056 - The Catch-Up Cost: How Shoulder Injuries Rewrite the Thrower’s Kinetic Chain
The Question:
Does a prior shoulder injury alter the kinetic chain (KC) during overhead throwing — and if so, how?
The Setup:
36 male overhead athletes
- 18 Asymptomatic (no shoulder injury history)
- 18 Symptomatic (history of shoulder instability/rotator cuff pathology)3D motion capture of maximal overhead throws
Focus: Timing and magnitude of joint angular velocities across key KC segments
What They Found:
⛓️ Kinetic Chain Sequence:
Overall sequence unchanged across groups — lower body to core to arm.
BUT: Timing at the shoulder changes in symptomatic throwers.
Asymptomatic: Shoulder flexion + elbow extension = simultaneous (both 0.17% before ball release)
Symptomatic: Elbow extension = 0.06% before BR, Shoulder flexion = 0.67% after BR
🔁 Compensation Patterns:
Symptomatic throwers had:
Lower angular velocities in:
Lead & rear hip internal rotation
Pelvic and thorax rotation
Higher pelvic forward tilt (inefficient energy transfer)
To maintain ball velocity, they ramped up:
Shoulder internal rotation velocity
Thorax flexion velocity
💣 Result:
Maintaining output with inefficient sequencing = increased distal load → higher injury risk
What This Means:
Autoregulation is not a gimmick; it’s a viable strategy for tactical athletes operating in dynamic, unpredictable training environments. Whether you're managing shift work, mission timelines, or recovery from injury, adapting load and volume in real-time can preserve gains, reduce injury risk, and match training to readiness.
But here’s the catch: Autoregulation only works when athletes have maturity, awareness, and honesty. For those with limited lifting experience or poor load awareness, autoregulation can easily become undertraining or overreaching.
Tactical Implications:
Strength Coaches:
Don’t just train the arm — restore hip & trunk rotation power.
Prioritize drills that re-synchronize elbow and shoulder timing (e.g., med ball wall throws, landmine presses).
Avoid overloading distal joints until proximal sequencing is reestablished.
Physical Therapists:
Monitor for “catch-up mechanics” (e.g., delayed shoulder flexion, excess thorax flexion).
Reinforce sequencing through:
Split stance cable rotations
Band-resisted shoulder flexion paired with elbow extension
Return-to-throw plans should include timing drills, not just strength thresholds.
🚨 5. THE WARNING LABEL
"Same velocity ≠ same movement strategy."
Throwers with prior injury often look normal on radar guns, but underneath, they’re overclocking the shoulder to compensate for lost power at the core. This “catch-up” strategy works… until it doesn’t.
Shoulder injuries don’t break the kinetic chain, they shift the workload distally, and the shoulder pays the price. Fix the engine (hip + trunk), not just the exhaust pipe (arm).
Owens LP, Coyles G, Khaiyat O. Alterations to the Kinetic Chain Sequence After a Shoulder Injury in Throwing Athletes. Orthop J Sports Med. 2024;12(11):23259671241288889. Published 2024 Nov 14. doi:10.1177/23259671241288889