Abstract
BACKGROUND: Conventional hamstring-to-quadriceps (H:Q) ratios may not adequately reflect functional muscle balance during high-speed movements. As a more functionally relevant parameter, the dynamic control ratio at the equilibrium point (DCR(e)), which identifies the specific joint angle where eccentric hamstring torque counterbalances concentric quadriceps torque, has been proposed; however, its relationship with performance variables remains unclear. Therefore, this study aimed to investigate the effect of DCR(e), as well as conventional (H(c):Q(c)) and functional (H(e):Q(c)) hamstring-to-quadriceps ratios, on acceleration and deceleration performance in athletes. METHODS: This cross-sectional study included forty team sport athletes (age: 22.00 ± 2.90 years; body weight: 76.52 ± 11.77 kg; height: 178.12 ± 6.02 cm; training age: 11.15 ± 2.72 years). Eccentric and concentric isokinetic strength tests were performed in the seated position at angular velocities of 30°/s, 90°/s, and 150°/s. Strength data were filtered using an Equiripple low-pass filter with a 6 Hz cut-off frequency and DCR(e) angle and torque values were identified through a coding method in MATLAB. Acceleration was assessed using a 10-meter sprint test, while deceleration was evaluated based on stopping distance and time. The effects of strength variables on performance were analyzed using linear regression, and no multicollinearity was observed (VIF < 10, Tolerance > 0.10). RESULTS: DCR(e) angle values were found to be 27.7°, 26.2°, and 26.4°, and torque values were 1.74, 1.76, and 1.73 N·m/kg at 30°/s, 90°/s, and 150°/s, respectively. DCR(e) parameters and H(c):Q(c) and H(e):Q(c) ratios did not significantly affect acceleration (p > 0.05). However, H(c):Q(c) at 90°/s and 150°/s, and H(e):Q(c) at 150°/s significantly affected deceleration time (p < 0.05). CONCLUSION: Although DCR(e) parameters did not directly influence acceleration or deceleration performance, the influence of hamstring-to-quadriceps strength ratios at higher speeds suggests that eccentric-based neuromuscular control may play a critical role in braking actions. Further studies involving elite team sport athletes are needed to better understand the potential role of DCR(e) in athletic performance. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13102-026-01552-9.