Diagnosis

Shoulder impingement syndrome

Also known as: Subacromial impingement syndrome, Rotator cuff impingement

Overview

Shoulder impingement syndrome is a common cause of shoulder pain where the tendons of the rotator cuff and the bursa can become irritated as they pass through the space under the acromion (the "roof" of the shoulder). This irritation often flares with lifting the arm, reaching overhead, or certain shoulder positions. The condition can lead to pain-limited movement, weakness, and nighttime discomfort. It is usually treatable without surgery, especially when addressed early with activity changes and targeted therapy.

Symptoms

Pain is usually felt at the front or side of the shoulder and may spread to the upper arm, especially when reaching overhead or behind the back. Many people notice pain when lowering the arm from an elevated position, and some develop aching that worsens at night. As symptoms persist, the shoulder may feel stiff and strength can drop because using the shoulder hurts. Some patients also report a catching or grinding sensation during movement.

Causes

Shoulder impingement commonly develops from tendon and bursa overload, where repetitive overhead activity or poor shoulder mechanics narrow the functional space under the acromion. Inflammation and thickening of the bursa or tendons can increase friction during arm elevation. Bone shape differences, age-related tendon degeneration, and decreased shoulder flexibility or strength can all contribute to the impingement pattern.

Risk Factors

Risk is higher in people who work or train with frequent overhead motions, such as painting, lifting, swimming, tennis, and throwing sports. Limited shoulder mobility, weak rotator cuff and scapular stabilizer muscles, and poor posture can increase mechanical stress. Age-related tendon wear and prior shoulder injuries or chronic inflammation can make symptoms more likely. Smoking and overall deconditioning can also slow recovery from tendon irritation.

Prevention

You can reduce recurrence by avoiding long periods of repetitive overhead reaching during flare-ups and gradually rebuilding activity tolerance. Strengthening the rotator cuff and the muscles that control the shoulder blade, along with improving shoulder range of motion, helps keep the arm moving smoothly. Using better lifting and throwing mechanics and keeping the shoulder relaxed during daily activities can reduce tendon overload. Maintaining general fitness and avoiding smoking can support tendon health.

How the Diagnosis Is Evaluated

Clinicians usually start with a history focused on how the pain began, what movements trigger it, and whether there was a specific injury. A physical exam typically checks range of motion, strength, shoulder blade motion, and pain patterns using maneuvers such as the Neer and Hawkins-Kennedy tests, while also evaluating the neck and nerves. Imaging is not always necessary, but X-rays may be used to look for bone spurs or arthritis. Ultrasound or MRI may be ordered if symptoms are severe, persist despite treatment, or if a rotator cuff tear or other condition is suspected.

Nonsurgical Treatment Options

Treatment typically begins with activity modification to calm irritation, along with pain control using heat or ice and short-term anti-inflammatory medications if appropriate for you. Physical therapy is often the cornerstone and focuses on restoring shoulder mechanics by improving mobility and strengthening the rotator cuff and scapular stabilizers. Corticosteroid injection into the subacromial space can reduce inflammation and pain when symptoms do not improve enough with therapy. Platelet-rich plasma (PRP) injections may be considered in some cases of persistent tendon irritation, though results vary and availability differs. Trigger point injections can help if muscle spasm contributes to pain, and in selected situations where joint irritation coexists with arthritis, hyaluronic acid injections may be discussed. Other biologic options such as adipose allograft or stem cell injections are usually reserved for carefully selected, refractory cases and are often considered investigational or off-label.

When to Seek Medical Attention

Seek prompt medical attention if you had a significant injury, notice sudden loss of shoulder function, or cannot lift the arm after a fall or trauma. Get urgent care for fever, increasing redness or swelling, or severe unrelenting pain that does not allow you to sleep. Contact a clinician soon if weakness is worsening, symptoms persist beyond a few weeks despite conservative care, or you develop numbness or tingling that spreads down the arm. If shoulder pain is accompanied by chest pressure, shortness of breath, or other signs that suggest a non-musculoskeletal cause, seek emergency evaluation.

Frequently Asked Questions

It typically causes pain at the front or side of the shoulder that worsens with overhead reaching and may disturb sleep at night.

Yes, for most people physical therapy improves pain and function by correcting shoulder mechanics and strengthening key muscles.

Next Steps

If your shoulder pain is triggered by overhead movement or is limiting daily activities, consider booking an evaluation with a clinician experienced in shoulder problems. In the meantime, modify activities to avoid painful ranges and start gentle, symptom-guided mobility while planning targeted strengthening through physical therapy. If you develop significant weakness after an injury or any red-flag symptoms, seek prompt medical care.

JP
Medically reviewed by Jason Pirozzolo, DO Medical Director · Last reviewed May 2026
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