Cobian Daniel G, Oppenheim Zachary R, Roehl Tyler J, Joachim Mikel R, Heiderscheit Bryan C
Orthopedics and Rehabilitation, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Badger Athletic Performance Program, University of Wisconsin-Madison, Madison, Wisconsin, USA.
Orthop J Sports Med. 2024 Jun 11;12(6):23259671241253843. doi: 10.1177/23259671241253843. eCollection 2024 Jun.
Quadriceps performance after anterior cruciate ligament reconstruction (ACLR) is typically characterized by peak force/torque, but the ability to generate consistent knee extensor torque may be clinically meaningful.
PURPOSE/HYPOTHESIS: The purpose of this study was to evaluate knee extensor torque steadiness and quadriceps activation variability in collegiate athletes 4 to 12 months after ACLR. It was hypothesized that between-limb asymmetries in torque steadiness and activation variability would be observed and that steadiness would be associated with activation variability and peak knee extensor torque symmetry.
Case-control study; Level of evidence, 3.
A total of 30 National Collegiate Athletic Association Division I athletes completed maximal voluntary isometric contractions 4, 6, and 12 months after ACLR. Torque and surface electromyography of the superficial quadriceps were recorded. Torque steadiness was calculated as the mean difference between initial and low-pass filtered torque signals and was expressed as a percentage of peak torque. Quadriceps activation variability was calculated similarly and was expressed as a percentage of peak electromyography. Linear mixed models were used to assess change in torque steadiness and activation variability over time. Associations between torque steadiness of the operated limb, activation variability, and quadriceps strength symmetry were evaluated using the Spearman correlation coefficient.
Limb-by-time interactions were detected for torque steadiness and activation variability ( < .001), with reductions (improvements) in limb steadiness and activation variability observed with increasing time since surgery. Between-limb differences in torque steadiness and activation variability were observed at 4 and 6 months postoperatively ( < .05). Significant associations between operated limb torque steadiness and quadriceps activation variability were observed at 4 months ( < .001) and 6 months ( < .01). Torque steadiness of the operated limb was associated with peak knee extensor torque symmetry at 4 months ( = -0.49; < .01) and 6 months ( = -0.49; < .01).
In collegiate athletes, impaired knee extensor torque steadiness of the operated limb and associated abnormal quadriceps activation patterns were observed 4 to 12 months after ACLR, and the consistency of knee extensor torque production was associated with greater quadriceps strength asymmetries, particularly 4 to 6 months after surgery. Operated limb torque steadiness and activation variability improved from 4 to 12 months after ACLR. Clinical assessment of knee extensor torque steadiness after ACLR may improve prognosis and specificity of rehabilitation efforts.
前交叉韧带重建（ACLR）后股四头肌的表现通常以峰值力/扭矩为特征，但产生持续膝关节伸展扭矩的能力可能具有临床意义。
目的/假设：本研究的目的是评估ACLR后4至12个月的大学生运动员的膝关节伸展扭矩稳定性和股四头肌激活变异性。假设在扭矩稳定性和激活变异性方面会观察到肢体间不对称，并且稳定性将与激活变异性和膝关节伸展峰值扭矩对称性相关。
病例对照研究；证据等级，3级。
共有30名美国国家大学体育协会第一分区的运动员在ACLR后4、6和12个月完成了最大自主等长收缩。记录了股四头肌浅层的扭矩和表面肌电图。扭矩稳定性计算为初始扭矩信号与低通滤波扭矩信号之间的平均差异，并表示为峰值扭矩的百分比。股四头肌激活变异性的计算方法类似，并表示为峰值肌电图的百分比。使用线性混合模型评估扭矩稳定性和激活变异性随时间的变化。使用Spearman相关系数评估患侧肢体的扭矩稳定性、激活变异性和股四头肌力量对称性之间的关联。
在扭矩稳定性和激活变异性方面检测到肢体与时间的交互作用（P<0.001），随着术后时间的增加，观察到肢体稳定性和激活变异性降低（改善）。术后4个月和6个月观察到扭矩稳定性和激活变异性的肢体间差异（P<0.05）。在术后4个月（P<0.001）和6个月（P<0.01）观察到患侧肢体扭矩稳定性与股四头肌激活变异性之间存在显著关联。患侧肢体的扭矩稳定性在术后4个月（r=-0.49；P<0.01）和6个月（r=-0.49；P<0.01）与膝关节伸展峰值扭矩对称性相关。
在大学生运动员中，ACLR后4至12个月观察到患侧肢体膝关节伸展扭矩稳定性受损以及相关的股四头肌激活模式异常，并且膝关节伸展扭矩产生的一致性与更大的股四头肌力量不对称相关，特别是在术后4至6个月。ACLR后4至12个月，患侧肢体扭矩稳定性和激活变异性有所改善。ACLR后对膝关节伸展扭矩稳定性的临床评估可能会改善康复效果的预后和特异性。
