Condition: Impingement syndrome of the shoulder (also called shoulder impingement syndrome [SIS]) is a clinical condition that occurs when the tendons of the rotator cuff muscles are squeezed as they pass through the shoulder.
Background: The causes of this condition include bone spurs and issues with the shoulder acromion bone. This type of impingement is termed “primary external impingement” and is the most common cause of shoulder pain, accounting for 40% of shoulder disorders. SIS can also be caused by inadequate stabilization of the shoulder blade, compression of the rotator cuff between the shoulder and top of the arm bone, injury, or repeated trauma to the rotator cuff muscles.
Risk Factors: SIS affects athletes and persons older than 40 years. A rising incidence in shoulder injuries in young athletes has been documented, likely due to the increase in year-round sports.
History and Symptoms: Patients describe pain on the front outside of the shoulder, especially with overhead activities such as throwing, painting or reaching a high shelf.
Physical Exam: A physical exam will be performed to evaluate pain, weakness, muscle symmetry, stability, and range of motion. The neck will be examined as well as the shoulder. Difficulties in daily activities, especially in the elderly, should be determined, and the biomechanics of common movements of athletes and workers should be evaluated. Clinical shoulder pain/disability tools are available to aid in diagnosis and treatment plans.
Diagnostic Process: X-rays and MRI may be used to evaluate the cause of the syndrome or pinpoint the injury. Ultrasound can also be used to obtain real-time information about the severity and cause of the shoulder condition.
Rehab Management: Current treatment guidelines involve rest, modification of activities, physical therapy to re-establish normal shoulder strength and range of motion, and pain medication. This rehabilitation is followed by training for coordination of muscles and integrating the entire movement into occupational and/or sport-specific training. If progress is stalled after several weeks, an injection of steroids into the shoulder may provide pain relief, allowing physical therapy. Surgery is necessary only in patients who do not improve within 3-6 months of treatment.
Other Resources for Patients and Families: Patients should be educated on SIS and the treatment options available. Patients, families, coaches, and employers should be made aware that recovery can be slow and that rushing back to participation (as in throwing athletes) can result in additional injuries.