Shoulder Impingement

What Is Shoulder Impingement?

Shoulder impingement (subacromial pain syndrome) occurs when the tendons of the rotator cuff become irritated and inflamed as they pass through the subacromial space—the gap between the top of the arm bone and the acromion. It's one of the most common causes of shoulder pain.¹

Symptoms²

Pain with overhead activities
Pain when reaching behind back
Pain at night, especially lying on shoulder
Pain lifting arm to the side
Weakness in shoulder
Painful arc (pain in mid-range of motion)

Causes and Risk Factors

Repetitive overhead activities
Swimming, tennis, baseball
Painting, construction work
Poor posture
Muscle imbalances
Aging changes
Bone spurs

Diagnosis³

Physical examination
Specific impingement tests
X-rays may show bone changes
MRI if rotator cuff tear suspected
Ultrasound sometimes helpful

Treatment

Conservative (First-Line)

Rest from aggravating activities
Physical therapy (cornerstone)
NSAIDs
Ice
Posture correction

Injections

Corticosteroid injection
Can reduce inflammation
May allow better PT participation

Surgery

Subacromial decompression
Usually only if conservative fails
Arthroscopic procedure

Physical Therapy Focus

Rotator cuff strengthening
Scapular stabilization exercises
Posture training
Flexibility work
Movement pattern correction

Self-Care

Avoid painful overhead reaching
Sleep on opposite side
Good posture (avoid forward head)
Regular rotator cuff exercises
Modify aggravating activities

Prognosis

Most improve with conservative care
May take 6-12 weeks
Consistent exercise important
Address underlying causes to prevent recurrence

References

Diercks R, Bron C, Dorrestijn O, et al. Guideline for diagnosis and treatment of subacromial pain syndrome. Acta Orthop. 2014;85(3):314-322.
Neer CS II. Impingement lesions. Clin Orthop Relat Res. 1983;(173):70-77.
Michener LA, McClure PW, Karduna AR. Anatomical and biomechanical mechanisms of subacromial impingement syndrome. Clin Biomech. 2003;18(5):369-379.