Swimmer's shoulder is the name given to shoulder pain that appears in people who swim regularly. It is a convenient label, but it needs to be said straight away: it is not a precise diagnosis. Very different situations end up under the same name, and research over recent years has scaled back many of the explanations you read everywhere. In this guide you will find what is really documented, what is only plausible and what you can do with what we know.
If you are looking for a promise of recovery from swimmer's shoulder, this article will disappoint you. If instead you want to understand why your shoulder hurts and how to manage swimming and loads without fooling yourself, you are in the right place.
⚠ Important: read this before continuing
The exercises and advice in this article are general indications and may not suit your situation. Every person has a unique clinical history: what works for others could be counterproductive for you.
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First of all: when shoulder pain is not "swimming pain"
This part should be read first, not at the end. Shoulder pain in swimmers is almost always a load problem, but not always. There are situations in which a quick medical assessment is needed, not an exercise programme:
- Pain that appeared after a clear trauma, a fall, a knock or a violent movement in which you felt a tear or a snap.
- You cannot raise your arm or your strength has suddenly collapsed, especially after an acute painful episode.
- The shoulder has come out of place or you feel it slipping away during certain movements.
- Tingling, numbness or loss of strength running down the arm to the hand: it may be the neck, not the shoulder.
- Night pain that does not ease in any position, that wakes you every night and has nothing to do with movement.
- Fever, a hot, red and swollen area, general malaise: an inflammatory or infectious picture needs to be ruled out.
- Pain that appears at rest, unrelated to moving the arm, perhaps with breathlessness or a feeling of pressure: pain referred from an internal organ or the heart can be felt in the left shoulder.
- Unexplained weight loss, a previous history of cancer, pain that gets progressively worse and does not respond to anything.
If you recognise yourself in any of these points, the priority is a clinical assessment, not training dry. We have written a dedicated guide on shoulder pain and when to worry to help you distinguish the various origins.
How common it really is
On how frequent swimmer's shoulder is, the figure that circulates everywhere is "90% of swimmers". It is true only in part, and it is useful to understand where it comes from.
A systematic review published in the Journal of Athletic Training in 2020 gathered 12 studies covering a total of 1,460 competitive swimmers, divided by age group. 91.3% concern adolescents aged 15 to 17, the most exposed group of all. If this is the case for your child, the picture seen from a parent's side is in the young swimmer's shoulder. In the other age groups the prevalence of shoulder pain varies across a very wide range, from 19.4% to 70.3%. Quoting "90%" as if it applied to anyone who swims means taking the highest value from an enormous range and passing it off as the norm.
The practical message is this: shoulder pain in swimming is common and seems to grow with years of practice, peaking in adolescence. But it is not a sentence, and it does not affect nine swimmers out of ten.
The uncomfortable chapter: impingement alone does not explain the pain
The classic explanation of swimmer's shoulder says that in the pull phase the space under the acromion narrows, the tendons get compressed and everything starts from there. It is a mechanically elegant story. The problem is that, when you look closely, that compression is found in almost everyone.
In 2016 a study of the 2008 US Olympic swimming team was published in the American Journal of Sports Medicine: the athletes were assessed with clinical examination and dynamic ultrasound. 66% of the athletes, 29 out of 42, reported a history of shoulder pain. Structural changes were very widespread: changes compatible with tendinosis of the supraspinatus or infraspinatus in 44 shoulders out of 46 (96%), of the long head of the biceps in 33 out of 46 (72%). Subacromial impingement was seen on dynamic ultrasound in 34 shoulders out of 41 (83%), subcoracoid impingement in 17 out of 46 (37%).
Before drawing conclusions, a warning about the denominators: the 66% is calculated on the athletes (29 out of 42), while the ultrasound percentages are calculated on the shoulders examined (46, or 41 for subacromial impingement), which are fewer than the 84 shoulders of 42 athletes. These are numbers that cannot be compared directly.
That said, the picture remains significant: findings present in 96% of the shoulders examined are too common to work as an explanation for the individual case. They look more like the adaptations of tissue that works hard, like the calluses on the hands of a climber, than like a fault. Finding them on an ultrasound does not automatically mean you have found the cause of your pain.
