Background Optimal strength plays a pivotal role in reducing the risk of sports-related injuries; nonetheless, the unique characteristics of strength warrant specific and focused assessment.

Objective to evaluate the association between peak torque and the rate of force development (RFD) in a cohort of elite level athletes

Design cross-sectional study Setting data obtained from athletes training at Institut National du Sport du Québec

Participants 183 healthy athletes partaking in national or international level sport competitions (73 males and 104 females)

Assessment of Risk Factors evaluation of torque strength using a Con-TREX MJ system at 60°/s for knee joint muscles and 180°/s for shoulder joint muscles

Main Outcome Measurements Spearman rank correlations were employed to compare average peak torque and rates of force development in knee flexion and extension for lower-body sports, as well as shoulder internal and external rotation for upper-body sports. Furthermore, potential sex differences were assessed using Student t-tests.

Results Correlation analyses showed high to very high correlation between mean peak torque and RFD for the knee (rho=0.89 to 0.97) and for the shoulder (rho=0.83 to 0.99). Overall, the male athletes exhibited greater values of shoulder torque and RFD than the female athletes (p<0.01). Males were stronger in knee flexion as well, but group differences were not significant for knee extension torque (p=0.08) or RFD (p=0.29). Further analysis of the residuals indicate that outliers strayed further from the mean below the group average (IQR>1.5).

Conclusions Mean peak torque and RFD were highly correlated in this cohort of athletes. However, sizeable outliers were present when below-average RFD was present for athletes with typical peak torque. Further research is necessary to explore whether these characteristics are observed in injured athletes, and whether insufficient RFD values may be a better indicator of readiness to return to sport than peak torque.