Muscle, joint & pain

Impingement or a Torn Cuff

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Pain that flares when reaching overhead has two very different possible sources: irritated tendons pinching in a tight space, or an actual tear in the rotator cuff itself. The two overlap enough in how they feel that people often can't tell them apart on their own. This guide covers what separates them on exam, what imaging adds, and what the surgical evidence actually shows for each, since the two conditions do not carry the same odds of needing an operation.

Last updated: July 2026

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What Is Shoulder Impingement, and What Does It Feel Like?

Shoulder impingement describes pain from the rotator cuff tendons and the bursa above them getting pinched in the narrow space beneath the tip of the shoulder blade, most often during a mid-range arc of lifting the arm overhead. The tendon itself is usually irritated or inflamed rather than torn, and strength is typically preserved even though the motion hurts 1.

The pain pattern is fairly distinctive: reaching to a shelf, tucking in a shirt behind the back, or lifting the arm through roughly the middle third of overhead motion reproduces it, while the arm often moves painlessly below and above that arc. It tends to build gradually, frequently tied to repetitive overhead activity at work or in sport, rather than appearing suddenly after one specific event.

Torn Cuff or Just Tendinitis? What a True Tear Feels Like

A rotator cuff tear is a structural break in one or more of the tendons that stabilize and move the shoulder, and it announces itself differently from tendinitis: real weakness lifting or rotating the arm, sometimes a genuine inability to raise it away from the body at all, and pain that frequently disturbs sleep when lying on that side. Rotator cuff tears are a common cause of shoulder pain, responsible for nearly two million clinic visits a year in the United States 2.

Tears come in two broad flavors that matter for what happens next, and the split between partial versus full-thickness rotator cuff tears matters just as much as which flavor a given tear is. A traumatic tear follows a specific event, a fall onto an outstretched arm, a heavy sudden pull, a shoulder dislocation, and tends to appear in younger, more active people. A degenerative tear develops gradually from years of wear, is far more common with age, and often exists for a long time, sometimes as a partial tear with a slow cuff tear progression, before it causes enough weakness or pain to be noticed 2.

How the Two Are Told Apart on Exam

The most useful distinguishing feature is strength: impingement causes pain with motion but the arm still moves against resistance, while a meaningful cuff tear causes measurable weakness, and a large tear can produce a positive drop arm test, an inability to hold the arm up once it is raised passively to shoulder height. Pinpointing exactly when the pain and weakness began, gradually or after one specific event, also carries real diagnostic weight, and is often the first fork in the rotator cuff repair decision.

Imaging is not always needed to start treatment, but ultrasound or MRI becomes useful when strength testing is equivocal, when a tear needs to be sized before deciding on surgery, or when symptoms haven't improved after a genuine trial of conservative care. Frozen shoulder or a torn cuff can also be hard to tell apart at first, since both limit overhead reach, but frozen shoulder restricts motion in every direction, including when someone else moves the arm for you, rather than just through an overhead arc; working out that shoulder stiffness differential is part of the same exam that separates impingement from a tear.

What the Evidence Shows About Surgery for Impingement

For shoulder pain from impingement and bursitis without a structural tear, the operation historically offered, subacromial decompression, which shaves away bone and tissue to widen the space the tendons pass through, has been tested directly against a placebo procedure and against no treatment at all. Neither comparison favored the surgery: a large placebo-controlled trial found no clinically important benefit over sham surgery or no treatment for subacromial shoulder pain 3, and a Cochrane review of the same question, drawing on high-certainty evidence, reached the same conclusion 4.

That finding reshaped how impingement is approached: physical therapy focused on strengthening the muscles around the shoulder blade and rotator cuff, along with activity modification and, for some, an injection to calm inflammation, is the reasonable starting point for nearly everyone with impingement-type pain, and it is what the evidence actually supports rather than surgery being held in reserve as a formality.

What the Evidence Shows About Surgery for Degenerative Cuff Tears

For tears that develop gradually rather than from a specific injury, the evidence points in a similar direction. A randomized trial, often referred to as the Kukkonen trial, compared physical therapy alone, decompression surgery plus therapy, and cuff repair plus therapy, and found no significant difference between the three groups at two years for nontraumatic supraspinatus tears, making a structured conservative program a reasonable place to start 5. A broader Cochrane review of surgical repair for rotator cuff tears reached a similarly cautious conclusion: repair probably provides little or no clinically important benefit over non-operative, exercise-based treatment for pain and function in many cases 6.

For many degenerative tears, starting with a structured physical therapy program is a reasonable, evidence-supported choice, not a delay tactic. That does not mean surgery is the wrong choice for a given tear; it means the decision should rest on the specific tear and the specific person, not on the assumption that a visible tear on a scan automatically requires fixing.

When Surgery for a Rotator Cuff Tear Is Clearly the Right Call

None of this evidence argues against surgery in general; it argues for matching the operation to the tear. Surgery earns a clear place in several specific situations: an acute, traumatic full-thickness tear, especially in a younger or physically active person who needs full overhead strength for work or sport, since these tears do not reliably heal or regain strength on their own. A tear causing significant, measurable weakness that limits daily function, rather than pain alone, also weighs toward repair. So does a tear that is enlarging on follow-up imaging, or one that has genuinely failed a structured physical therapy program of several months without meaningful improvement.

