What it is

Posterior shoulder impingement occurs when the rotator cuff is compressed against the back of the glenoid during extreme abduction and external rotation. It is common in throwers and swimmers.

It reflects a blend of workload, technique, and shoulder mobility. Many improve with targeted strength and movement coaching.

What happens when it occurs

At late cocking the cuff contacts the posterosuperior labrum. Repeated exposure without control irritates the cuff. Improving scapular position, external rotation strength, and throwing mechanics reduces contact stress.

Common causes and risk factors

  • High volumes of throwing, butterfly and freestyle swimming
  • Glenohumeral internal rotation deficit
  • Scapular control deficits
  • Previous cuff or labral problems

Who is most affected

Throwers, pitchers, tennis servers, and swimmers.

Typical symptoms

  • Posterior shoulder pain during late cocking
  • Reduced power or accuracy
  • Tenderness at the back of the shoulder

When to seek care

If pain limits training or performance, or if clicking and weakness persist.

How we diagnose

Clinical tests in the position of risk, strength and range measures, and imaging when a cuff tear or labral lesion is suspected.

Management

  • Modify throwing or stroke volume and intensity
  • Strengthen external rotators and scapular stabilisers
  • Address the internal rotation deficit and thoracic mobility
  • Return to the throw programme with technique coaching

Rehabilitation milestones

Phase 1 weeks 0 to 3: pain control, restore range, technique drills at low intensity.

Phase 2 weeks 3 to 8: heavy slow strength and scapular control, interval throwing or swimming sets.

Phase 3 weeks 8 to 16: power and endurance, graded return to competition speed.

Phase 4 months 4 to 6: full competition with maintenance work.

Readiness to progress

  • Pain-free at late cocking positions
  • Strength symmetry within 90 per cent
  • Throw or swim sessions completed without next-day pain

Prevention

  • Keep external rotator strength high
  • Manage season volume with deload weeks
  • Maintain thoracic and shoulder mobility

Australia snapshot

  • Seen in swimming and throwing programmes in schools and clubs
  • Strong representation in cricket, baseball, and water polo
  • Access to sports physio and coaching support is broad

Latest insights

Position plus load equals stress. Adjust both to alleviate tension in the posterior shoulder.

Throwing and swimming mechanics decide how fast you return.

Frequently Asked Questions

Only when a cuff or labral tear is suspected or when progress stalls.

Yes, with volume and intensity adjustments and with technique drills.

External rotation and scapular drills are core parts of the plan.

Often, within months, when milestones are met.

Improve internal rotation by carefully dosing and monitoring the response.