INCUS Performance Blog – Shoulder injuries in Swimmers!

Recently I had the privilege of being asked to write some guest content for INCUS performance. INCUS are a wearable tech company who manufacture smart devices for swimmers and runner to monitor their performance economy. They asked INVICTA to write some informative content related to swimming injuries and their management. Below is the full content of the blog. If you’re a swimmer this is a MUST READ!

What are the most common injuries you see among swimmers?

In clinic I most commonly see shoulder and back issues amongst swimmers. With shoulders its classically those associated with overuse such as subacromial impingements and tendinopathies of the rotator cuff or long-head of biceps and sometimes these can be associated with labral tears. In the back its much of the same, overuse and fatigue patterns leading to heightened muscle tone in the hip flexors and lower back extensors. This can lead to extension related back pain caused by compression of the lumbar facet joints. Often both classifications of injury are non-time loss in nature and most patients are still able to swim with discomfort. Given the correct advice and management strategies early reduces to burden of injury in these patients.

What is ‘swimmer’s shoulder’?

Swimmers shoulder is an umbrella term for pathologies of the shoulder. These pathologies include impingement mechanisms, tendinopathies, labral injuries, shoulder instability secondary to laxity or muscular imbalance, neuropathies and pain arising from anatomic variation/change. The problem with the term “swimmers shoulder” is it is anatomically non-specific, as a diagnosis it doesn’t give you an indication into what is the pain generating structure which ultimately influences the management. That is why it is important to see a physiotherapist to get a clinical diagnosis which can be confirmed with diagnostic imaging if necessary.

What causes ‘swimmer’s shoulder’?

It really depends on the patient, their injury history, anatomy, physical qualities, and training loads. Often hypermobility, muscular imbalance or poor scapula mechanics can predispose patients to an increased risk of subacromial impingement for example. But if you have an instability caused by a labral tear you developed after falling off your bike during triathlon training then that can create a whole different pain experience.

However, regardless of mechanism, a lot of “swimmers shoulder” injuries are driven by overuse and repetition. There’s some evidence in elite swimmers logging 60,000 – 80,000 meters in the pool per week, this equates to 30,000 strokes per arm! And with around 90% of the propulsive forces in swimming coming from the shoulder it’s a big demand for the relatively small anatomy that is often injured.

What are the dos and don’ts swimmers should look out for to prevent developing swimmer’s shoulder?

DO – begin to understand your own weaknesses, movement restrictions and inefficiencies around the shoulder by seeing a physiotherapist and then try to remedy these in a gym-based training programme. For example – at Invicta, we would perform an upper body movement screen and strength assessment of the rotator cuff and scapular-thoracic muscles using objective testing, we’d then create a training plan for you with reassessments to monitor progress.

DO – monitor your training loads in the form of external or internal loads.

External simply being total distance – so for every session write down how far you have swum in meters which can be in a training diary, notes app on your phone or on an excel spread sheet. There is a simple calculation you can perform to work out your “Acute Chronic Workload Ratio” which gives you a reflection of how much volume you’ve trained in the last week compared to an average of the last four weeks. If this number is between 0.8 – 1.3 then you’re in an optimal training zone, if this number creeps upwards of 1.5 it means that you’re spiking your training loads and increasing your injury risk! Here’s a calculation: [Last week’s training distance] ÷ [Last four weeks training distance ÷ 4] = ACWR.

Internal loads are things you perceive such as Rate of Perceived Exertion (RPE), sleep quality or muscle soreness (typically rated from 1-10) or things you monitor such as heart rate or heart rate variability which you’ll need a smart device for. Monitoring a combination of internal and external loads over time can help you make better informed decisions about your training which help you negate injury.

DON’T – ignore the initial onset of symptoms and continue to swim. Often the main driver of pain in swimmers shoulders is inflammation. If this isn’t respected and managed early enough a seemingly low irritability injury can be exacerbated through continued training, which means it takes longer to settle down with more complications in the long run. To manage the primary inflammation, take NSAIDs and rest, to manage the secondary pain and muscle tone use ice and see a physio for treatment and guidance on rehabilitation.

What is shoulder impingement?

