Neuroplastic alterations in common synaptic inputs and synergistic motor unit clusters controlling the vastii muscles of individuals with ACL reconstruction.

IF 3.3 3区 医学 Q1 PHYSIOLOGY
Journal of applied physiology Pub Date : 2024-10-01 Epub Date: 2024-07-18 DOI:10.1152/japplphysiol.00056.2024
Stefano Nuccio, Carina M Germer, Andrea Casolo, Riccardo Borzuola, Luciana Labanca, Jacopo E Rocchi, Pier Paolo Mariani, Francesco Felici, Dario Farina, Deborah Falla, Andrea Macaluso, Paola Sbriccoli, Alessandro Del Vecchio
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引用次数: 0

Abstract

This cross-sectional study aims to elucidate the neural mechanisms underlying the control of knee extension forces in individuals with anterior cruciate ligament reconstruction (ACLR). Eleven soccer players with ACLR and nine control players performed unilateral isometric knee extensions at 10% and 30% of their maximum voluntary force (MVF). Simultaneous recordings of high-density surface electromyography (HDEMG) and force output were conducted for each lower limb, and HDEMG data from the vastus lateralis (VL) and vastus medialis (VM) muscles were decomposed into individual motor unit spike trains. Force steadiness was estimated using the coefficient of variation of force. An intramuscular coherence analysis was adopted to estimate the common synaptic input (CSI) converging to each muscle. A factor analysis was applied to investigate the neural strategies underlying the control of synergistic motor neuron clusters, referred to as motor unit modes. Force steadiness was similar between lower limbs. However, motor neurons innervating the VL on the reconstructed side received a lower proportion of CSI at low-frequency bandwidths (<5 Hz) compared with the unaffected lower limbs (P < 0.01). Furthermore, the reconstructed side demonstrated a higher proportion of motor units associated with the neural input common to the synergistic muscle, as compared with the unaffected lower limbs (P < 0.01). These findings indicate that the VL muscle of reconstructed lower limbs contribute marginally to force steadiness and that a plastic rearrangement in synergistic clusters of motor units involved in the control of knee extension forces is evident following ACLR.NEW & NOTEWORTHY Chronic quadriceps dysfunction is common after anterior cruciate ligament reconstruction (ACLR). We investigated voluntary force control strategies by estimating common inputs to motor neurons innervating the vastii muscles. Our results showed attenuated common inputs to the vastus lateralis and plastic rearrangements in functional clusters of motor neurons modulating knee extension forces in the reconstructed limb. These findings suggest neuroplastic adjustments following ACLR that may occur to fine-tune the control of quadriceps forces.

前交叉韧带重建患者控制大腿肌肉的共同突触输入和协同运动单元群的神经可塑性改变。
这项横断面研究旨在阐明前交叉韧带重建(ACLR)患者控制膝关节伸展力的神经机制。11 名患有前交叉韧带重建术的足球运动员和 9 名对照组球员分别以最大自主力量(MVF)的 10% 和 30% 进行单侧等长膝关节伸展运动。对每个下肢同时进行了高密度表面肌电图(HDEMG)和力输出的记录,并将来自外侧肌(VL)和内侧肌(VM)的 HDEMG 数据分解为单个运动单元尖峰序列。使用力的变异系数来估计力的稳定性。采用肌内一致性分析来估计汇聚到每块肌肉的共同突触输入(CSI)。应用因子分析研究了控制协同运动神经元群(称为运动单元模式)的神经策略。下肢肌肉的力量稳定性相似。然而,与未受影响的下肢相比,重建侧支配VL的运动神经元在低频带宽(< 5 Hz)接收到的CSI比例较低(P < 0.01)。此外,与未受影响的下肢相比,重建侧显示出更高比例的运动单元与协同肌肉的共同神经输入相关(P < 0.01)。这些研究结果表明,再造下肢的 VL 肌肉对力量稳定性的贡献微乎其微,而且前交叉韧带重建术后,参与膝关节伸展力控制的协同运动单位群的可塑性重新排列是显而易见的。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
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来源期刊
CiteScore
6.00
自引率
9.10%
发文量
296
审稿时长
2-4 weeks
期刊介绍: The Journal of Applied Physiology publishes the highest quality original research and reviews that examine novel adaptive and integrative physiological mechanisms in humans and animals that advance the field. The journal encourages the submission of manuscripts that examine the acute and adaptive responses of various organs, tissues, cells and/or molecular pathways to environmental, physiological and/or pathophysiological stressors. As an applied physiology journal, topics of interest are not limited to a particular organ system. The journal, therefore, considers a wide array of integrative and translational research topics examining the mechanisms involved in disease processes and mitigation strategies, as well as the promotion of health and well-being throughout the lifespan. Priority is given to manuscripts that provide mechanistic insight deemed to exert an impact on the field.
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