Isokinetic profile of elbow flexion and extension strength in elite junior tennis players

Study Design: Descriptive study. Objectives: To determine whether bilateral differences exist in concentric elbow flexion and extension strength in elite junior tennis players. Background: The repetitive nature of tennis frequently produces upper extremity overuse injuries. Prior research has identified tennis-specific strength adaptation in the dominant shoulder and distal upper extremity musculature of elite players. No previous study has addressed elbow flexion and extension strength. Methods and Materials: Thirty-eight elite junior tennis players were bilaterally tested for concentric elbow flexion and extension muscle performance on a Cybex 6000 isokinetic dynamometer at 90degrees/s, 210degrees/s, and 300degrees/s. Repeated-measures ANOVAs were used to test for differences between extremities, muscle groups, and speed. Results: Significantly greater (P<0.002) dominant-arm elbow extension peak torque values were measured at 90 degrees/s, 210 degrees/s, and 300 degrees/s for males. Significantly greater (P<0.002) dominant-arm single-repetition work values were also measured at 90degrees/s and 210degrees/s for males. No significant difference was measured between extremities in elbow flexion muscular performance in males and for elbow flexion or extension peak torque and single-repetition work values in females. No significant difference between extremities was measured in elbow flexion/extension strength ratios in females and significant differences between extremities in this ratio were only present at 210degrees/s in males (P<0.002). Conclusion: These data indicate muscular adaptations around the dominant elbow in male elite junior tennis players but not females. These data have ramifications for clinicians rehabilitating upper extremity injuries in patients from this population.