School of Kinesiology, University of Michigan, Ann Arbor, Michigan.
Orthopedic Rehabilitation and Biomechanics (ORB) Laboratory, University of Michigan, Ann Arbor, Michigan.
Sports Health. 2024 Sep-Oct;16(5):808-816. doi: 10.1177/19417381231205295. Epub 2023 Oct 24.
Quadriceps neuromuscular function is negatively affected after anterior cruciate ligament reconstruction (ACLR). The specific effect that the ACLR has on the quadriceps femoris rate of force production and its impact on functional recovery is unknown.
The anterior cruciate ligament (ACL) limb would present persistent deficits in the rate of torque development (RTD), when compared with the non-ACL limb before ACLR until 9 months (9M) post-ACLR.
Prospective cohort study.
Level 3.
Twenty-eight participants performed quadriceps maximum voluntary isometric contractions (MVICs) before (PRE), at 5 months (5M) and at 9M after ACLR. Single-leg hop distance was also assessed at 9M. Quadriceps RTD was calculated at 50, 100, and 200 ms after the onset of torque production. Maximum RTD was also calculated. A 2 (limb) × 3 (time) repeated-measures analysis of variance was used for RTD, RTD, RTD, and RTD. Linear regressions were used to evaluate the associations of MVIC and RTD values at 5M and 9M with single-leg hop distance at 9M.
The ACL limb had lower RTD values at all times compared with the non-ACL limb ( < 0.05). RTD of the ACL limb significantly decreased from PRE to 5M, and then recovered to PRE levels at 9M ( < 0.05). The non-ACL limb displayed no differences from baseline to either 5M or 9M. MVIC and RTD at 5M predicted ( = 0.313 and = 0.262, respectively) single-leg hop distance at 9M, better than the strength and RTD at 9M ( = 0.235 and = 0.128, respectively).
Quadriceps RTD is negatively affected after ACLR, and deficits may persist at the time of return to activity. Strength and RTD during recovery at 5M may predict more than 25% of the variance in single-leg hop distance at 9M, independently; hence, both provide important information to monitor functional recovery post-ACLR.
RTD should be measured to understand the changes in neuromuscular capacity after ACLR, and rehabilitation strategies that target quick force production, ie, quick muscle activation and functional tasks, should be implemented.
前交叉韧带重建（ACL）后，股四头肌神经肌肉功能受到负面影响。ACL 重建对股四头肌力量产生的速率以及对功能恢复的具体影响尚不清楚。
与 ACL 重建前相比，ACL 侧在 ACL 重建后 5 个月（5M）和 9 个月（9M）时，扭矩发展速率（RTD）仍存在持续缺陷。
前瞻性队列研究。
3 级。
28 名参与者在 ACL 重建前（PRE）、5 个月（5M）和 9 个月（9M）时进行股四头肌最大等长收缩（MVIC），并在 9M 时评估单腿跳距离。在扭矩产生后 50、100 和 200ms 时计算股四头肌 RTD。还计算了最大 RTD。采用 2（肢体）×3（时间）重复测量方差分析比较 RTD、RTD、RTD 和 RTD。线性回归用于评估 5M 和 9M 时 MVIC 和 RTD 值与 9M 时单腿跳距离的相关性。
与非 ACL 侧相比，ACL 侧在所有时间点的 RTD 值均较低（<0.05）。从 PRE 到 5M，ACL 侧的 RTD 显著下降，然后在 9M 时恢复到 PRE 水平（<0.05）。非 ACL 侧从基线到 5M 或 9M 均无差异。5M 时的 MVIC 和 RTD 预测了 9M 时单腿跳距离（=0.313 和=0.262），优于 9M 时的力量和 RTD（=0.235 和=0.128）。
ACL 重建后股四头肌 RTD 受到负面影响，活动恢复时可能仍存在缺陷。恢复时 5M 时的力量和 RTD 可能分别独立预测 9M 时单腿跳距离的 25%以上的变异性，因此两者都为监测 ACL 重建后的功能恢复提供了重要信息。
应测量 RTD 以了解 ACL 重建后神经肌肉能力的变化，并应实施针对快速力量产生的康复策略，即快速肌肉激活和功能任务。