Shoulder impingement falls into two distinct categories: internal impingement and subacromial impingement (external). Internal impingement is where the posterior rotator cuff muscles (infraspinatus / supraspinatus) impinge against the glenoid (socket) with patients reporting pain in the posterior-superior shoulder. External impingement occurs when the supraspinatus tendon or subacromial bursa is impinged against the underside of the acromion (bony process on the scapula) creating a more anterior-superior pain location. Although compression of these structures is a natural occurrence in asymptomatic populations, repetitive microtrauma and inflammation can produce a heightened pain response.

What causes shoulder impingement?

Internal impingement is usually due to shoulder instability caused by a labral tear, ligament laxity or ineffective co-ordination of the rotator cuff muscles that results in poor centring of the humeral head on the glenoid (ball on the socket). As the humeral head slides anteriorly on the glenoid in pinches the posterior rotator cuff muscles against the glenoid rim posteriorly. This injury mechanism is usually provoked during mid-recovery of the swim cycle, when the arm is cocked in external rotation ready to enter the water again.

Subacromial impingement (external) in keeping with the mechanisms discussed above is similarly influenced by an inability to centre the humeral head on the glenoid with a more superior translation of the humerus (the ball) abutting against the underside of the acromion (bony process on the shoulder blade). Due to the training volumes and the number of repetitive revolutions of the shoulder involved in swimming, fatigue of the rotator cuff muscles and altered shoulder girdle mechanics are the main driver of impingement. Often age-related change (acromion bone spurs, tendinopathy and calcification of the supraspinatus tendon), anatomical variance (acromion morphology) and previous injury (rotator cuff tears, labral tears) can predispose swimmers to an increased risk of recurrent subacromial impingement injuries. Subacromial impingement is usually exacerbated from mid-recovery to hand entry in the swim cycle and to compensate swimmers may observe a lower elbow lift and an early hand entry into the water on that side.

What are the dos and don’ts swimmers should look out for to prevent developing shoulder impingement?

DO – invest your time into strength training. Expose the rotator cuff and scapulothoracic muscles to a loading stimulus that isn’t in the pool. Improving the strength and capacity of these muscle is your biggest insurance policy against impingement type mechanisms.

DO – make informed decisions about your training. Use external and internal load monitoring to influence and reflect on the volume and timing of your training. For example, if your last weeks loading was twice as much as the average of the last four weeks (using the ACWR calculation above), you rate a 9/10 on muscle soreness and you’ve had a couple of bad night’s sleep – then maybe training today isn’t the answer and a scheduled de-load with some accessory strength work in the gym is the best fit!

DO – See a coach to improve your swimming technique. Movement is a skill, the more consistently you can execute that skill means you’ll reduce the expose of your shoulder to faulty mechanics leading to impingement.

DON’T – spend too much time doing overhead activities away from swimming. Positions overhead significantly narrow the subacromial space and increase your chances of impingement. If swimming is your main pursuit four times a week and the other three days you play badminton then that’s a lot of exposure to the mechanisms that prelude impingement. If you’ve built up to this volume slowly over a long time and you are proficient mover, then you might get away with it for a time but a sudden jump into that volume of activity exaggerates the risk.

DON’T – become reliant on passive modalities and injections. If you do get symptoms, then get an accurate clinical diagnosis and management plan from a physiotherapist. This should involve correcting underlying deficits in strength and movement efficiency and should only involve passive modalities that compliment these goals. Don’t become heavily reliant on things like massage and acupuncture as they will have a short-term neurological effect that will make you feel better but are not going to resolve the underlying issue about why this has happened. And whilst injection modalities may sometimes be appropriate, they are not the magic bullet – don’t run your shoulder into the ground thinking that a simple injection will get you back to square one.  

If a swimmer does develop one of these injuries, what exercises or treatment do you recommend to help get back to optimal performance?

There is certainly not a one size fits all approach to rehab and each presentation much be treated as an isolated case with interventions tailored specific to the patient. Generally speaking – my go to areas of focus are exercises that aim to restore full functional range of motion in all planes, strength exercises targeting both sides of the rotator cuff (Internal and external rotators), scapulothoracic exercises to improve scapula-humeral rhythm and proprioceptive exercises which challenge the shoulder girdle to stabilise the ball on the socket during dynamic movement.