However, what the authors concluded must also be reported in full, because it does not match this reading: in their words, the high prevalence of rotator cuff and biceps tendinopathy was associated with more symptoms. In the same study, tendinosis was more frequent in those with a positive sulcus sign, meaning more marked looseness of the shoulder, and impingement was more frequent in those with a partial rotator cuff tear. These are nonetheless clues, not causal certainties: it is a cross-sectional study, which takes a snapshot of one moment and cannot say what comes first. The honest summary is this: those findings are too common to be used alone as a diagnosis, but they are not irrelevant either, as is sometimes said.
If you want to explore the concept and its limits, we discuss it in detail in the article on shoulder impingement.
What research says about risk factors (and why it is surprising)
Here comes the finding that should change the way we read all articles on this subject, this one included.
In 2023 the Scandinavian Journal of Medicine & Science in Sports published a systematic review of risk factors for shoulder pain and injury in competitive swimmers: 1,356 studies screened, 22 included in the final synthesis. The result is clear and disorienting: for none of the 80 variables examined was there strong evidence, either for or against an association with pain or injury.
More than that. Some of the most repeated explanations received moderate evidence against an association: internal and external rotation of the shoulder, the hand-behind-the-back test, training frequency, specialty stroke, height and weight, sex and age. Put simply: the idea that someone who does butterfly or intense freestyle is therefore more at risk, or that a certain mobility measured on dry land predicts pain, does not survive the test.
Only two elements received moderate evidence in favour: competitive level (in a non-directional way, that is, without saying whether a higher level means more or less risk) and muscle recruitment profiles, for example greater activity of the serratus anterior. And the highest-quality study included in the review, conducted on 201 athletes, suggested that a high acute-to-chronic load ratio and reduced strength endurance of the posterior shoulder muscles are associated with injury.
What do we do with all this, if our shoulder hurts after swimming? Three concrete things:
- Be wary of anyone who points to a single cause. Your shoulder does not hurt "because of the scapula" or "because of a short pectoral". Anyone who tells you so with certainty is going beyond the data.
- How the load changes matters more than the absolute load. The most solid signal concerns spikes, not volume as such.
- The endurance of the posterior muscles is the most promising modifiable target. The authors of the review identify it as the modifiable intrinsic risk factor "potentially most relevant from a clinical point of view": a candidate, not a certainty. And it is not about "strength" in general, but about the ability to sustain many movements before giving way.
Symptoms: how it presents
An important tip: before trying these exercises, make sure you have received a correct diagnosis. People often think they have one problem, but the real cause of the pain is something else. Doing the wrong exercises can make things worse instead of better.
The typical picture of swimmer's shoulder is fairly recognisable, although none of these elements on its own is diagnostic.
Pain during the stroke. This is the entry symptom. It often appears at a precise point in the movement, and the instinctive first reaction is to change technique to get around it: the elbow is lifted, the trunk rotates more, the pull is shortened. The compensation works for a few lengths and then presents the bill.
Pain in the recovery, when the arm leaves the water. Many describe it as the worst moment.
Night pain. It should be watched carefully. If it is linked to position, that is, it appears when you lie on the shoulder and goes away when you switch sides, it is information about load. If instead it does not ease in any position, it falls under the signs on the list at the top of this page.
Morning stiffness that loosens with movement, with the feeling that you have to "warm up" the shoulder before it responds normally.
A feeling of weakness or giving way, especially in the final part of training, when keeping good technique becomes tiring. This is consistent with the finding about the endurance of the posterior muscles.
Clicks and crepitus. In clinical practice they are found constantly even in shoulders that do not hurt, and we do not have a specific source on swimmers that quantifies how often they occur. The practical criterion remains: on their own they say little, they matter if accompanied by pain or loss of function.
Managing the load: the lever with the most solid signal
If I had to choose only one thing to work on, it would be this.
The 2020 review on training volume observed differences in exposure between swimmers with and without shoulder pain, both in adolescents and in masters athletes. In adolescents, weekly volume and years of competitive activity correlated significantly with the thickness of the supraspinatus tendon, and all swimmers with tendon thickening had pain. The average volumes reported were about 17 hours a week between 15 and 17 years old and about 27 hours between 18 and 22. The authors recommend monitoring training all year round and avoiding sudden, large increases in volume, but they are explicit in saying that threshold values on which to base decisions do not yet exist.
