Internal Impingement (Throwers Shoulder)

Internal impingement is a condition unique to overhead athletes — particularly throwers and tennis players — in which the posterior rotator cuff and posterosuperior labrum are pinched between the humeral head and glenoid when the arm is in the late cocking position. It is a leading cause of shoulder pain in competitive throwers.

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Typical Recovery Time

3–6 months; season management often required for throwers

Symptoms

•Posterior shoulder pain in the late cocking phase of throwing
•Pain at maximum external rotation
•Decreased throwing velocity or accuracy
•Night pain in the posterior shoulder
•Posterior shoulder tightness (glenohumeral internal rotation deficit)

Common Causes

•Repetitive overhead throwing creating posterior pinching
•Glenohumeral internal rotation deficit (GIRD)
•Posterior shoulder tightness
•Scapular dyskinesis
•Anterior capsule laxity allowing excessive external rotation

Treatment Options

1Posterior shoulder and sleeper stretches to correct GIRD

2Scapular stabilization and rotator cuff program

3Throwing mechanics assessment and correction

4Activity modification during acute phase

5Arthroscopic debridement for labral or cuff damage in refractory cases

When to See a Doctor

See a sports medicine provider familiar with overhead athletes if you have posterior shoulder pain during the cocking phase of throwing.

Frequently Asked Questions

What is internal impingement of the shoulder?

Internal impingement is a condition where the rotator cuff and labrum get pinched inside the shoulder during overhead motion. It is most common in throwing athletes. This can lead to pain and decreased performance.

What causes internal impingement?

It is usually caused by repetitive overhead activity such as throwing or serving. Poor shoulder mechanics and tightness in the back of the shoulder can increase the risk. Over time, this leads to irritation of the rotator cuff and labrum.

What are the symptoms?

Symptoms include deep shoulder pain, especially during the late phase of throwing. Athletes may notice decreased velocity or control. Pain is often worse with overhead or rotational movements.

How is it treated?

Treatment focuses on physical therapy to improve shoulder mechanics, flexibility, and strength. Rest from aggravating activities is important early on. Most athletes improve without surgery.

When can I return to sports?

Return to sport depends on restoring proper mechanics and eliminating pain. Many athletes return over several weeks to months with a structured rehab program. A gradual throwing progression is key.

Find a Sports Medicine Provider

Connect with a doctor, physical therapist, or imaging center near you.

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