Shoulders are complex. The shoulder joint offers the most range of motion of any joint in the body, allowing us to perform activities that require tremendous force (such as climbing, throwing, bearing weight through the arms, and reaching for heavy things). It also has the fine motor control to reach for a glass, hold a paint brush, or hold a baby. Because of its wide range of motion available, the shoulder joint compromises on strength and stability, and is the most prone to dislocation.
The shoulder region has over 20 muscles that either cross the shoulder joint or attach to the scapula (shoulder blade) or clavicle (collar bone). This number does not include all of the joints and musculature involved with the neck, thoracic, and lumbar spine, which also moves or stabilizes during shoulder motion. When using the throwing motion as an example, the entire body of the player is involved with throwing a ball overhead. Everything has to be in good working order to complete that task safely and successfully.
Let’s say, for example, one of these structures is not performing as it should. Perhaps, the external rotators of the rotator cuff (i.e. teres minor and/or infraspinatus muscles) are weak, the serratus anterior is not stabilizing the scapula against the rib cage, or the anterior ligaments of the shoulder are loose. If one part of the shoulder complex is not optimally functioning, shoulder stability becomes compromised. The act of reaching overhead or reaching out away from the body would make the head of the humerus slide forward within the socket, making the shoulder vulnerable to injury.
One very painful injury, which frequently requires a lengthy rehabilitation, is a shoulder dislocation. The shoulder most often dislocates anteriorly and inferiorly, and occasionally will relocate by itself. Otherwise, the shoulder will need to be relocated by a doctor in the emergency room. Either way, it is a good idea to see a physician to determine the extent of damage to the shoulder from the dislocation. Early on, the shoulder should be immobilized in a sling and iced regularly to help control the inflammation. Your physical therapist will start having you perform safe range of motion and strengthening exercises to help restore normal shoulder movement and help improve your function to help avoid a future dislocation. Research has shown that if you have had one shoulder dislocation the risk for future dislocation within the next two years is at least 55%, with the recurrence rate being even higher if you are young in age. The high recurrence rate is secondary to tissue damage which has not fully healed prior to full activity return, or because the strength and motion deficits from the injury persist, leading towards faulty movement patterns and a higher risk for re-injury.
Your physical therapist will assess your shoulder and identify which muscles are weak, and what areas of the shoulder are lacking stability. Therapy typically begins with range of motion exercises and small isometric strengthening exercises. As your motion and strength improves, progression occurs with larger functional movements such as reaching, pushing and pulling.
The following are three frequently prescribed exercises to start activating the rotator cuff muscles. The patient lies on their back, with his/her shoulder and scapulae resting on the floor. After an injury it is common to guard the shoulder by shrugging it toward the ear and holding it forward. The key to doing these exercises right is to start in a neutral position, which laying on the back helps with initially.
External rotation: lie on your back with your affected arm by your side and elbow bent 90 degrees. With the palm of the hand facing the body, push the back of your hand against a piece of furniture, keeping your elbow resting near your hip. You should feel the muscles tense behind your shoulder. Comfortably hold 5 seconds, and then relax. Repeat 15 times, 3x/day.
Internal rotation: Lie on your back with your affected arm by your side and elbow bent 90 degrees. Use your other hand as resistance, and attempt to push the palm of your hand towards your belly. You should feel the muscles in your arm-pit tense. Avoid using the pecs (the muscles in the front of your chest, and avoid lifting the back of your shoulder off the floor. Hold for 5 seconds, and then relax. Repeat 15 times, 3x/day.
Scapular retraction: Either lie down in your back or sit up with something behind you such as the wall. Squeeze your shoulder blades together. Use the floor or the wall to make sure that your shoulder blades are flat against your rib cage. Hold for 5 seconds, and then relax. Repeat 15 times.
These exercises provide a good starting point for you. Correct usage of these muscles is imperative to performing more complicated shoulder movements. You can expect healing time for a shoulder dislocation to be at least 3-6 months, when proper rehabilitation has occurred. With the high incidence of the recurrence of shoulder dislocation, it is worthwhile to appreciate the appropriate rehabilitation time before returning to your normal activities.