發力率訓練與去抑制介入對股四頭肌發力率、關節性肌肉自主抑制與前十字韌帶生物力學風險因子之影響

Background: Arthrogenic muscle inhibition (AMI) following anterior cruciate ligament reconstruction (ACLR) adversely affects quadriceps muscle function. The goal to diminish AMI and enhance quadriceps rapid contraction is important in optimizing post-ACLR rehabilitation effectiveness and safety return to play. However, no studies investigated the association between explosive quadriceps strength deficits and AMI following ACLR. No studies investigated the immediate and subsequent impacts from de-inhibitory intervention on explosive quadriceps strength and AMI though cryotherapy had been effectively resolved neuromuscular inhibition. Objective: The aim of the first-year project is to determine the association between explosive quadricep strength (quantified by rate of torque development (RTD) and AMI (quantified by central activation ratio (CAR) before intervention, and investigate the impact of disinhibitory intervention on explosive quadriceps strength and AMI, and duration of effects. Methods: 40 female ACLR participants had been randomized into either the control or intervention group. RTD and CAR were measured separately before intervention and immediately, at 30- and 60-minutes post-intervention. Results: The correlation coefficients (ρ) between absolute and normalized RTD and CAR were .33 (p = .03) and -.28 (p = .07), respectively. The main effects of time reached statistical significance (p = .002) in absolute RTD. Nevertheless, absolute RTD was increased before intervention than 60-minutes post-intervention despite no differences between prior-intervention and immediate post-intervention (p > .05). No statistical significance in main effects and interaction in normalized RTD (p > .05). Conclusion: ACLR females with higher quadriceps neuromuscular function deficits had decreased RTD. Disinhibitory intervention of cryotherapy failed to resolve neuromuscular function deficits and RTD immediately. Future studies should explore structural components related to RTD to comprehensively understand the potential mechanisms contributing to impaired RTD in this population. Objective: The aim of the second-year project is to determine the effects of explosive quadriceps strength and disinhibitory intervention on quadriceps function and landing biomechanics in ACLR females. Methods: 28 female ACLR participants had been randomized into either the control, training, and intervention group in 8-week RTD training. Quadriceps function and either double- or single-legged landing biomechanics were measured prior to and after intervention. Results: The main effects and interaction almost failed to reach statistical significance in quadriceps function except of the time effect in CAR (p = .01, η2p = .23). Absolute RTD predicted 13% single-legged sagittal-plane knee angle (p = .04) and 15% time to peak posterior ground reaction force (pGRF) (p = .03) as well as 16% prediction in the group*normalized RTD interaction. The group effect predicted 12% anterior tibial shear force (ATSF) (p = .04). The interaction predicted 12%~30% posterior ground reaction force (p = .04–.002). Conclusion: RTD training and disinhibitory intervention led to partial improvement in neural drive except of overall quadriceps mechanical output in ACLR females. Favorable RTD positively affected knee flexion control and delayed the time to peak ground impact in single-legged tasks, and explained the comparison between ATSF and pGRF in double-legged tasks yet. The findings indicated a closed association between RTD and the ability to absorb impact and manage load during landing.