Forearm muscle profiles in tennis players

Objective: To investigate the muscle strength profile of the forearm in experienced tennis players and non-tennis players, including establishment of reproducibility data for dynamometer testing of grip strength, forearm and wrist torque. Methods: Grip strength was evaluated using a mechanical handgrip dynamometer. Pronation/supination and wrist extension/flexion performance was tested using an isokinetic dynamometer. Ten subjects (mean age 22.9 +/- 1.8 yrs) took part in reproducibility testing. For the main study, twelve tennis players (mean age 24.6 +/- 9.3) and twelve controls (mean age 22.2 +/- 1.2) were evaluated using the same protocol. Results: Reproducibility values showed variability between testing sessions, highlighting that caution be employed when using this equipment. Average maximum grip strength of tennis players was significantly higher (p < 0.0001) in the dominant arm (51.19 kg) compared to their non-dominant arm (45.03 kg). Pronation in the dominant arm was significantly higher than the non-dominant arm in both subject groups. Wrist extension was stronger in the dominant arm compared to the non-dominant arm in both subject groups. Conclusion: Reproducibility of test protocol needs to be addressed if it is to be used in future comparative studies. This study indicates that prolonged asymmetrical sporting activity produces muscle profile asymmetries between and within limbs. The functional significance of these findings requires further investigation.