Shoulder impingement syndrome, also called thrower’s shoulder, is a condition in which rotator cuff tendons are compressed as the shoulder moves.
The tendons rub against the bone at the top of the shoulder, called the acromion. This causes swelling and tenderness, and pain may radiate from the shoulder down the arm, particularly when the arm is lifted or when reaching up behind the back.
Left untreated, pain can worsen and patients can develop a loss in strength and a decreased range of motion. This syndrome often develops in people who repeatedly use or overuse their shoulder muscles, such as pitchers, tennis players and painters.
Causes of Shoulder Impingement
Rotator cuff muscles and tendons are surrounded by bone. Only a small space, called the subacromial space, allows the tendons to pass through the joint.
Conditions that cause narrowing of this space are what lead to shoulder impingement. Bone spurs or overgrowths under the acromion, loss of thoracic mobility, or dysfunctional scapular movement can cause the tendon or bursa to become trapped during movement. The fluid-filled sac (called the bursa) that provides a smooth gliding surface for the tendons may become inflamed, which causes a painful condition known as bursitis, which can lead to further impingement.
The rotator cuff tendons also may become swollen or thickened due to an injury or overuse, leading to calcium deposit buildup or tendon fiber disorganization (tendinopathy).
Shoulder Impingement Diagnosis
This syndrome is initially diagnosed through a medical history and physical examination.
During the initial exam, the doctor may move your arm into various positions, twisting and lifting to determine the range of motion and the extent of pain. The doctor may also inject a small amount of anesthetic into the bursa; if this provides a decrease in pain and an improvement in the range of motion, the patient likely has impingement.
X-rays may be ordered to rule out arthritis and bone injuries. An MRI also may be ordered to provide a better view of the tendons and muscles.
With special training, your physician may be able to use diagnostic ultrasound to evaluate your rotator cuff tendons and bursa. This unique technology is a low-cost, radiation-free option that may provide a quicker diagnosis.
Treatments for Shoulder Impingement
Patients are advised to rest the shoulder and avoid painful activities.
For persistent symptoms that do not respond to activity modification, your doctor may recommend physical therapy. A specialist such as Dr. Engelen can provide an individualized therapy regimen that typically focuses on thoracic spine mobility, scapular stabilization, neuromuscular re-education, and rotator cuff strengthening.
Therapy may be aided by corticosteroid injections for pain relief. If tendinopathy is suspected, PRP (platelet-rich plasma) treatment may be indicated.
Rarely, arthroscopic or open surgery may be advised to widen the subacromial space, if your injury fails to respond to non-operative treatment.
If you have developed pain, tenderness or decreased motion in your shoulder, contact our office for an evaluation. Left untreated, shoulder impingement can result in chronic pain and loss of function.