In order to investigate the isokinetic strength of the thigh muscles at different knee flexion angles in patients 12 months after anterior cruciate ligament (ACL) reconstruction, an open-chain concentric and eccentric tests of the quadriceps and hamstring were performed at an angular velocity of 60°/s in 16 males 12 months after ACL reconstruction and 14 healthy controls. The peak muscle strength of different contraction patterns at different knee flexion angles were analyzed and the following ratios were calculated: the concentric ratio of hamstring to quadriceps (Hc/Qc), the eccentric ratio of hamstring to quadriceps (He/Qe), the eccentric ratio of hamstring to the concentric ratio of quadriceps (He/Qc), and the concentric ratio of hamstring to the eccentric ratio of quadriceps (Hc/Qe). A two-way ANOVA with mixed design was used to examine the effects of groups and legs on isokinetic muscle strength characteristics. The following results can be concluded. The hamstring strength characteristics were similar at different knee flexion angles, with the reconstructed leg being significantly smaller than the contralateral leg and not different from the healthy controls. In contrast, the isokinetic quadriceps strength showed angle specificity, and the concentric quadriceps strength of the reconstructed leg at 40° and 50° of knee flexion differed not only from the contralateral leg but also from the healthy control leg, making it a more specific index for assessing muscle strength characteristics. Attention should be paid not only to bilateral symmetry but also to whether it is restored to the level of healthy individuals, emphasizing the recovery of muscle function at specific angles in rehabilitation. The flexion-extension strength ratios of bilateral lower limbs at smaller flexion angles differed from those of healthy controls, suggesting that postoperative rehabilitation should strengthen the control training of knee flexion movements of the reconstructed leg and improve the cushioning control ability of the contralateral leg. 

为了分析前交叉韧带(ACL)重建术后12个月患者的大腿肌肉在不同屈膝角度时的等速肌力特征, 对16名ACL重建术后12个月的患者和 14名健康对照者在60°/s 的角速度下进行股四头肌和腘绳肌的等速向心和离心开链肌力测试, 分析不同等速收缩模式下的肌力峰值及不同屈膝角度时的肌力, 并计算腘绳肌与股四头肌等速向心肌力比值(Hc/Qc)离心肌力比值(He/Qe)、腘绳肌离心与股四头肌向心肌力比值(He/Qc)和腘绳肌向心肌力与股四头肌离心肌力比值(Hc/Qe)。应用混合设计双因素方差分析方法, 检验不同人群和不同侧别对大腿等速肌力特征的影响。结果表明, 腘绳肌等速肌力在不同屈膝角度时的特征相似, ACL 重建侧显著小于对侧, 与健康对照者无显著差异。股四头肌等速肌力呈现角度特异性, 屈膝40°和50°时重建侧的股四头肌等速向心肌力不仅与对侧存在差异, 也与健康人群不同, 是更具特异性的评估肌力特征指标。在康复过程中, 不仅要关注双侧对称性, 而且要关注其是否恢复到健康者的水平, 强调特定角度下肌肉功能的恢复。较小屈膝角度下, 双侧下肢的功能性屈伸肌力比值与健康人群均呈现差异, 提示术后康复不仅要加强重建侧屈膝动作的控制训练, 也要同时改善对侧的缓冲控制能力。