The frame that fits the evidence best is a sequence of care rather than a choice between surgery and nothing: for most impingement and many degenerative tears, physical therapy is the reasonable first step, with surgery reserved for the tears and the people it is most likely to help. Getting the type of tear right, partial versus full-thickness, traumatic versus degenerative, changes which end of that sequence makes sense to start on.

Common questions

It can, particularly with continued repetitive overhead strain on already-irritated tendons, though not every case of impingement progresses to a tear. This is one reason persistent overhead shoulder pain is worth having examined rather than pushed through indefinitely, even though the initial treatment for both conditions often overlaps.

No. Many degenerative tears, especially smaller ones without major weakness, do about as well with a structured physical therapy program as with surgery, based on randomized trial evidence. Surgery is favored for acute traumatic tears in active people, tears causing significant weakness, or tears that have not responded to a genuine course of conservative treatment.

It's a simple exam maneuver: the examiner raises the arm out to the side and lets go, and someone with a significant rotator cuff tear cannot hold it up, so it drops. It's a useful sign of a larger tear, though a normal result doesn't rule out a smaller one, and it's typically combined with other strength tests.

Not always at first. A clinician can often distinguish the two from the story and a strength-focused exam, and many people start physical therapy without imaging. An MRI or ultrasound becomes more useful when strength testing is unclear, when surgery is being considered, or when a genuine trial of conservative treatment hasn't helped.

Trial evidence has found that subacromial decompression, the operation traditionally used for impingement, performs no better than a placebo procedure or no treatment at all for many people. That doesn't mean the surgery never helps anyone, but it explains why physical therapy is now favored as the starting point for impingement-type pain rather than surgery.

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When Shoulder Pain Needs Prompt Evaluation

  • —Sudden inability to lift the arm after a fall, a forceful pull, or a dislocation
  • —A shoulder that is hot, red, and swollen along with fever, which can signal joint infection
  • —Numbness or weakness spreading down the arm rather than staying at the shoulder
  • —Shoulder pain with chest pressure, shortness of breath, or sweating

Shoulder pain that comes with chest pressure, shortness of breath, or sweating warrants calling 911 rather than waiting for a routine appointment, since it can signal a heart problem rather than a shoulder one.

This guide is general health education, not medical advice, and cannot diagnose the cause of your shoulder pain. A clinician who can examine and test the strength of the shoulder should guide evaluation and treatment.

References

  1. 1.American Academy of Orthopaedic Surgeons (OrthoInfo) (2024). Shoulder Impingement / Rotator Cuff Tendinitis. OrthoInfo — AAOS. link ✓Describes shoulder impingement / rotator cuff tendinitis and bursitis, including causes and symptoms, used to characterize the impingement pain pattern.
  2. 2.American Academy of Orthopaedic Surgeons (OrthoInfo) (2024). Rotator Cuff Tears. OrthoInfo — AAOS. link ✓Rotator cuff tears are a common cause of shoulder pain accounting for nearly two million US visits per year, used to describe the frequency and traumatic-versus-degenerative distinction of tears.
  3. 3.Beard DJ, Rees JL, Cook JA, et al. (CSAW) (2018). Arthroscopic subacromial decompression for subacromial shoulder pain (CSAW): a multicentre, pragmatic, parallel group, placebo-controlled, three-group, randomised surgical trial. The Lancet. doi:10.1016/S0140-6736(17)32457-1Arthroscopic subacromial decompression provided no clinically important benefit over placebo or no treatment for subacromial shoulder pain, used to describe the evidence on decompression surgery for impingement.
  4. 4.Karjalainen TV, Jain NB, Page CM, et al. (2019). Subacromial decompression surgery for rotator cuff disease. Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD005619.pub3 ✓High-certainty evidence that subacromial decompression does not provide clinically important benefits over placebo or non-surgical care, used alongside the CSAW trial to describe the surgical evidence for impingement.
  5. 5.Kukkonen J, Joukainen A, Lehtinen J, et al. (2015). Treatment of Nontraumatic Rotator Cuff Tears: A Randomized Controlled Trial with Two Years of Clinical and Imaging Follow-up. Journal of Bone and Joint Surgery (American). doi:10.2106/JBJS.N.01051 ✓Physiotherapy alone, decompression plus physiotherapy, and cuff repair plus physiotherapy produced no significant clinical difference at two years for nontraumatic tears, used to support conservative care as a reasonable first step for degenerative tears.
  6. 6.Karjalainen TV, Jain NB, Heikkinen J, et al. (2019). Surgery for rotator cuff tears. Cochrane Database of Systematic Reviews. doi:10.1002/14651858.CD013502 ✓Rotator cuff repair probably provides little or no clinically important benefit over non-operative exercise-based treatment for many tears, used to summarize the broader surgical-repair evidence.

6 sources, numbered by first appearance. General health information, not medical advice. AI-assisted editorial content — citations link their sources. Editorial policy

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