Swimmers Shoulder is an umbrella term for shoulder pain incurred from greater training demand, inappropriate load or impaired joint biomechanics during the swim stroke. Pain will typically present in the anterolateral shoulder as a result of impingement, rotator cuff tendinopathy or tear, labral injuries or neurological impingement. Each stroke varies in the musculoskeletal demands which can be refined to ensure performance optimisation.
The Shoulder
The Shoulder Joint encompasses the junction where the Upper Arm Bone (Humerus) meets the Collar Bone (Clavicle) and the Shoulder Blade (Scapula) at the back. The Glenohumeral Joint is an inherently unstable ball and socket joint to allow for a large range of motion. The Labrum sits within the Socket of the Shoulder Blade, creating a smooth surface for the Humeral Head to glide on. Ligaments reinforce these bony junctions and muscles attach to the bone through tendons. The muscles cross each joint to generate movement and provide stability. The Rotator Cuff muscles as pictured below, are comprised of the Supraspinatus, Infraspinatus, Subscupularis, Teres Minor. There are multiple additional muscles that attach onto the shoulder which will be discussed in further detail relative to the stroke.
Swimming Biomechanics
Swimmers will clock between 6 and 8 km’s each week, requiring an average of 3km’s per arm. Whilst swimming involves a kick from the lower limb, about 90% of force is generated from the upper limb. To optimise stroke efficiency, full range of motion is desired with strength from the musculotendinous unit to support same.
Freestyle can be broken into the following phases:
- Hand entry marks the beginning of the freestyle stroke cycle. The hand reaches the water with the elbow is positioned slightly higher than the hand itself. The palm is facing down.
- Forward reach or glide is the second phase where the Upper Trapezius, Serratus Anterior and Rhomboids allow for the upward rotation of the Scapula on the Humeral Head.
- Pull through: this component is where swimmers will most commonly experience pain/shoulder symptoms and can be broken into 3 phases.
- Early phase begins once the shoulder has reached maximum forward reach at the end of the glide phase. The elbow stays high and the shoulder begins to internally rotate using both the Pectoralis Major and Teres Minor.
- Mid phase is where the forearm becomes perpendicular to the trunk with the finger tips directly pointing to the bottom of the pool. The Pec remains active and the Serratus Anterior switches on with the Latissimus Dorsi to pull body over the top of the arm.
- Late phase is where the forearm moves through to an extended position parallel to the trunk which is again facilitated by the Lats. This activation pattern also assists with Subscapularis finalising the pull through.
- Exit: the elbow will emerge from the water first during the exit, softly bent before the hand.
- Recovery phase: the Glenohumeral Joint moves into extension and abduction from the Deltoid and Supraspinatus. The rhomboids will draw the Scapula inward to assist with trunk rotation. The final recovery phase utilises the anterior deltoid before resuming the cycle for hand entry.
This cycle is completed simultaneously with a kick which involves hip flexion/extension and weak knee flexion and extension. A 2x beat kick would mean a single kick on each limb during one stroke cycle which will optimise stroke efficiency. Increasing the kick rate will improve propulsion but use more energy.
Shoulder Pain
As aforementioned, pain is most commonly reported during the pull through phase of the swim cycle. Symptoms may present as a pain or pinching through the top of the shoulder. There may also be complaints of clicking/catching or locking that is painful during stroke.
Through swim analysis, there are some key stroke failures which present in those with Swimmers Shoulder such as:
- Dropped elbow during early pull through
- Greater shoulder abduction
- Early exit with reduced shoulder internal rotation
- Lateral hand entry
It is unclear whether these stroke failures/modifications are the sequelae of a pain syndrome or predisposing the swimmer to shoulder pain.
Causes of Swimmers Shoulder
Impingement is the predominant diagnosis seen in this population which can be primary or secondary. Primary impingement occurs where the Rotator Cuff tendon, Biceps Tendon or the Subacromial Bursa becomes compressed between the Acromion and Humerus. A tight posterior capsule or increased anterior Glenohumeral Joint laxity can cause this compression however it is less common than secondary impingement.
Secondary impingement typically results from joint laxity, impaired Scapula mechanics or fatigue/weakness through the dynamic stabilisers- the Rotator Cuff muscles. Impaired Rotator Cuff and Serratus Anterior strength inhibits the upward rotation of the Scapula and increase load anteriorly on the Pectoralis. Without correct activation of the Serratus Anterior, the Subacromial Space becomes compromised and the Glenohumeral Joint laxity increases. Joint laxity through the Glenohumeral Joint can increase the anterior translation of the Humerus subsequently reducing shoulder internal rotation and increasing external rotation.
So what causes these biomechanical failures?
Changes in load from training intensity, duration or frequency can be enough to change the demand on the musculoskeletal structures. Increases in swim volume, tissue load with paddles, drills or speed work can overload and subsequently fatigue the rotator cuff muscles. Without adequate rest and recovery strategies, tendinopathies or impingement patterns can develop.
Physiotherapy Assessment
Your Physiotherapist will complete a thorough subjective an objective assessment to rule out other possible diagnoses. The objective assessment will review posture, joint range of motion, strength of the primary working muscle groups and an assessment on joint laxity or hypermobility. These objective assessment tools will aid in formulating a rehabilitation plan.
It is important to discuss the specifics of the athletes training load, session structure and conduct a stroke analysis to assist with de-loading or modification as seen in the treatment options.
Treatment
Manual Therapy: hands-on Physiotherapy techniques such as soft tissue release, joint mobilisations, mobilisation with movement, muscle energy techniques and taping. Athletes will often value symptom management over further intervention to continue training or competing.
Rehabilitation: is an individualised program encompassing both strength and mobility exercises depending on the findings deduced from the objective examination. Mobility and release style techniques incorporate thoracic mobility; extension and rotation with adequate length encouraged through the pectoral muscles and posterior shoulder capsule.
Strength exercises in the context of rehabilitating an injury focus on Scapula stability and the associated activation of the Rhomboid, Middle and Lower Trapezius and Serratus Anterior musculature. Most exercises are completed in a face-down position to facilitate sport specific retraining and are gradually progressed from isometric/activation style exercises to dynamic stability with greater demand. Rotator Cuff strengthening is also vital for performance and should move through isometric, eccentric, concentric and plyometric training styles.
Load Management: your Physiotherapist will discuss principles of abuse, misuse and overuse relevant to your presentation. Appropriate modifications to technique, equipment, intensity and volume will be made where necessary.
Surgical Intervention may be considered when conservative management techniques have failed and the swimmer has an inability to compete or engage in day to day activities. Instability may warrant surgical capsular stabilisation techniques whereas persistent pain and restriction may support arthroscopic investigation for a debridement.
Your Physiotherapist and General Practitioner may encourage referral to a Sports Physician prior to Orthopaedic review to discuss the nuances between clinical presentation and non-conservative outcomes and risks. Ultimately, the individual should feel supported and empowered by the treating team with a clear understanding of goals and time-frame for recovery.
References:
- Davis DD, Nickerson M, Varacallo M. Swimmer’s Shoulder. [Updated 2023 Nov 22]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2024 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK470589/
- Heinlein SA, Cosgarea AJ. Biomechanical Considerations in the Competitive Swimmer’s Shoulder. Sports Health. 2010 Nov;2(6):519-25. doi: 10.1177/1941738110377611. PMID: 23015983; PMCID: PMC3438875.
- Tovin BJ. Prevention and Treatment of Swimmer’s Shoulder. N Am J Sports Phys Ther. 2006 Nov;1(4):166-75. PMID: 21522219; PMCID: PMC2953356.