Department of Sports Medicine, Soonchunhyang University, Asan, South Korea.
School of Kinesiology and Orthopaedic and Rehabilitation Biomechanics Laboratory, University of Michigan, Ann Arbor.
J Athl Train. 2023 Feb 1;58(2):143-152. doi: 10.4085/1062-6050-74-21.
Although neuromuscular deficits in people with chronic ankle instability (CAI) have been identified, previous researchers have mostly investigated the activation of multiple muscles in isolation. Investigating muscle synergies in people with CAI would provide information about the coordination and control of neuromuscular activation strategies and could supply important information for understanding and rehabilitating neuromuscular deficits in this population.
To assess and compare muscle synergies using nonnegative matrix factorization in people with CAI and healthy control individuals as they performed different landing-cutting tasks.
Cross-sectional study.
Laboratory.
A total of 11 people with CAI (5 men, 6 women; age = 22 ± 3 years, height = 1.68 ± 0.11 m, mass = 69.0 ± 19.1 kg) and 11 people without CAI serving as a healthy control group (5 men, 6 women; age = 23 ± 4 years, height = 1.74 ± 0.11 m, mass = 66.8 ± 15.5 kg) participated.
MAIN OUTCOME MEASURE(S): Muscle synergies were extracted from electromyography of the lateral gastrocnemius, medial gastrocnemius, fibularis longus, soleus, and tibialis anterior (TA) muscles during anticipated and unanticipated landing-cutting tasks. The number of synergies, activation coefficients, and muscle-specific weighting coefficients were compared between groups and across tasks.
The number of muscle synergies was the same for each group and task. The CAI group exhibited greater TA weighting coefficients in synergy 1 than the control group (P = .02). In addition, both groups demonstrated greater fibularis longus (P = .03) weighting coefficients in synergy 2 during the unanticipated landing-cutting task than the anticipated landing-cutting task.
These results suggest that, although both groups used neuromuscular control strategies of similar complexity or dimensionality to perform the landing-cutting tasks, the CAI group displayed different muscle-specific weightings characterized by greater emphasis on TA function in synergy 1, which may reflect an effort to increase joint stability to compensate for ankle instability.
尽管人们已经发现慢性踝关节不稳定（CAI）患者存在神经肌肉功能缺陷，但之前的研究大多是孤立地研究多块肌肉的激活情况。研究 CAI 患者的肌肉协同作用可以提供关于神经肌肉激活策略的协调和控制的信息，并为理解和康复该人群的神经肌肉缺陷提供重要信息。
使用非负矩阵分解评估和比较 CAI 患者和健康对照组个体在进行不同的落地-切割任务时的肌肉协同作用。
横断面研究。
实验室。
共有 11 名 CAI 患者（5 名男性，6 名女性；年龄=22±3 岁，身高=1.68±0.11 m，体重=69.0±19.1 kg）和 11 名健康对照组个体（5 名男性，6 名女性；年龄=23±4 岁，身高=1.74±0.11 m，体重=66.8±15.5 kg）参与了本研究。
在预期和非预期落地-切割任务中，从外侧腓肠肌、内侧腓肠肌、腓骨长肌、比目鱼肌和胫骨前肌的肌电图中提取肌肉协同作用。比较组间和任务间协同作用的协同作用数量、激活系数和肌肉特异性加权系数。
每组和每项任务的肌肉协同作用数量相同。CAI 组在协同作用 1 中的 TA 加权系数大于对照组（P=.02）。此外，与预期的落地-切割任务相比，两组在非预期的落地-切割任务中协同作用 2 的腓骨长肌（P=.03）加权系数均更大。
这些结果表明，尽管两组都使用了类似复杂性或维度的神经肌肉控制策略来执行落地-切割任务，但 CAI 组在协同作用 1 中表现出不同的肌肉特异性加权，其特征是 TA 功能的强调更大，这可能反映了为了增加关节稳定性以补偿踝关节不稳定而进行的努力。
