Rotator cuff pain and shoulder impingement: why it happens and what helps
Published by the SMARTPHYSIO Clinical Team · Clinically reviewed · Published: 25 September 2026 · Last reviewed: 25 September 2026
Shoulder impingement, also called rotator cuff related shoulder pain, is irritation of the rotator cuff tendons as they pass through a narrow space under the tip of the shoulder blade, and it is one of the most common causes of shoulder pain seen in physiotherapy clinics. It typically causes a deep ache lifting the arm overhead or out to the side, and is not usually a sign of a serious tear.
It happens because the subacromial space the tendons run through gets narrower, or the tendons become less able to tolerate load, most often from a combination of age-related tendon changes, weak shoulder-blade control muscles, and a period of doing more overhead activity than the shoulder is used to. It is rarely one single cause.
If overhead movement, reaching behind your back, or lying on the affected shoulder at night is painful, and it has built gradually rather than starting with a specific injury, shoulder impingement is a reasonable working explanation. Most cases respond well to a structured exercise programme over six to twelve weeks, and only a small minority ever need surgery. If pain has lasted more than two to three weeks, or is disrupting sleep, a physiotherapy assessment is worth booking.
This guide covers why the shoulder gets irritated, a self-check for whether your pattern fits, what the evidence says about treatment, and the red flags that mean this is not straightforward impingement.
Why does the shoulder hurt with overhead movement?
Shoulder impingement happens because the rotator cuff tendons are compressed in a narrow space under the shoulder blade, and that space narrows further when the muscles controlling the shoulder blade are not working well.
The rotator cuff is a group of four muscles and tendons that hold the ball of the shoulder joint centred in its socket and help lift and rotate the arm. These tendons pass through the subacromial space, a gap between the arm bone and the shoulder blade above it, which naturally narrows as you lift your arm sideways or overhead. In a healthy shoulder, the muscles around the shoulder blade fine-tune its position to keep enough room for the tendons to glide through. When those control muscles are weak, the tendons get pinched with every overhead movement, which is why pain is so consistently linked to a specific arc of motion rather than being constant.
This is also why rest alone rarely fixes it: it does nothing to rebuild the shoulder blade control or tendon capacity that let the pinching happen, so pain tends to return once normal activity resumes. Internal factors (tendon ageing, the shape of the bony arch) combine with external factors (posture, a sudden jump in overhead activity) to determine how much load a shoulder can tolerate.
Is this shoulder impingement? A quick self-check
Shoulder impingement typically causes pain with overhead reaching that improves once the arm is lowered past the painful arc, without the dramatic weakness of a major tear or the near-total stiffness of frozen shoulder.
Pattern you notice | What it suggests |
|---|---|
Pain in a specific arc when lifting the arm sideways or overhead (roughly 60 to 120 degrees), easing above and below that arc | Typical of shoulder impingement |
Pain lying on the affected side at night, disturbing sleep | Common in impingement, also common in rotator cuff tendinopathy generally |
Sudden inability to lift the arm away from the body after a specific injury, or the arm "gives way" | Suggests a possible larger rotator cuff tear, worth an earlier assessment |
Gradual, worsening stiffness in all directions over weeks to months, with movement blocked even when someone else tries to move it for you | Suggests frozen shoulder rather than impingement, a different condition and treatment path |
Pain that started with no clear trigger and has been present, unchanged, for several months without ever really settling | Worth an assessment to rule out other causes, including referred pain from the neck |
If your pattern matches the first two rows, shoulder impingement is a reasonable working diagnosis and worth starting on an exercise-led plan. If it matches the third or fourth row, book an assessment rather than starting a generic exercise sheet, since the right early treatment differs.
What the evidence actually says about treatment
A 2026 systematic review in BMC Musculoskeletal Disorders, pooling 21 RCTs and 1,152 participants, found exercise-based treatment meaningfully reduces pain and improves function and range of movement, though gains in raw strength were smaller and not statistically significant. Exercise reliably helps you move and hurt less, but a visible strength jump is not guaranteed, and function usually improves before strength catches up.
NHS Lanarkshire's guidance sets a similarly realistic timeline: graduated exercise through early, middle and late stages, a minimum of six to eight weeks before meaningful improvement, and surgery reserved for roughly 5% of cases. Versus Arthritis makes the same point from the patient side: both tears and impingement generally respond well to physiotherapy, and modified activity alongside exercise, rather than full rest, tends to work best.
The evidence is more mixed on which specific exercises matter most; the 2026 review noted very high variability between pooled trials, so "an exercise programme, done consistently" is better-supported than any single exercise being proven superior, which is why a generic sheet often underperforms a plan built around your specific weakness. CSP-reviewed research on rotator cuff-related shoulder pain found resisted, progressive exercise outperforms non-resisted, non-progressive versions of the same programme, which is one reason the specifics of how an exercise plan is loaded and progressed matter.