This is why you will not find the famous "10% a week rule" in this article. It is a common practical rule that is comfortable to remember, but it has not been validated in swimming and no serious study supports it as a safety threshold. The principle underneath is instead reasonable: tissues adapt if the load grows gradually and predictably, and suffer when it changes suddenly.
In practice this means:
- Be careful at team transfers, training camps and returns. These are the moments when the load jumps, and it is consistent with the finding about the acute-to-chronic ratio.
- Introduce paddles and resistance equipment gradually. Not because a study demonstrates it, but because they increase the load per stroke and therefore fall within the logic of spikes.
- Returning after a break does not start from the volume you had before. This is perhaps the most common mistake.
- Keep a minimal diary. Lengths, how the shoulder feels, hours. It serves you to notice spikes before they become pain.
Exercises: what is studied and what is not
A 2022 scoping review in the Journal of Sport Rehabilitation gathered 14 studies on therapeutic exercise in competitive swimmers, that is, on the most common way of addressing swimmer's shoulder. The picture is encouraging but has to be read in full.
On one side, programmes of 6-8 weeks that combine strengthening of the external rotators and scapular retractors with stretching of the pectorals can reduce the incidence of shoulder pain in swimmers, and combining exercises and stretches with manual therapy techniques can help reduce pain in those who already have it. Dry-land work and open-chain kinetic exercises were superior to closed-chain work and work in the water for improving the strength and endurance of the external rotators.
On the other side, the point that is usually not reported: in strengthening programmes beyond 12 weeks, peak strength of the external rotators, endurance and the ratio between external and internal rotation increased, but this was not associated with a reduction in pain. The authors themselves call for caution because of the methodological limits of the included studies. Put directly: becoming stronger is documented, whether becoming stronger removes the pain is much less so.
The best evidence we have on a prevention programme comes from another sport. A cluster-randomised study from 2017 in the British Journal of Sports Medicine involved 45 elite handball teams, 660 players, followed over a 7-month season. The programme, carried out three times a week during the warm-up, brought the average prevalence of shoulder problems from 23% in the control group to 17% in the intervention group, with a 28% lower risk. For problems defined as "substantial" the difference, from 8% to 5%, did not reach statistical significance (22% lower risk, OR 0.78; 95% CI 0.53-1.16; p = 0.23). It is handball, not swimming, and the movement is different: it should be taken as an indication of direction, not as transferable proof. And it is in any case a modest effect, not the elimination of the problem.
On dosages you will not find sets and repetitions here. Not because schemes used in clinic do not exist, but because there is no study from which to derive them for your case, and inventing them would give false precision. The criterion I use with patients is simpler and more honest: work until a clear fatigue without exceeding a mild discomfort, and assess the shoulder the next day. If the next day it is worse, the load was too much.
Here are six exercises that make up a programme consistent with the above.
1. External rotation with a band. Elbow bent and resting against the side, you rotate the forearm outwards against resistance. It is the central movement of strengthening the external rotators, the component most present in the programmes studied on swimmers.
2. External rotation lying down, with prolonged fatigue. Same direction of movement but with a low load and many repetitions, aiming for endurance rather than peak strength. The endurance of the posterior muscles is the modifiable factor that the 2023 review identifies as potentially most relevant in clinic.
3. Prone Y-T-I. Lying face down, you raise your arms forming the three letters. It activates the scapular retractors and stabilisers, the other component of the programmes that have shown effects.
4. Pectoral stretch at the doorframe. With your forearm resting on the doorframe, you rotate your trunk until you feel tension in the front. Hold it as long as the tension remains tolerable, without pain.
5. Cross-body stretch. You bring the arm across the chest and guide it with the other hand. The choice here is not random, and I explain it below.
6. Thoracic rotations. On all fours or in the 90/90 position, you rotate the trunk, bringing the arm upwards. It is mobility work that makes sense for those who spend hours in flexion, although it has not been shown to prevent shoulder pain.
