The effect of changes in tendon stiffness on muscular force production and neuro-motor control during childhood

肌腱硬度变化对儿童时期肌肉力量产生和神经运动控制的影响

• 批准号: EP/E013007/1
• 负责人: Thomas Korff
• 金额: $ 23.3万
• 依托单位: Brunel University London
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2007
• 资助国家: 英国
• 起止时间: 2007 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=EP%2FE013007%2F1
• 关键词: effect; changes; tendon; stiffness; muscular

The investigation of changes in muscular force production during childhood gives unique insights into the reasons why children change the way they perform movements. Factors that affect the development of muscular force production during childhood include growth and the biological maturation of the nervous system, the muscles and the tendons. These changes occur simultaneously and may have differing effects on muscle force production. Maturation of the nervous system is often used as an explanation for differences in children's force production. However, other factors influencing children's force production capabilities may be equally important. For example, we previously demonstrated that changes in body size and body proportions have significant effects on how children apply muscle forces to produce a given movement (Korff & Jensen, 2006a). Other factors that potentially affect children's muscle force production include the properties of the muscle-tendon complex and in particular the stiffness of the tendon.By storing and releasing mechanical energy, the tendon plays an integral role in the execution of movement. To make efficient use of this mechanism, muscle forces have to be applied with appropriate timing and at appropriate levels. Thus, optimal muscle activation is dependent on the mechanical structure of the tendon. If, for example, a child's tendon is more compliant, he/she may have to alter his/her muscle coordination to take full advantage of the energy storage potential of the tendon. In addition, the lesser tendon stiffness in children may increase the time necessary to transfer the force from the muscle to the bone, and may therefore limit children's ability to quickly produce a movement.The purpose of the proposed research is to determine the effect of age-related changes in tendon stiffness on muscular force production and muscle recruitment during both simple and complex movements. We will answer three questions:1. What are the age-related differences in tendon stiffness in children between 5 and 10 years of age?It has been reported that the stiffness of the tendon increases with increasing age (Lambertz et al., 2003). However, the available data are incomplete. We will systematically quantify changes in tendon stiffness in children between 5 and 10 years of age.2. What are the effects of age-related changes in tendon stiffness on muscular force development and muscle recruitment during simple motor tasks in children?Children develop muscular forces at a slower rate than adults. Possible causes are differences in muscle recruitment or in muscle-tendon properties. We propose to isolate the effect of tendon stiffness on the rate of muscular force development in children between 5 and 10 years of age. Muscle modelling will be used to quantify the effect of tendon stiffness on the magnitude and timing of muscle force during simple single joint movements.3. What is the effect of age-related changes in tendon stiffness on muscular force production during a complex movement in children?When performing motor tasks, children's muscle coordination is often different to that of adults, although the movement is identical. Previously, we have shown that during cycling, in spite of the movement being similar, children recruit their muscles differently than adults (Korff & Jensen, 2003, 2006b). A possible explanation is that these differences are a compensatory strategy to best utilise tendons that are less stiff. We will develop and use a paediatric biomechanical model to specifically test this hypothesis.The answers to these questions will refine the traditional assumption that children are miniature-adults and thus signify an important step toward a novel understanding of the reasons why children perform movements differently than adults. Results from this research will give teachers and clinicians information necessary to more accurately identify and treat abnormally developing children.

对儿童时期肌肉力量产生变化的调查，为儿童改变运动方式的原因提供了独特的见解。影响儿童期肌肉力量产生的因素包括神经系统、肌肉和肌腱的生长和生物成熟。这些变化同时发生，可能对肌肉力量产生不同的影响。神经系统的成熟通常被用来解释儿童力量产生的差异。然而，影响儿童力量产生能力的其他因素可能同样重要。例如，我们以前证明，身体大小和身体比例的变化对儿童如何应用肌肉力量来产生给定的运动有显着影响（Korff &詹森，2006 a）。其他可能影响儿童肌肉力量产生的因素包括肌肉-肌腱复合体的特性，特别是肌腱的刚度。通过储存和释放机械能，肌腱在运动的执行中起着不可或缺的作用。为了有效地利用这一机制，肌肉力量必须在适当的时间和适当的水平上施加。因此，最佳肌肉激活取决于肌腱的机械结构。例如，如果一个孩子的肌腱更顺从，他/她可能不得不改变他/她的肌肉协调，以充分利用肌腱的能量储存潜力。此外，儿童的肌腱刚度较小可能会增加将力从肌肉转移到骨骼所需的时间，因此可能会限制儿童快速产生运动的能力。这项研究的目的是确定与年龄相关的肌腱刚度变化对简单和复杂运动中肌肉力量产生和肌肉招募的影响。我们将回答三个问题：1。5至10岁儿童的肌腱僵硬度有哪些年龄相关差异？据报道，肌腱的刚度随着年龄的增加而增加（Lambertz等人，2003年）。然而，现有数据并不完整。我们将系统地量化5至10岁儿童肌腱硬度的变化。在儿童简单运动任务中，与年龄相关的肌腱硬度变化对肌力发育和肌肉募集有什么影响？儿童发展肌肉力量的速度比成人慢。可能的原因是肌肉募集或肌肉肌腱特性的差异。我们建议隔离肌腱刚度对5至10岁儿童肌肉力量发展速度的影响。肌肉建模将用于量化肌腱刚度对简单单关节运动期间肌肉力量的大小和时间的影响。在儿童复杂运动中，与年龄相关的肌腱刚度变化对肌肉力量产生的影响是什么？当执行运动任务时，儿童的肌肉协调性通常与成人不同，尽管运动是相同的。以前，我们已经表明，在骑自行车，尽管运动是相似的，儿童招募他们的肌肉不同于成人（Korff和詹森，2003年，2006年b）。一个可能的解释是，这些差异是一种补偿策略，以最好地利用不太僵硬的肌腱。我们将开发并使用一个儿科生物力学模型来专门验证这一假设，这些问题的答案将完善儿童是微型成人的传统假设，从而意味着朝着新的理解儿童与成人进行运动不同的原因迈出了重要的一步。这项研究的结果将为教师和临床医生提供必要的信息，以更准确地识别和治疗发育异常的儿童。