Sleeping and daily-life changes that help
Sleeping propped up or on your back with the affected arm supported on a pillow, rather than on the sore side, is the single change that most reliably settles night pain from shoulder impingement.
Side-lying on the affected shoulder compresses the same narrowed space that overhead movement irritates, which is why night pain is so common and often the symptom that finally prompts people to book an assessment. Sleeping on your back with a small pillow supporting the arm, or on the unaffected side with the sore arm resting on a pillow in front of you, takes that compression off. During the day, avoid prolonged overhead reaching while symptoms are acute, and be mindful of carrying heavy bags on the affected shoulder.
When is this not straightforward impingement?
Seek same-day medical assessment, rather than booking routine physiotherapy, if shoulder pain follows a significant injury with sudden severe weakness, or if it comes with fever, redness, or bilateral shoulder and hip-girdle pain and stiffness in someone over 50.
Most shoulder impingement is safe to manage with physiotherapy, but a few patterns need medical review:
A shoulder that suddenly cannot be lifted away from the body after a fall or direct blow, particularly with visible bruising or deformity, which needs same-day assessment to rule out a tear, dislocation, or fracture.
Shoulder pain with fever, redness, warmth, or feeling generally unwell, which needs same-day GP or 111 assessment to rule out joint infection.
Severe pain in both shoulders and hips, with morning stiffness lasting over 45 minutes, in someone over 50, which can signal polymyalgia rheumatica and needs a GP assessment.
Numbness or weakness spreading down the whole arm, or neck pain that came first, which points towards the neck as the source and changes the plan.
Chest pain, breathlessness, sweating, or pain spreading to the jaw or left arm, which needs a 999 call, since cardiac pain can present through the shoulder.
How we assess and treat it at our London clinics
A shoulder assessment with our physiotherapy team in London typically runs a full hour, ruling out the red flags above before testing the movements that distinguish impingement from a tear, frozen shoulder, or neck referral. From there we build a staged loading programme, starting with pain-controlled isometric holds before progressing through resistance band and free-weight work, adjusting the pace to your job or sport around our Soho clinic near Carnaby Street and Regent Street. For shoulders not responding to loading alone, shockwave therapy at our clinic can be discussed as a second-line option.
Common questions
How long does shoulder impingement take to heal?
Most people see meaningful improvement within six to eight weeks of a consistent exercise programme, with fuller recovery over three to six months for established cases. Progress is usually steady, and stopping exercises once pain first eases is the most common reason it returns.
Can I still exercise with shoulder impingement?
Generally yes, with the overhead range and load adjusted to stay below a level that provokes sharp pain. Complete rest is not usually the right approach, since the shoulder blade control and tendon capacity that need rebuilding only improve with graded loading, not with avoidance.
Is shoulder impingement the same as a rotator cuff tear?
No, though the two overlap and can occur together. Impingement describes the tendons being compressed and irritated; a tear is an actual structural break in the tendon, which is more likely after a specific injury or with sudden, significant weakness. Both usually start with physiotherapy, but the assessment and expected timeline differ.
Do I need a scan for shoulder impingement?
Not usually as a first step. Most impingement is diagnosed from your history and a physical examination, and a scan is reserved for cases that do not improve with a proper course of physiotherapy, or where a significant tear or another structural cause is suspected from the assessment.
Why is my shoulder worse at night than during the day?
Lying on the affected side compresses the same narrowed subacromial space that overhead movement irritates during the day, and there is less distraction from other activity at night, which makes the discomfort more noticeable. Changing your sleep position, as described above, is usually the quickest way to improve this specific symptom.
Will I need surgery for shoulder impingement?
Most people do not. NHS guidance and the wider evidence both indicate that only a small proportion, roughly one in twenty, of people who complete a proper course of exercise-based physiotherapy go on to need surgery, so a structured non-surgical programme is the appropriate starting point for almost everyone.
About the author
This article was written and clinically reviewed by the SMARTPHYSIO Clinical Team, a group of HCPC-registered physiotherapists working across three central London clinics and on home visits London-wide. The team regularly assesses and treats shoulder impingement and rotator cuff related shoulder pain, building staged loading programmes around each patient's specific job, sport, and daily demands. Read more about the team at SMARTPHYSIO.
Book a clinic appointment
If overhead movement or a bad night's sleep keeps coming back to your shoulder, an assessment can confirm what is going on and get a proper loading plan started. Book a clinic appointment at Highgate, Hampstead or Soho, and let our team build a programme around your shoulder.
