He Xin, Qiu Jihong, Cao Mingde, Ho Yui Chung, Leong Hio Teng, Fu Sai-Chuen, Ong Michael Tim-Yun, Fong Daniel T P, Yung Patrick Shu-Hang
Department of Orthopaedics & Traumatology, Faculty of Medicine, The Chinese University of Hong Kong, Hong Kong, China.
National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.
Orthop J Sports Med. 2022 Jan 4;10(1):23259671211063893. doi: 10.1177/23259671211063893. eCollection 2022 Jan.
Understanding the role of neuromuscular and mechanical muscle properties in knee functional performance and dynamic knee stability after anterior cruciate ligament reconstruction (ACLR) may help in the development of more focused rehabilitation programs.
To compare the involved and uninvolved limbs of patients after ACLR in terms of muscle strength, passive muscle stiffness, muscle activation of the quadriceps and hamstrings, hop performance, and dynamic knee stability and to investigate the association of neuromuscular and mechanical muscle properties with hop performance and dynamic knee stability.
Cross-sectional study; Level of evidence, 3.
The authors studied the quadriceps and hamstring muscles in 30 male patients (mean ± SD age, 25.4 ± 4.1 years) who had undergone unilateral ACLR. Muscle strength was measured using isokinetic testing at 60 and 180 deg/s. Passive muscle stiffness was quantified using ultrasound shear wave elastography. Muscle activation was evaluated via electromyographic (EMG) activity. Hop performance was evaluated via a single-leg hop test, and dynamic knee stability was evaluated via 3-dimensional knee movements during the landing phase of the hop test.
Compared with the uninvolved limb, the involved limb exhibited decreased peak torque and shear modulus in both the quadriceps and hamstrings as well as delayed activity onset in the quadriceps ( < .05 for all). The involved limb also exhibited a shorter hop distance and decreased peak knee flexion angle during landing ( < .05 for both). Decreased peak quadriceps torque at 180 deg/s, the shear modulus of the semitendinosus, and the reactive EMG activity amplitude of the semimembranosus were all associated with shorter hop distance ( = 0.565; < .001). Decreased quadriceps peak torque at 60 deg/s and shear modulus of the vastus medialis were both associated with smaller peak knee flexion angle ( = 0.319; < .001).
In addition to muscle strength deficits, deficits in passive muscle stiffness and muscle activation of the quadriceps and hamstrings were important contributors to poor single-leg hop performance and dynamic knee stability during landing. Further investigations should include a rehabilitation program that normalizes muscle stiffness and activation patterns during landing, thus improving knee functional performance and dynamic knee stability.
了解神经肌肉和肌肉力学特性在前交叉韧带重建（ACLR）后膝关节功能表现和动态膝关节稳定性中的作用，可能有助于制定更有针对性的康复计划。
比较ACLR术后患者患侧和健侧肢体在肌肉力量、被动肌肉僵硬度、股四头肌和腘绳肌的肌肉激活、单腿跳性能以及动态膝关节稳定性方面的差异，并研究神经肌肉和肌肉力学特性与单腿跳性能和动态膝关节稳定性之间的关联。
横断面研究；证据等级，3级。
作者研究了30例接受单侧ACLR的男性患者（平均年龄±标准差，25.4±4.1岁）的股四头肌和腘绳肌。使用等速测试在60和180°/s下测量肌肉力量。使用超声剪切波弹性成像技术量化被动肌肉僵硬度。通过肌电图（EMG）活动评估肌肉激活情况。通过单腿跳测试评估单腿跳性能，并在单腿跳测试的落地阶段通过三维膝关节运动评估动态膝关节稳定性。
与健侧肢体相比，患侧肢体的股四头肌和腘绳肌的峰值扭矩和剪切模量均降低，股四头肌的活动起始延迟（所有P<0.05）。患侧肢体的单腿跳距离也较短，落地时的膝关节最大屈曲角度减小（两者P<0.05）。180°/s时股四头肌峰值扭矩降低、半腱肌的剪切模量降低以及半膜肌的反应性EMG活动幅度降低均与单腿跳距离较短相关（r = 0.565；P<0.001）。60°/s时股四头肌峰值扭矩降低和股内侧肌的剪切模量降低均与膝关节最大屈曲角度较小相关（r = 0.319；P<0.001）。
除了肌肉力量不足外，被动肌肉僵硬度以及股四头肌和腘绳肌的肌肉激活不足是导致单腿跳性能差和落地时动态膝关节稳定性差的重要因素。进一步的研究应包括一个康复计划，使落地时的肌肉僵硬度和激活模式正常化，从而改善膝关节功能表现和动态膝关节稳定性。
