tendon down like a hole in the knee area of your jeans. Tendons can age without spurring. This is called tendinosis and occurs from either disuse or overuse. Poor diet will also contribute to tendinosis. Tendinosis must be treated more aggressively than tendonitis.
Younger individuals and athletes that participate in repetitive overhand sports such as swimming, baseball, tennis, etc. may experience impingement syndrome secondary to very subtle instability. This instability is the result of the joint capsule being loose and the rotator cuff and scapular muscles not being strong enough to position and/or support the shoulder joint for optimal stability. Many younger individuals and their parents may not be aware of available shoulder maintenance programs that can help to prevent injuries in these young athletes. Fortunately many of these sport related injuries are treatable through comprehensive rehabilitation programs. The bad news is that many athletes don’t find out about the programs until they have been injured.
The shoulder is the most complex joint in the body. If your shoulders begin to limit your activity or worse yet give you trouble sleeping, it is time to have a professional look at them and provide you with a skilled opinion. Just because Aunt Betty makes a mean cookie doesn’t mean you should get your medical advice from her.