Biomechanical Modeling of Posture and Movement Coordination: Fatigue, Gender and Aging effects

重复的运动通常是在日常生活活动中完成的，可能会导致疲劳。疲劳对个体肌肉和关节的影响已经被很好地记录下来；我们是第一批描述重复运动引起的疲劳的全身后果的人之一，揭示了利用肌肉骨骼系统的冗余的策略。我们发现，健康的疲劳适应与高度的运动变异性以及随着疲劳的发展而招募更多的关节和肌肉来完成任务有关。这些适应与跨越感觉、本体感觉和运动系统的变化有关。然而，性别和年龄等个人因素对工作相关疲劳适应能力的影响还不是很清楚，这限制了力学模型在准确表达正常健康疲劳适应模式范围方面的有效性。最近的统计数据显示，女性报告与工作有关的颈部/肩部MSD的比率较高。我之前已经发表了一个基于感觉运动控制基本知识的理论模型来解释这种观察；然而，这个模型的许多元素还没有确定。此外，加拿大人口预期寿命的持续增长、加拿大劳动力的老龄化和退休年龄的提高，使我们有必要了解老龄化如何影响一个人的适应疲劳的能力，无论是男性还是女性。这项研究计划的总体长期目标是更好地了解健康人上肢重复运动的生物力学和控制方面。现在将使用以下具体目标来解决这一问题：1)衡量

Repetitive motions are often accomplished during activities of daily living and can lead to fatigue. The effects of fatigue on individual muscles and joints have been well documented; we were among the firsts to describe the whole-body consequences of repetitive motion-induced fatigue, uncovering strategies that take advantage of the musculoskeletal system’s redundancy. We showed that healthy fatigue adaptations were associated with high movement variability and the recruitment of additional joints and muscles to contribute to the task as fatigue develops. These adaptations have been related to changes spanning the sensory, proprioceptive and motor systems. However, the effects of personal factors such as gender and aging on the ability to adapt to work-related fatigue is not well known, limiting the validity of mechanical models in accurately conveying the range of normal healthy fatigue adaptations patterns. Recent statistics show that women display a higher rate of reporting work-related neck/shoulder MSD. I have previously published a theoretical model based on fundamental knowledge of sensorimotor control to explain this observation; however, many elements of this model have not been identified yet. Moreover, the consistently increasing life expectancy of the Canadian population, the aging of the Canadian workforce and the increasing retirement age make it important for us to understand how aging affects one’s ability to adapt to fatigue, in both men and women. The general, long-term objective of this research program is to gain a better understanding of the biomechanics and control aspects of upper limb repetitive movements in healthy humans. This will now be addressed using the following specific objectives: 1) Measure the effects of