Author(s): WATANABE, Y., SANO, Y., HIRAYAMA, K., MURASE, M., KAWABATA, M., WATANABE, H., TAKAHIRA, N., Institution: KITASATO UNIVERCITY GRADUATE SCHOOL, Country: JAPAN, Abstract-ID: 2626

INTRODUCTION:
Non-contact anterior cruciate ligament (ACL) injuries are associated with dynamic knee valgus during jump tasks such as Drop Vertical Jump (DVJ). While the hamstrings play a crucial role in the dynamic stability of the knee joint, their assessment often does not adequately reflect the high-speed, coordinated capabilities required in actual sports movements. The Maximum-Speed Single-Leg Bridge Test (MS-SLBT) is a novel test for assessing the ability for fast, repetitive hip extension.1) This study aimed to clarify the relationship between the MS-SLBT metrics and knee kinematic parameters associated with ACL injury risk during the Singe-Leg DVJ (SL-DVJ).
METHODS:
22 healthy male athletes (age: 21.0±1.5 years, height: 171±5.2 cm, mass: 64.5±6.1 kg) performed SL-DVJ from a 15 cm box and MS-SLBT on their dominant leg. MS-SLBT involves lying in a supine position, placing the heel on a 40 cm box, and raising the buttocks as fast and as high as possible for twenty repetitions.1) MS-SLBT metrics included peak buttock-raising height and speed, with mean values calculated for repetitions 2 to 19. SL-DVJ kinematics were measured using a 3D motion analysis system, calculating knee flexion/abduction and hip flexion angles at initial contact (IC), as well as peak knee flexion/abduction/internal rotation angles, peak hip flexion angle, and peak knee abduction/internal rotation moments within 0–50 ms post-IC. Spearman's rank correlation coefficient was used to assess the correlation between the MS-SLBT and the SL-DVJ metrics. The magnitude of the correlations was interpreted using Cohen's criteria as small (ρ ≥ 0.10), medium (ρ ≥ 0.30), and large (ρ ≥ 0.50).
RESULTS:
The buttock-raising height during the MS-SLBT showed a significant negative correlation of medium magnitude with peak knee abduction angle (ρ = −0.42, p < 0.05) and peak knee internal rotation angle (ρ = −0.42, p < 0.05) within 0-50 ms post-IC during the SL-DVJ. No significant correlations were found with any angles at IC or with other kinematic/kinetic variables at 0–50 ms. Furthermore, no buttock-raising speed metrics from any phase showed a significant correlation with any SL-DVJ metrics.
CONCLUSION:
This study showed that buttock-raising height in the MS-SLBT was associated with reduced knee abduction and internal rotation during the SL-DVJ. This suggests that the MS-SLBT buttock-raising height is involved in the dynamic control of the knee joint in the frontal and horizontal planes during landing.
REFERENCE:
1) Sano Y, Kawabata M, Van Hooren B, Sumiya Y, Murase M, Watanabe Y, Shimono Y, Kenmoku T, Watanabe H, Takahira N. A practical assessment of hamstring muscle endurance and fatigue using the maximum-speed single-leg bridge test. BMC Sports Sci Med Rehabil. 2025 Dec 5;18(1):18.