This study compared lower-limb muscle function, defined as the contributions of muscles to center-of-mass support and braking, during a single-leg hopping task in anterior cruciate ligament-reconstructed (ACLR) individuals and uninjured controls. In total, 65 ACLR individuals and 32 controls underwent a standardized anticipated single-leg forward hop. Kinematics and ground reaction force data were input into musculoskeletal models to calculate muscle forces and to quantify muscle function by decomposing the vertical (support) and fore-aft (braking) ground reaction force components into contributions by individual lower-limb muscles. Four major muscles, the vasti, soleus, gluteus medius, and gluteus maximus, were primarily involved in support and braking in both ACLR and uninjured groups. However, although the ACLR group demonstrated lower peak forces for these muscles (all Ps < .001, except gluteus maximus, P = .767), magnitude differences in these muscles’ contributions to support and braking were not significant. ACLR individuals demonstrated higher erector spinae (P = .012) and hamstrings forces (P = .085) to maintain a straighter, stiffer landing posture with more forward lumbar flexion. This altered landing posture may have enabled the ACLR group to achieve similar muscle function to controls, despite muscle force deficits. Our findings may benefit rehabilitation and the development of interventions to enable faster and safer return to sport.

这项研究比较了前十字韧带重建 (ACLR) 个体和未受伤对照者在单腿跳跃任务中的下肢肌肉功能，定义为肌肉对质心支撑和制动的贡献。总共有 65 名 ACLR 个体和 32 名对照组接受了标准化预期单腿向前跳跃。将运动学和地面反作用力数据输入到肌肉骨骼模型中，以计算肌肉力，并通过将垂直（支撑）和前后（制动）地面反作用力分量分解为各个下肢肌肉的贡献来量化肌肉功能。在 ACLR 组和未受伤组中，四种主要肌肉，股肌、比目鱼肌、臀中肌和臀大肌主要参与支撑和制动。然而，尽管 ACLR 组表现出这些肌肉的峰值力较低（所有P s < .001，臀大肌除外，P  = .767），但这些肌肉对支撑和制动的贡献的大小差异并不显着。ACLR 个体表现出更高的竖脊肌 ( P  = .012) 和腿筋力量 ( P  = .085)，以保持更直、更僵硬的着陆姿势以及更多的腰椎前屈。这种改变的着陆姿势可能使 ACLR 组能够实现与对照组相似的肌肉功能，尽管肌力存在缺陷。我们的研究结果可能有利于康复和干预措施的开发，以便更快、更安全地重返运动。