Lower-extremity isokinetic strength ratios of elite springboard and platform diving athletes

Objectives: The purpose of the present study was to examine knee extensor and flexor muscle strength ratios of an elite group of diving athletes. Methods: Sixteen divers (10 females and 6 males) from the Brazil national team were assessed for lower-body strength. They had participated in international competitions such as the 2016 Olympic Games and 2015 Pan American Games. The dynamic concentric torque of their knee flexor and extensor muscles were evaluated using a Biodex isokinetic dynamometer. Bilateral tests were performed at 60 degrees s(-1). Flexor to extensor (F/E) peak torque ratio and percentage bilateral difference (BD%) was also measured. Results: The results revealed that elite diving athletes produced higher than usual reported in previous studies for relative knee extension torque (3.2 for females and 3.6 for males N.m.kg(-1)). However, they presented low levels of knee flexor torque (1.5 for females and 1.8 for males N.m.kg(-1)). These results are reflected in a low F/E ratio (0.39 to 0.49). Males presented a greater BD% in knee flexors when compared to females (12.4% vs 6.6%). Conclusion: Elite diving athletes demonstrated high knee extensor and low knee flexor strength. This partially explains their low F/E ratio, which might increase risk of knee injuries. Strength and conditioning programs should strive to correct knee strength imbalances in diving athletes where necessary.