Swimmer’s Shoulder: Causes and Prevention

Swimmer’s shoulder

Swimmer’s shoulder is the term used to describe shoulder pain associated with swimming, which represents the most frequent musculoskeletal problem in this sport. It is estimated that 40-91% of competitive swimmers develop shoulder pain during their career. A competitive swimmer performs approximately 1-2 million strokes per year, subjecting the shoulder to enormous repetitive mechanical stress. Understanding the specific mechanisms of swimming and adopting targeted preventive strategies are fundamental for the health of the swimmer’s shoulder.

Why the Shoulder is so Vulnerable in Swimming

Swimming is a predominantly overhead activity that requires the shoulder to have:

• Wide range of motion in all directions
• Strength for propulsion through water (the shoulder generates 90% of propulsion in freestyle)
• Endurance for thousands of consecutive strokes
• Dynamic stability in positions of great mechanical vulnerability

During the stroke, the shoulder goes through phases of extreme abduction-external rotation (recovery) and adduction-internal rotation under load (catch and pull), creating conditions for subacromial impingement and stress on the rotator cuff.

Shoulder Pathologies in Swimmers

Subacromial Impingement

Compression of the rotator cuff tendons under the acromion during the recovery phase of the stroke (arm overhead). It is the most frequent cause of shoulder pain in swimmers.

Rotator Cuff Tendinopathy

Overload degeneration of the supraspinatus, infraspinatus, and subscapularis tendons due to thousands of repetitive strokes.

Glenohumeral Instability and Laxity

Many swimmers have physiological joint hyperlaxity that allows for a wide range of motion but predisposes to microinstability, with recurrent subluxation and stress on the capsule and glenoid labrum.

GIRD (Glenohumeral Internal Rotation Deficit)

Posterior capsular tightness causes a loss of internal rotation and a superior shift of the humeral head’s center of rotation, promoting impingement.

Glenoid Labrum Tear (SLAP)

Repetitive traction of the biceps during the pull phase can cause a superior labral tear.

Risk Factors

Training-related factors

Biomechanical factors

• Incorrect technique: thumb-first hand entry, low elbow during recovery, hand crossing over the midline
• Unilateral breathing: muscular imbalance and asymmetrical trunk rotation
• Weakness of external rotators: imbalance between internal rotators (strong for propulsion) and external rotators (weak because less challenged)
• Weakness of scapular stabilizers: the scapula does not adequately support humeral movements
• Reduced thoracic mobility: thoracic stiffness limits the extension and rotation necessary for an efficient stroke
• Reduced internal rotation mobility: GIRD

Individual factors

• Joint hyperlaxity (frequent in swimmers)
• Female gender
• Previous shoulder injuries
• Scapular dyskinesis (altered scapular movement)

Symptoms

• Anterior and/or lateral shoulder pain during or after swimming
• Pain during the catch and pull phase (arm pulling forward)
• Pain during the recovery phase (arm out of the water)
• Night pain after intense training
• Typical progression: pain only after training → pain during training that improves with warm-up → constant pain during swimming → pain at rest
• Loss of stroke power
• Feeling of a “dead” or unstable shoulder

Diagnosis

Clinical examination

• Impingement tests (Neer, Hawkins-Kennedy)
• Assessment of internal and external rotation (bilateral comparison, search for GIRD)
• Rotator cuff tests (Jobe, Patte, lift-off)
• Stability assessment (apprehension, relocation, load and shift test)
• Scapular assessment: dyskinesis, scapular assistance test
• SLAP tests (O’Brien, anterior slide)

Instrumental examinations

• Ultrasound: dynamic assessment of the cuff and bursa
• Magnetic Resonance Imaging (MRI): for labral tears, partial rotator cuff tears, bone edema
• X-ray: excludes bone abnormalities, hooked acromion

Treatment

Training load management

• Reduce total volume by 30-50% during the painful phase
• Temporarily eliminate paddles, pull buoy, and painful strokes
• Prioritize less stressful strokes: backstroke (less impingement), legs
• Maintain aerobic training: stationary bike, light running if tolerated

Physiotherapy

Phase 1 — Pain reduction (weeks 1-4):

• Cryotherapy after training
• Manual therapy: glenohumeral mobilization, posterior capsule release, thoracic spine mobilization
• Posterior capsule stretching: sleeper stretch, cross-body stretch. 3&215;30 seconds
• Kinesio taping to facilitate scapular posture

Phase 2 — Correction of imbalances (weeks 4-12):

External rotator strengthening:

• External rotation with elastic band at 0°: 3&215;15
• External rotation at 90° abduction: 3&215;12
• Side-lying external rotation with dumbbell: 3&215;12

Scapular stabilization:

• Elastic band rowing: 3&215;15
• Prone Y-T-W: 2&215;10 per position
• Push-up plus: 3&215;12
• Serratus punch: 3&215;12

