Shoulder Impingement
Shoulder impingement syndrome is one of the most common causes of shoulder pain, especially in active individuals and those performing repetitive overhead movements. It occurs when the tendons of the rotator cuff or the bursa (a small fluid-filled sac that cushions the joint) become compressed or “impinged” as they pass through a narrow space beneath the acromion (part of the shoulder blade).
If left untreated, impingement can lead to inflammation, reduced range of motion, tendon degeneration, and potentially rotator cuff tears. With proper diagnosis and treatment—either nonoperative or surgical—most patients can recover well.
The shoulder is a complex ball-and-socket joint made up of the following structures:
Bones:
- Humerus: The upper arm bone.
- Scapula (shoulder blade): Includes the acromion, which forms the top of the shoulder.
- Clavicle (collarbone): Connects the shoulder to the sternum (breastbone).
Rotator Cuff:
- A group of four muscles and their tendons—supraspinatus, infraspinatus, subscapularis, and teres minor—that stabilize the shoulder and allow for lifting and rotating the arm.
Subacromial Space:
- The narrow space between the humeral head and the acromion. The supraspinatus tendon and the subacromial bursa pass through this space.
Bursa:
- A lubricating sac that reduces friction between the tendons and bones.
In shoulder impingement, the structures in the subacromial space become compressed, leading to irritation and inflammation.
The pain is typically located on the side or front of the shoulder and may radiate down the upper arm, but usually not past the elbow.
Common symptoms include:
- Pain during overhead activities such as lifting, throwing, swimming, or even reaching.
- Pain when lying on the affected shoulder, especially at night.
- Weakness or difficulty lifting the arm.
- Limited range of motion or stiffness in the shoulder.
- A painful catching, clicking, or popping sensation with movement.
Shoulder impingement is usually due to a combination of structural and functional issues.
Structural (Anatomical) Causes:
- Bone (acromial) spurs: Extra bone growth on the bottom acromion can reduce space in the subacromial area.
- Curved or hooked acromion: Some people naturally have an acromion shape that is curved or hooked downward that predisposes them to impingement.
- Thickening of ligaments or bursa: From chronic inflammation or aging.
Functional Causes:
- Muscle imbalance: Weakness or poor coordination in the shoulder blade or rotator cuff muscles.
- Repetitive overhead movements: Common in athletes (e.g., swimmers, pitchers) or workers (e.g., painters, construction workers).
- Poor posture: Forward-rounded shoulders or slouched upper back can contribute to narrowing the subacromial space.
- Rotator cuff overuse or degeneration: Especially in individuals over 40 years old.
Diagnosis is based on:
- Patient history and physical examination: The doctor will evaluate range of motion, strength, and specific shoulder tests (e.g., Neer or Hawkins test) that reproduce impingement symptoms.
- Imaging tests:
- X-rays: To assess bone spurs, acromion shape, or arthritis.
- MRI: To evaluate soft tissues like the rotator cuff tendons and bursa for inflammation or tears.
Most patients respond well to non-surgical treatments. Most people see significant improvement within 6–12 weeks with conservative management. These include:
Activity Modification
- Avoid or reduce overhead movements and heavy lifting.
- Use proper posture, especially at work or during sports.
Physical Therapy
- Stretching and strengthening exercises: Improve flexibility and restore balanced shoulder mechanics.
- Scapular stabilization: Strengthening the muscles around the shoulder blade can relieve pressure on the rotator cuff.
- Postural training: Helps prevent recurrence by improving body alignment.
Anti-inflammatory Medications
- NSAIDs (e.g., ibuprofen, naproxen) can reduce pain and inflammation.
Corticosteroid Injections
- A steroid injection into the subacromial space can relieve pain and inflammation, particularly if pain limits participation in therapy.
- Used judiciously—typically used 3-4 times per year depending on response and patient goals
Ice and Rest
- Applying ice after activities and taking brief periods of rest can help reduce acute inflammation.
Surgery may be considered if:
- Symptoms persist despite 3–6 months of nonoperative treatment.
- There is a rotator cuff tear that needs repair.
- Pain significantly affects sleep or daily activities.
The most common surgical procedure is:
Arthroscopic Subacromial Decompression
This is a minimally invasive procedure performed through small incisions using a camera (arthroscope). The goals are to:
- Remove inflamed bursa (bursectomy).
- Shave down bone spurs or flatten a hooked acromion (acromioplasty).
- Increase space in the subacromial area to relieve impingement.
If a rotator cuff tear is present, it may be repaired during the same procedure. Arthroscopic surgery is preferred due to faster recovery and less scarring.
Nonoperative Recovery:
- Up to 80% of patients improve with physical therapy, medication, and injections.
- Continued strengthening and postural correction reduce recurrence.
Post-Surgical Recovery:
- Outpatient procedure: Often performed same-day.
- Rehabilitation: Starts with passive range-of-motion exercises, progressing to strengthening over 8–12 weeks.
- Return to full activity: Usually by 3–6 months, depending on job or sport.
Most patients report significant pain relief and improved shoulder function after surgery. Success rates are high—around 85–90%—especially in patients without full-thickness rotator cuff tears.
- Warm up before activity.
- Strengthen shoulder and upper back muscles.
- Maintain flexibility.
- Practice good posture throughout the day.
- Avoid repetitive overhead activities when possible or take frequent breaks.
Contact a healthcare provider if you experience:
- Persistent shoulder pain not improving with rest or activity modification.
- Weakness or inability to raise the arm.
- Night pain affecting sleep.
- Shoulder stiffness that limits function.
Shoulder impingement syndrome is a treatable condition caused by narrowing of the space where tendons and soft tissues move in the shoulder. Early intervention with rest, therapy, and anti-inflammatories can often resolve symptoms. In more recurrent cases, surgical decompression offers a high chance of lasting relief. Prompt attention and a focus on rehabilitation are key to returning to an active, pain-free lifestyle.
At a Glance
Dr. Hasani Swindell
- Fellowship-Trained Sports Medicine Specialist
- Board-Certified Orthopedic Surgeon
- Summa Cum Laude Graduate from the University of Pittsburgh
- Medical Degree from Columbia University
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