Why you will not find the sleeper stretch
In most articles on this topic the sleeper stretch is mandatory. A systematic review of randomised trials published in 2017 in the Journal of Sport Rehabilitation did however find moderate evidence that the active sleeper stretch may be no more effective than doing nothing in improving posterior stiffness and internal rotation deficit in the short term. For the cross-body stretch, by contrast, the same review found moderate evidence of immediate and short-term positive effects, with an important limit: the studies were on young asymptomatic subjects, not on people in pain.
So: cross-body stretch instead of the sleeper, knowing that we are extending to people who are in pain a result obtained on people who were not. It is the real level of certainty, not a better one.
If you want a wider progression of dry-land work, we have gathered it in the guide to strengthening exercises for the shoulder.
If the pain is already there
Relative rest, not total stop. It is rarely necessary to stop completely. Reducing volume and intensity, removing the sets that provoke the symptom and using the time for dry-land work is the most sensible approach, and it has the advantage of not letting conditioning collapse. It should be said that this is a choice of clinical common sense, not a finding: among the sources cited at the bottom of this page, none compared relative rest with complete rest in swimmers with shoulder pain.
Change stroke. Backstroke is often better tolerated because the shoulder works in a different position. Be careful, however: the 2023 review found moderate evidence against the idea that specialty stroke is in itself a risk factor. Changing stroke serves to remove the movement that hurts you now, not because one stroke is intrinsically dangerous.
Work on technique. A coach who watches your swimming can spot compensations that have settled in to get around the pain. It is an intervention that makes sense, but it must be said that there is no solid evidence that correcting technique reduces pain: it falls among the plausible things that have not yet been proven. Indeed, the 2023 review found no strong evidence in favour of any technical variable as a risk factor.
Managing the symptom. Ice, any medication if the doctor prescribes it, sleep management. They serve to make the weeks in which you reduce the load manageable, not to treat the tissue.
Get assessed if nothing moves. If after a few weeks of load management and targeted work the picture is unchanged, it is time for a proper assessment, which also includes the neck: some shoulder pain starts there.
What I do not promise you
Swimmer's shoulder, under this name, does not have a proven treatment pathway. What we have is: a high but very variable prevalence, imaging findings so widespread that they do not distinguish who is in pain, a list of risk factors for which research does not yet have strong evidence, and exercise programmes that improve strength and endurance with uncertain effects on pain.
That is not little. It means the reasonable path is to manage loads with attention to spikes, build endurance in the posterior muscles of the shoulder, keep symptoms under control and get assessed when something does not add up. It also means that anyone who promises to eliminate the pain in a precise number of weeks, with a precise list of exercises, is saying more than what is known.
Professional support
The value of a well-made assessment in this scenario does not lie in finding a hidden cause: it lies in ruling out what needs to be ruled out, understanding at what point in the stroke and in what load context your pain appears, and building a progression you can carry on without making things worse.
With Ri-Hub you can do this from home, by video call. Our physiotherapists know the needs of people who swim and the real picture of the evidence on swimmer's shoulder, and can guide you through carrying out the exercises, correct what needs correcting and adapt the progression week by week according to how the shoulder responds. Tele-rehabilitation is particularly suited to a pathway of this kind, because it is made mostly of exercise and of managing the load over time.
Sources
- Shoulder pain and injury risk factors in competitive swimmers: A systematic review, Scandinavian Journal of Medicine & Science in Sports, 2023
- Clinical and Ultrasonographic Evaluations of the Shoulders of Elite Swimmers, American Journal of Sports Medicine, 2016
- Swim-Training Volume and Shoulder Pain Across the Life Span of the Competitive Swimmer: A Systematic Review, Journal of Athletic Training, 2020
- The Effect of Exercise Therapy Interventions on Shoulder Pain and Musculoskeletal Risk Factors for Shoulder Pain in Competitive Swimmers: A Scoping Review, Journal of Sport Rehabilitation, 2022
- Preventing overuse shoulder injuries among throwing athletes: a cluster-randomised controlled trial in 660 elite handball players, British Journal of Sports Medicine, 2017
- Effectiveness of Stretching on Posterior Shoulder Tightness and Glenohumeral Internal-Rotation Deficit: A Systematic Review of Randomized Controlled Trials, Journal of Sport Rehabilitation, 2017
Last source check: August 2026.
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