Shoulder impingement happens when the tendons of the rotator cuff and the fluid-filled cushion (bursa) above them get pinched in the narrow space between your upper arm bone and the bony roof of your shoulder. The good news: most cases resolve with targeted exercises, habit changes, and time. Recovery typically takes 6 to 8 weeks before you notice real improvement, though severe cases can stretch to 6 months or even a year.
What’s Actually Getting Pinched
The subacromial space is a small gap between the top of your arm bone and the bony arch above it. Packed into that gap are the supraspinatus tendon (the most commonly irritated rotator cuff tendon), the subacromial bursa, and the tendon of the long head of your biceps. When these structures swell from overuse or get repeatedly compressed from poor mechanics, every time you raise your arm the inflamed tissue gets squeezed further. That creates a cycle: compression causes swelling, swelling narrows the space, and the narrower space causes more compression.
Why It Happens
Impingement is rarely about one single cause. It usually results from a combination of factors working together: weak or imbalanced rotator cuff muscles that fail to pull the arm bone down and away from the bony arch during overhead movements, tight chest muscles that round the shoulders forward, and a stiff upper back. A rounded upper back (thoracic kyphosis) restricts overhead range of motion and forces the shoulder joint to compensate, which alters how the shoulder blade moves and directly contributes to impingement. Repetitive overhead activities, from painting a ceiling to swimming to pressing a barbell, accelerate the problem.
Strengthening the Rotator Cuff
Targeted strengthening is the single most effective fix. A large trial published in the British Journal of Sports Medicine found that working with a physiotherapist produced significantly better outcomes at 6 months compared to following a basic exercise leaflet alone. The difference disappeared by 12 months, but only because adherence dropped off. The takeaway: consistency matters as much as the exercises themselves.
The UCSF Orthopaedic Institute recommends a structured progression. In the early phase, start with isometric exercises (pushing against resistance without actually moving the joint) to build baseline strength without irritating the tendon. Hold each contraction for 5 seconds, repeat 10 times, and do one set three times a day. These include pressing your fist gently into a wall in front of you, behind you, and to each side.
Once isometric work feels comfortable, progress to resistance band exercises:
- External rotation: Elbow pinned to your side, rotate your forearm outward against a band. 12 to 15 reps, hold each for 3 seconds, one set three times daily.
- Internal rotation: Same setup, rotating inward. Same volume.
- Open can exercise: Raise your arm about 30 degrees out from your body with your thumb pointing up, like pouring from a can. This targets the supraspinatus directly. 12 to 15 reps, three times daily.
- Horizontal rows: Pull a band toward your torso with your elbow close to your side. 12 to 15 reps, three times daily.
- Shoulder extension: Pull a band backward behind your hip. 12 to 15 reps, three times daily.
Perform strengthening on alternating days to allow recovery. When the exercises feel easy, increase repetitions until you reach muscle fatigue rather than jumping to heavier resistance.
Fixing the Shoulder Blade
The rotator cuff doesn’t work in isolation. Your shoulder blade needs to rotate smoothly as you lift your arm, and if the muscles controlling it are weak, the subacromial space narrows at the worst possible moment. Two exercises address this directly:
- Scapular retraction (blade squeezes): Squeeze your shoulder blades together, hold for 10 seconds, then relax. Repeat 10 times, one set three times a day.
- Scapular elevation (shrugs with a hold): Shrug your shoulders up, keep your core engaged, hold for 10 seconds. Repeat 10 times, one set three times a day.
These look simple, but they train the stabilizers that keep the shoulder blade anchored in the right position during larger movements.
Improving Upper Back Mobility
A stiff, rounded thoracic spine limits how far you can reach overhead and forces the shoulder to pick up the slack. Foam rolling your upper back for a few minutes daily and performing thoracic extension stretches (draping backward over a rolled towel or foam roller placed at mid-back level) can restore the mobility your shoulder needs. Cat-cow stretches and thread-the-needle rotations help as well. This is one of the most overlooked pieces of impingement rehab, but addressing it often produces a noticeable reduction in pinching within weeks.
Sleep and Daily Habits
Sleep position can make or break your recovery. Sleeping face down with your arm tucked under the pillow compresses the shoulder in a worst-case position, essentially recreating impingement for hours at a time. If you sleep on your back, rest your affected arm on a folded blanket or low pillow so the shoulder stays aligned with your body and doesn’t sag into the mattress. Side sleepers should keep the affected shoulder on top and support that arm on a pillow to hold it in a neutral, straight position.
During the day, avoid sustained overhead reaching and repetitive movements that reproduce your pain. This doesn’t mean total rest. Gentle movement and the exercises described above are better than immobilization. But continuing to push through sharp, pinching pain during activities will keep the cycle going.
Do Cortisone Injections Help?
A single corticosteroid injection can provide short-term relief of both pain and function, which the 2025 AAOS clinical practice guidelines acknowledge as a reasonable option. However, the same British Journal of Sports Medicine trial found no meaningful difference in outcomes between guided and unguided injections at any time point (6 weeks, 6 months, or 12 months). And injections didn’t change long-term outcomes compared to exercise alone. About 45 out of 148 participants in the trial ended up getting repeat injections over 12 months regardless of their initial treatment group.
Injections are best thought of as a pain-management bridge. They can reduce inflammation enough to let you do your rehab exercises, but they don’t fix the underlying mechanical problem.
When Surgery Comes Into Play
Surgery for impingement (subacromial decompression, where a surgeon shaves bone to widen the space) is typically reserved for people who have completed several months of rehab without meaningful improvement. The evidence for it is surprisingly underwhelming. A Cochrane review found that 71 out of 100 people rated their outcome as successful after surgery, but 66 out of 100 said the same after a placebo procedure where no bone was actually removed. That narrow gap suggests much of the surgical benefit may come from the rehab process that follows rather than the procedure itself.
For people with full-thickness rotator cuff tears (a more advanced injury that impingement can progress to), both physical therapy and surgery produce significant improvement in reported outcomes according to the 2025 AAOS guidelines. But patients choosing non-operative management should know that tear size, muscle wasting, and fatty changes in the muscle can progress over 5 to 10 years without repair.
Realistic Recovery Timeline
Most people start feeling noticeably better at the 6 to 8 week mark with consistent rehab. Milder cases can resolve in a few weeks. More severe or longstanding cases, especially those involving significant tendon damage, may take 6 months to a year. The biggest predictor of recovery speed is exercise adherence. In the British Journal of Sports Medicine trial, 86% of participants working with a physiotherapist were still doing their exercises daily at 6 weeks, but that dropped to 49% by 12 months, and outcomes declined along with it.
The most common mistake is stopping rehab once the pain fades. The structural imbalances that caused impingement don’t resolve in a few weeks. Maintaining rotator cuff and scapular strengthening exercises two to three times per week, even after symptoms resolve, is the most reliable way to prevent recurrence. Returning to overhead activities too early, before strength is fully restored, significantly increases the risk of reinjury or progression to a rotator cuff tear.