Thoracic mobility:

• Foam roller extension: 2&215;10
• Quadruped thoracic rotations: 2&215;10 per side
• Open book stretch: 3&215;30 seconds per side

Core:

• Front and side plank
• Elastic band rotations (simulate swimming torsion)

Phase 3 — Return to full swimming (from 3 months):

• Gradual reintroduction of painful strokes
• Progressive introduction of paddles (not before full strength recovery)
• Symptom monitoring with pain rule < 3/10
• Correction of swimming technique with the coach

Technique correction

Errors to correct:

• Thumb-first hand entry → finger-first entry
• Low elbow during recovery → high elbow
• Hand cross-over → hand enters in line with the shoulder
• Breathing only on one side → bilateral or alternating breathing
• Straight arm pull → high elbow in the underwater phase

Other Swimming Injuries

Breaststroker’s knee

Pain in the medial compartment of the knee caused by the breaststroke kick, which involves forced external rotation of the tibia with hip abduction. It can involve the medial collateral ligament, medial meniscus, and pes anserine tendons.

Prevention:

• Strengthening of hip stabilizers
• Correct breaststroke kick technique
• Reduce breaststroke volume during symptomatic phases

Low back pain

Swimming itself is generally protective for the back, but starts from the blocks (hyperextension), butterfly, and backstroke with incorrect technique can cause low back pain. The prolonged hyperlordotic position in butterfly is the main mechanism.

Foot and ankle injuries

• Anterior tibialis tendinitis: due to repetitive dorsiflexion in breaststroke
• Foot cramps: due to forced plantarflexion in freestyle and backstroke

Prevention Program

Pre-training (5-10 minutes)

• Thoracic spine mobilization (foam roller, rotations)
• Cuff activation: light elastic band external rotation (2&215;10)
• Scapular activation: light rowing, prone Y (2&215;10)
• Progressive light swimming (200-400 m easy mixed stroke)

Dry-land training (2-3 times/week)

• External rotation with elastic band: 3&215;15
• Sleeper stretch: 3&215;30 seconds
• Prone Y-T-W: 2&215;10
• Push-up plus: 3&215;12
• Core stability: plank, dead bug. 3&215;30 seconds
• Squats and lunges: 3&215;12 (general strength)

Volume management

• Maximum volume increase 10% per week
• Limit paddle use to less than 25% of total volume
• Alternate different strokes to distribute stress
• Include at least one full rest day per week
• Bilateral breathing during warm-up and cool-down

Frequently Asked Questions (FAQ)

Frequently Asked Questions

What is the role of dry-land training in preventing swimmer’s shoulder?

Dry-land training is crucial for developing shoulder stability and strength, particularly targeting external rotators and scapular stabilizers. This type of training helps to balance muscle groups and improve overall shoulder resilience against the repetitive stresses of swimming.

How is Swimmer’s Shoulder typically diagnosed?

Diagnosis of Swimmer’s Shoulder involves a comprehensive clinical examination by a healthcare professional to assess range of motion, strength, and specific pain patterns. Instrumental examinations, such as MRI or ultrasound, may also be utilized to confirm the diagnosis and identify underlying structural issues.

What are the primary treatment approaches for Swimmer’s Shoulder?

Treatment for Swimmer’s Shoulder typically involves managing training load, engaging in targeted physical therapy guided by a physical therapist, and correcting swimming technique. These interventions aim to reduce inflammation, restore proper biomechanics, and gradually return the individual to activity.

What biomechanical factors contribute to the vulnerability of the shoulder in swimming?

The shoulder’s vulnerability in swimming is often linked to the highly repetitive overhead motion and the significant mechanical stress placed on the joint. Factors such as reduced thoracic mobility, unilateral breathing patterns, and imbalances in muscle strength can exacerbate this vulnerability.

Sources and Scientific References

1. Matzkin E et al. (2016). Swimmer’s Shoulder: Painful Shoulder in the Competitive Swimmer. J Am Acad Orthop Surg. 24:527-36. DOI | PubMed
2. Raffini A et al. (2024). Impact of Physiotherapy on Shoulder Kinematics in Swimmers with Swimmer’s Shoulder Pain. Sensors (Basel). 24. DOI | PubMed
3. Ciullo JV (1986). Swimmer’s shoulder. Clin Sports Med. 5:115-37. PubMed
4. Feijen S et al. (2020). Swim-Training Volume and Shoulder Pain Across the Life Span of the Competitive Swimmer: A Systematic Review. J Athl Train. 55:32-41. DOI | PubMed
5. Yoma M et al. (2022). The Effect of Exercise Therapy Interventions on Shoulder Pain and Musculoskeletal Risk Factors for Shoulder Pain in Competitive Swimmers: A Scoping Review. J Sport Rehabil. 31:617-628. DOI | PubMed