[en] javelin throwers ; isokinetic ; shoulder ; field performance
[en] Published data related to javelin throwers remain poorly documented. The objectives of this study were therefore to compare isokinetic strength profile of the shoulder rotator muscles between javelin throwers and sedentary persons and to correlate isokinetic data with different field performance parameters. Eleven male javelin throwers and ten sedentary subjects participated in the study. Shoulder internal (IRs) and external rotators (ERs) were isokinetically assessed at 60, 240 and 400 degrees/s in concentric and 60 degrees/s in eccentric exertions. Subjects also performed throwing tests successively using a javelin and a ball (both of 800 g mass). Side to side comparison in the throwers group revealed a dominance effect in the concentric mode for the IRs at all speeds, and for the ERs at 240 degrees/s. Sedentary subjects showed a dominance effect for the IRs at 60 degrees/s and 240 degrees/s. Simple isokinetic concentric-concentric ratios and mixed velocity DCRs (eccentric60/concentric240) of the dominant shoulder were significantly lower in comparison to the non-dominant side values, in the throwers population. Only the simple ratio at 400 degrees/s and the mixed ratio were significantly lower in the sedentary subjects (dominant versus non dominant side). With respect to the dominant shoulder, no significant difference was noted between the groups the peak torque was bodyweight normalized. However, throwers showed a significant reduction of the DCR when compared to the control group. In addition, throwers exhibited moderate to strong correlations (0.61 <= r <= 0.89) between IRs and ERs strength and either the javelin throw test or the personal throwing record. For the sedentary subjects the javelin throw test was correlated only with the IRs concentric strength at 240 degrees/s. In conclusion, javelin throwers showed a significantly reduced mixed ratio in comparison with a control group, even though body weight normalized peak torques did not differ between both populations. Significant correlation was established between rotator peak-torques and javelin throw test among the thrower athletes. Although training program in thrower athletes classically focuses on IRs strengthening, our findings strongly suggest the need for ERs performance improvement.