Evaluating the optimal height for hamstring activity in the maximum-speed single-leg bridge test

Hamstring strain injuries often occur during high-speed movements; yet, no functional test reliably induces rapid hamstring contractions. This study aimed to determine the optimal platform height in the maximum-speed single-leg bridge test to maximize hamstring activation. This cross-sectional study included 26 healthy male recreational athletes. Participants performed the maximum-speed single-leg bridge test using 20, 40, and 60 cm platforms at a maximal speed. The conventional single-leg bridge test was performed using a 60 cm platform at any speed. Measurements included buttock-raising speed; muscle activity of the semitendinosus, biceps femoris, and gluteus maximus using surface electromyography; and heel-bearing force. The maximum-speed single-leg bridge test showed significantly faster buttock-raising speeds (0.7-1.0 m/s) than the single-leg bridge test (0.5 m/s; p<0.01). Semitendinosus and biceps femoris muscle activities were significantly higher during the maximum-speed single-leg bridge test using 60 and 40 cm platforms (>90% maximal voluntary isometric contraction) than during the single-leg bridge test and the maximum-speed single-leg bridge test using a 20 cm platform (p<0.01). Gluteus maximus muscle activity during the maximum-speed single-leg bridge test was approximately double than that during the single-leg bridge test (p<0.01). The heel-bearing force was significantly higher during the maximum-speed single-leg bridge test than during the single-leg bridge test, and the maximum-speed single-leg bridge test using the 40 cm platform showed the highest force (p<0.01). The maximum-speed single-leg bridge test using 40 and 60 platforms required higher hamstring activity, with faster buttock-raising speeds and greater heel-bearing force than the single-leg bridge test and the maximum-speed single-leg bridge test using the 20 platform.