The Effect of In-Game Cervical Exercises on Shoulder Internal Rotation Range of Motion and External Rotator Strength in Baseball Pitchers.

Background: Consensus is lacking regarding the underlying cause of two prevalent risk factors for shoulder and elbow pain in overhead throwing athletes: loss of shoulder internal rotation (IR) range of motion (ROM) and strength of the external rotators (ER). Consideration of cervical spine contribution may have important implications for rehabilitation and coaching of overhead throwers. Purpose: The purpose of this study was to investigate the effect of performing active cervical retraction and retraction with extension exercises between innings of pitching a simulated game on shoulder IR ROM and ER strength following completion of the game. Study Design: Randomized controlled study. Methods: Passive shoulder IR ROM at 90° of abduction and ER strength at 0° of abduction were assessed in healthy male baseball pitchers. Participants were randomized to a control or experimental group and completed a simulated game totaling 60 pitches. Those in the experimental group performed 10 repetitions of active cervical retraction and retraction with extension exercises with a 3-second hold at end-range between innings, while those in the control group rested. Shoulder IR ROM and ER strength were re-assessed immediately following the simulated game. Independent samples t-test was used to assess for between-group differences and effect sizes were calculated using Cohen's d. Results: Twenty pitchers (mean age=19.2 ± 3.3) completed the study. All 10 pitchers in the experimental group demonstrated an increase in shoulder IR ROM (mean gain 7.7° ± 4.9) while all 10 pitchers in the control group demonstrated a loss of ROM (mean loss 8.4° ± 5.3), resulting in a significant between-group difference of 16.1° (p<0.001). Though the experimental group demonstrated a mean ER strength loss of 0.5kg compared to a 1.0kg loss in the control group, this difference was not statistically significant (p=0.399). Conclusion: Active cervical retraction and retraction with extension exercises performed between innings during a simulated game resulted in increased shoulder IR ROM compared to controls. Although ER strength loss was attenuated in the experimental group, this finding did not reach significance and is worthy of further exploration. Level of Evidence: Level 2.