by 
James Modera, P.T. & Dr. Kathryn Friday Scibona, D.P.T.
You reach into your top cupboard to get a glass and feel a sharp pain in the top of your shoulder as you reach in. Working overhead for short periods fatigues your shoulder quickly. These are signs of impingement syndrome. Shoulder impingement is a common cause of pain for many people. Shoulder impingements interfere with people’s ability to perform daily activities such as their jobs, sports, personal hygiene, recreational and household activities. If left untreated, shoulder impingement may lead to more serious conditions that require surgery. When treated appropriately, physical therapy can eliminate pain and restore full function.
An impingement in the shoulder occurs when the rotator cuff tendons and/or bursa are pinched between the bones in the shoulder joint causing pain, inflammation and damage. In a shoulder with an impingement, the humerus (the large bone in the upper arm) shifts in an upward direction and sandwiches the mentioned structures between itself and the Acromion (roof of the shoulder), as you lift your arm up in front or to the side. Shoulder impingements are caused by various factors including anatomy, predisposing factors like limited flexibility, rotator cuff weakness, arthritis, trauma and poor posture.
A narrowing in the shoulder joint either caused by bone spurs or arthritis irritates the soft tissue in the shoulder. As you raise your arm the teeth-like projections from arthritis inflame bursa and pierce the rotator cuff. Certain occupations like linesmen and carpentry require movements which narrow the joint space and cause an impingement. Repetitive, overhead movements like painting may also cause an impingement.
Poor posture results in cumulative trauma which can be an origin for an impingement. Poor posture can shift the acromion forward and down. This posture paired with limited flexibility can position the top of the humerus on the rotator cuff eliciting constant pressure which is worsened with movement. Slouching through the upper back and rounding of the shoulders are the common postures which lead to shoulder impingement. Eventually people with poor postures may begin to experience a dull ache in their shoulders or upper arm after overhead work or even driving a car.
Initially, it is important to rule out other causes of shoulder pain which are not directly related to an impingement such as referred neck pain. The neck may also cause pain in the shoulder similar to an impingement. Overuse of the upper trapezius muscles and other muscles attaching from the neck may occur due to a lack of function in the shoulder. The ensuing pain from the neck can co-contribute to the overall pain in the region.
Once a proper diagnosis is made your physician may order Physical Therapy to treat the symptoms and causes of a shoulder impingement. After an evaluation the physical therapist will prescribe an exercise program specifically based on observed patterns of joint capsule tightness and muscle weakness. A common and safe exercise is the shoulder pendulum. To perform this exercise, lean on a table with the unaffected arm. Gently dangle the sore arm so it is perpendicular to the floor. Swing your sore arm in small circles about the diameter of a dinner plate ten times both clockwise and counter clockwise. This gentle exercise takes pressure off of the rotator cuff while stretching the joint capsule. After starting exercises such as the shoulder pendulum the physical therapist will prescribe a series of rotator cuff strengthening exercises including therapy band work, scapular (shoulder blade) stabilizing exercises and stretches. The muscles surrounding the shoulder blade and rotator cuff will require exercises which will strengthen while not irritating the tissue.
Throughout your physical therapy program the therapist will discuss the proper ways to sit, stand and move while maintaining good posture. Instruction in the most efficient way to perform your job, sport or recreational activity is key to long term resolution of your condition.
Shoulder impingement is a common injury. If left untreated this injury can be debilitating and can lead to rotator cuff involvement and chronic pain. Physical therapy is a treatment is a non-invasive treatment which can help you to heal yourself.