Swimming Shoulder: The Overuse Injury of the Pool

Swimming has a reputation as the injury-free sport. It is low impact, it is kind to knees and hips, and it is the activity I most often recommend to patients who cannot tolerate running. All of which is true, and none of which protects the shoulder.

A competitive swimmer can turn over tens of thousands of strokes in a single week. Even a committed masters swimmer doing three sessions at a local pool will rack up an enormous number of overhead repetitions. Repeat any movement that many times and the tissue eventually asks for a word. That is swimmer's shoulder: not a single injury but a pattern of overuse in a joint built for mobility rather than endurance.

What swimmer's shoulder actually is

The term covers a cluster of related problems rather than one diagnosis. Most commonly it is rotator cuff related shoulder pain, an irritation of the cuff tendons, particularly supraspinatus, as they work hard to keep the ball of the joint centred in a very shallow socket. It can also involve the long head of biceps tendon, irritation of the bursa, or in swimmers with very mobile joints, a degree of instability where the shoulder simply has more range than the muscles can currently control.

The classic story goes like this. First there is an ache after hard sets only. Then an ache during the last part of every session. Then pain that starts early in the swim, and eventually pain reaching into a cupboard or sleeping on that side. Each stage takes longer to settle than the last. Catching it at stage one is enormously easier than catching it at stage four, and yet almost nobody comes in at stage one.

Why it happens

Volume that rose too fast. Far and away the most common cause. A new squad, a return after a layoff, a masters swimmer building for an event, or a triathlete adding pool work in winter. The tissue adapts, but slowly, and it dislikes sudden jumps.

Stroke mechanics. A crossover entry where the hand crosses the midline, a dropped elbow during the catch, insufficient body roll, or breathing exclusively to one side all increase the load on one shoulder. Front crawl and butterfly are the biggest offenders; breaststroke tends to bother knees more than shoulders.

Weak scapular and cuff control. Swimming trains the big pulling muscles hard and the small stabilisers barely at all. Over a season the balance drifts, and the muscles that hold the shoulder blade steady fatigue before the ones driving the stroke do.

Kit choices. Hand paddles are the usual suspect. They increase the force through the shoulder on every stroke, and a lot of shoulders first complain within a fortnight of paddles appearing in the kit bag. Pull buoys have a similar effect by removing the legs and loading the arms more.

Poor recovery. Two sessions in a day, a heavy gym block landing on the same tissue, and too little sleep all shrink the margin.

What to do when it starts hurting

You do not usually have to stop swimming altogether, which is the fear that keeps people quiet about it. What you have to do is change the load.

• Cut the aggravating volume, not necessarily all volume. Reduce front crawl distance, drop the paddles and pull buoy entirely, and add more kick sets.
• Change stroke selection. Backstroke and breaststroke are often far better tolerated while crawl is irritable.
• Stop on sharp pain. A dull ache that settles within an hour of finishing is workable. Pain that keeps you awake or that is worse the next morning means you have overshot.
• Do not stretch into the pain. Swimmers are usually mobile enough already. More stretching of an irritable, hypermobile shoulder rarely helps; strength does.
• Start loading the cuff. External rotation with a band at the side, then at 90 degrees of abduction, plus scapular work such as prone Ys and Ts and serratus punches. Three sessions a week, controlled tempo, mild fatigue rather than pain.

If it has been grumbling for more than three or four weeks despite sensible adjustments, get it assessed. An accurate diagnosis matters here, because instability, cuff tendinopathy and a genuine tear all look similar from the pool deck and need different plans. My shoulder injury page explains what an assessment covers.

Preventing it in the first place

Build volume gradually. The pool is not exempt from load management. Increase weekly distance in steps rather than jumps, and be especially careful in the first fortnight back after a break.

Do the boring gym work. Two short sessions a week of rotator cuff, scapular and thoracic mobility work is the highest-value insurance a swimmer can buy. It takes twenty minutes.

Breathe bilaterally in training. Even if you breathe to one side when racing, alternating in training spreads the load and improves symmetry.

Get a stroke check. A coach's eye on your catch and body roll will often find the thing no amount of band work fixes.

Earn your paddles. Introduce them in small doses, late in a training block, never in week one back.

When to see a doctor

Seek medical assessment rather than carrying on if you cannot lift the arm at all after an acute injury, if you have significant weakness rather than just pain, if the shoulder feels like it slips or gives way, or if you have night pain that is severe and unrelenting, particularly alongside unexplained weight loss.

Swimming in Liverpool and Merseyside

There is no shortage of water around here, from the council pools across the city to the open water swimming that has grown enormously in the North West. Autumn is when a lot of triathletes and open water swimmers move back indoors and quietly triple their pool volume in a fortnight, which is precisely the pattern that produces a sore shoulder by November. If that is you, phase the transition over three or four weeks.

I treat a good number of swimmers across Liverpool and Merseyside, and the pattern is nearly always fixable once we identify which part of the load is doing the damage. You can read more about how I approach sports injury rehabilitation, and if you train away from the city, an online consultation works well for stroke-related shoulder problems because so much of it is assessment and programming.

Home visits across Liverpool and Merseyside are £90 a session and online video consultations are £60, evenings Monday to Friday, plus Saturday and Sunday daytimes, with no GP referral needed. Book at /portal/book or call me on +44 7443 357020.