Assessing trunk motor variability in a changing spinal environment: an experimental study.

运动变异性是人体运动的重要特征，其可以使用多个参数来测量，例如性能测量、运动模式的运动学和动力学分量、肌肉活动和肌肉募集模式。这项建议的主要目的是确定和表征躯干神经肌肉和运动学适应“不断变化的脊柱环境”。拟议的研究计划将包括一系列实验，旨在解决每个特定的假设相关的躯干和脊髓运动变异性在不同的机械和神经生理条件下。这些研究的结果将为复杂的肌肉骨骼脊柱系统的急性和长期运动适应的发展提供关键信息。从长远来看，从这些研究中获得的结果和知识可以提供关于如何将内在脊柱变异性作为生物力学变异的来源而不影响工作相关或其他类型的性能的新见解。这项具体工作的潜在长期应用包括人体工程学风险评估、客观的“重返工作算法”以及标准化脊柱功能评估和临床诊断工具的开发。方法所有提出的实验将基于一个类似的实验方案，旨在量化神经力学适应各种实验条件下使用躯干肌肉活动记录与大表面电极矩阵以及腰椎和骨盆运动。将研究屈伸任务和躯干肌肉耐力，因为它们都提供了研究具有高度可重复的肌肉活动和运动特征的标准化神经肌肉反应的可能性。将招募独立的健康成年参与者组参与这些实验中的每一个（每个实验N= 40），并且将要求他们在不同的实验条件下进行一系列标准化躯干屈曲和伸展。关于运动变异性，建议的各种实验将试图回答以下研究问题：[1]竖脊肌疲劳如何改变躯干肌招募策略和运动学？[2]腹部肌肉疲劳如何改变躯干肌肉募集策略和运动学？[3]被动脊柱稳定性的变化如何影响躯干肌的募集策略和运动学？[4]伤害性节段性输入如何影响躯干肌募集策略和运动学？ 在各种实验任务期间，将使用EMG矩阵中肌肉活动的空间表示来量化神经肌肉运动变异性。将使用运动变异性的多个特征评估竖脊肌和腹肌中肌肉活动的空间重组。还将通过研究腰椎和骨盆之间的运动相互作用来评估与躯干运动相关的运动变异性。我的目标，与目前的建议，是为研究生创造一个教育环境，将促进跨学科的合作，以确保在运动控制，生物力学和信号处理领域的年轻研究人员的多样化和高质量的培训。目前与电气工程系的合作已经导致了研究肌肉招募和运动组织的创新方法的发展。

Motor variability is an important feature of human movement which can be measured using multiple parameters such as performance measures, kinematic and kinetic components of the movement pattern, muscle activity and muscle recruitment patterns. The main objective of this proposal is to identify and characterize trunk neuromuscular and kinematic adaptations to a “changing spinal environment”. The proposed research program will include a series of experiments designed to each address a specific hypothesis related to trunk and spinal motor variability under varying mechanical and neurophysiological conditions. The results of these studies will provide critical information regarding the development of acute and long term motor adaptation in the complex musculoskeletal spinal system. The results and knowledge derived from these studies could, in the long run, provide new insights on how intrinsic spinal variability can be exploited as a source of biomechanical variation without compromising work-related or other type of performances. Potential long term applications of this specific work include risk assessment in ergonomics, objective “return to work algorithm” as well as the development of standardized functional spinal evaluation and clinical diagnostic tools. METHODS All the proposed experiments will be based on a similar experimental protocol aimed at quantifying neuromechanical adaptations to various experimental conditions using trunk muscular activity recordings with large surface electrode matrices as well as lumbar spine and pelvis movements. A flexion-extension task and trunk muscle endurance will be studied as they both offer the possibility to investigate a standardized neuromuscular response with highly reproducible muscle activity and movement characteristics. Independent groups of healthy adult participants will be recruited to participate in each of these experiments (N= 40 per experiment) and will be asked to perform a series of standardized trunk flexion and extension under varying experimental conditions. With regard to motor variability, the various experiments suggested will try to answer the following research questions: [1] How does erector spinae muscle fatigue change trunk muscle recruitment strategies and kinematics? [2] How does abdominal muscle fatigue change trunk muscle recruitment strategies and kinematics? [3] How do changes in passive spinal stability affect trunk muscle recruitment strategies and kinematics? [4] How do nociceptive segmental inputs affect trunk muscle recruitment strategies and kinematics? Neuromuscular motor variability will be quantified using the spatial representation of muscular activity in EMG matrices during the various experimental tasks. Spatial reorganization of muscular activity in erector spinae and abdominal muscles will be assessed using multiple features of motor variability. Motor variability related to trunk movement will also be assessed by studying the movement interaction between the lumbar spine and the pelvis. My goal, with the present proposal, is to create an educational environment for graduate students that will foster interdisciplinary collaboration in order to ensure both diversified and high quality training of young researchers in the fields of motor control, biomechanics and signal processing. Current collaborations with the electrical engineering department have already led to the development of innovative approaches to the study muscle recruitment and movement organization.