Comparison Of Warm-Up Strategies On Internal And External Rotation Mechanics In Collegiate Pitchers

Abstract

Rotator cuff strains are the most common musculoskeletal injury in collegiate baseball pitchers. A variety of warm-up routines are employed, the effects of these routines on the subsequent function of the rotator cuff lack comparison. PURPOSE: To test the effect of four different warm-up routines on internal (IR) and external rotation (ER) shoulder kinematics. METHODS: Seven D1 collegiate pitchers were enrolled in an experiment involving four testing sessions. Each session began with one of four warm-up protocols: 1) Jaeger bands (JB), 2) standard dynamic warm-up (DW), 3) Jaeger bands and standard dynamic warm-up (JBDW), or 4) dynamic warm-up using collinear resistance (CR). Immediately after the warm-up, athletes underwent biomechanical analysis of internal and external shoulder rotation using Proteus (Proteus Motion, USA). They performed 12 repetitions of each motion using 5lb of 3D magnetic resistance. 48 hours of rest separated each session. The assigned sequence of protocols was counter-balanced. Proteus software computed peak power in watts (w), peak force development rate in watts/second, range of motion in meters (ROM), consistency (the ability to replicate ROM in three-dimensional space), and endurance (replication of power parameters in successive repetitions). A one-way repeated measures ANOVA was used. RESULTS: Subjects were 20.4±1.4 years of age. Across all conditions, peak power was 96.3±13.7 w in IR and 99.3±15.7 w in ER; peak force development rate was 387.7±118.5 w/sec in IR, and 418.7±195.6 w/sec in ER. Differences were detected in the four warm-up conditions in peak power (CR highest; p=0.015), peak force development rate (CR highest; p=0.072), and ROM (CR highest; p=0.015). No difference was found in deceleration (p=0.336), consistency (p=0.903), or endurance (p=0.769). External rotation was different in the four warm-up conditions in peak force development rate (CR highest; p=0.045). No statistical difference was found in power (CR was highest, but did not reach significance; p=0.104), deceleration (p=0.520), consistency (p=0.478), endurance (p=0.145), or ROM (p=0.543). CONCLUSION: The simulated dynamic warm-up using three-dimensional resistance elicited the best subsequent function, follow up studies should examine mechanisms that produce this difference.