运动单元活动模式的发育变化:使用离散运动单元分析对儿童和成人进行比较
Stacey Woods1, Andrew McKiel1,2, Trent Herda3
1Department of Kinesiology, Brock University, St. Catharines, ON, Canada.
概括
儿童和男性在膝盖延伸过程中表现出不同的运动单元激活策略. 与男性相比,男孩表现出较低的动力单元发射率和较低的招募高门动力单元.
科学领域:
- 神经肌肉生理学 神经肌肉生理学
- 发育运动控制 发育运动控制
背景情况:
- 以前使用表面电肌图 (sEMG) 的研究表明,儿童激活II型运动单元 (MU) 比成年人少.
- 然而,使用sEMG分解的研究显示了与年龄相关的离散MU激活差异的相互矛盾的结果.
研究的目的:
- 调查男孩和男性之间巨大的横向肌 (VL) 的离散MU激活的差异.
- 为了比较MU动作潜能幅度,招募值和在中等强度膝盖延伸期间的射击率.
主要方法:
- 用表面电肌图 (sEMG) 分解来分析个体的MU活动.
- 参与者在他们的最大自愿同度膝盖延伸 (MVIC) 的70%时进行了梯形收缩.
- 计算的参数包括MU动作潜能幅度 (MUAPamp),招募值 (RT) 和MU发射率 (MUFR).
主要成果:
- 男性的MUAPamp-RT斜率比男孩更 (p < 0.05),即使调整了组织深度.
- 与男性相比,男孩的MUFR平均值和MUFR-RT关系的y截面显著较低 (p < 0.001).
- 在男性中,MUFR-RT关系的斜率趋势更为,但没有达到统计学意义 (p = 0.056).
结论:
- 对于产生扭矩的神经策略在男孩和男性之间有所不同.
- 男孩的较低的MUFR和减少招募更高值MU的能力有助于这些差异.
- 肌肉组成和其他因素也可能影响与年龄有关的神经肌肉适应.
相关概念视频
01:13Motor Units
3.9K
The motor unit is a fundamental component of the neuromuscular system and plays a crucial role in coordinating muscle contractions. It consists of a somatic motor neuron, which connects and controls multiple skeletal muscle fibers, forming a single functional segment. The axon of the motor neuron branches out and establishes synaptic connections known as neuromuscular junctions with individual muscle fibers within the motor unit.
Motor units come in different sizes, with smaller units...
Motor units come in different sizes, with smaller units...
3.9K
01:20Motor Unit Stimulation
1.6K
When the neuron of a motor unit fires an action potential, it triggers a series of events, leading to a twitch contraction in the muscle fibers. The process of excitation-contraction coupling is crucial in relaying the action potential to the muscle fibers.
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
The latent period of contraction marks the onset of excitation-contraction coupling, when the action potential propagates across the sarcolemma, preparing the muscle fibers for contraction. As the fibers enter the contraction phase, the...
1.6K