By James White

Published: Friday, 27 May 2022 at 12:00 am


Although triathlon’s first discipline, the swim leg, is often deemed the toughest, it’s also blessed with the lowest injury rate. They can happen, though – so we asked qualified osteopath (and former GB powerlifter) James White to look at the most common shoulder injury swimmers get: subacromial impingement, aka ‘swimmer’s shoulder’.

What is swimmer’s shoulder?

Swimming, while relatively low impact, puts your shoulder joint through a huge range of repetitive motion, which can lead to a cumulation of stress and sometimes results in pain and dysfunction. As a result, it’s very difficult to pin the cause of shoulder pain down to one specific part, and it’s instead important to take a global approach to the shoulder and torso.

Swimmer’s shoulder symptoms

Symptoms of swimmer’s shoulder can include:

The anatomy of the shoulder joint

The shoulder is a complex joint with a fantastic range of motion, as lots of structures work closely to each other, overlapping in their roles and responsibilities. However this is at the cost of stability, and is the reason shoulder injuries are fairly common, even though it’s not a weight-bearing joint.

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The anatomy of a shoulder joint

The shoulder joint is a ball and socket joint, which – unlike the hip joint – has a very shallow socket. A good way of imagining what it looks like is by thinking of a golf ball on a tee.

The bony part of your shoulder that you can feel sticking out at the end is called your acromion and this is where your collar bone meets your shoulder blade. When you lift up your arm above your head there is potential for the top of your humorous (upper arm) to knock and cause irritation against the under surface of your acromion.

There are a number of tissues that could be inflamed and causing pain. One is the bursa which is a flat sack that acts as to encourage smooth gliding of two tissues against each other. The bursa is likely to become inflamed if the shoulder is fallen on.

Another common one is the supraspinatus tendon. This is a small muscle that runs along the top of your shoulder blade and the tendon passes under the acromion and attaches onto the top of the humerous.

There is a part of the tendon called the critical zone where the blood supply is poor and this increases the chances of it becoming irritated due to its inability to heal itself quickly.

A healthy shoulder should not have any problems going through a full range of motion without any issues. It’s when poor posture (such as excessive kyphosis in thoracic spine), lack of thoracic mobility, or even poor diet contribute to the mix that things can start to get irritated and under-repaired.

How do I test to see if I have swimmer’s shoulder, aka subacromial impingement?

A simple and fairly accurate way to know if your shoulder pain is due to swimmer’s shoulder (subacromial impingement) is the painful arc test. To perform this test simply stand and raise your arm out to the side all the way above your head.