准备着陆:一个简单的激活策略将肌肉力量调整为着陆高度
Nicolai Konow1, Thomas J Roberts2
1Department of Biological Sciences, University of Massachusetts Lowell, Lowell MA 01854, USA.
Journal of biomechanics
|March 2, 2024
概括
动物在着陆时调整肢体硬性,通过调整肌肉预激活的持续时间与跌落高度成比例. 这确保了腿部度与冲击强度相匹配,可能没有感知掉落距离.
科学领域:
- 生物力学 生物力学
- 神经科学是一个神经科学.
- 动物生理学 动物生理学
背景情况:
- 动物在降落前预先激活肌肉以使关节变硬.
- 肌肉如何调整硬度和预测冲击力仍然不清楚.
- 之前的研究表明,无论下降的持续时间如何,肌肉预激活的持续时间是恒定的.
研究的目的:
- 研究动物在着陆时如何调整四肢硬.
- 确定肌肉预激活是否根据跌倒时间或冲击强度进行调整.
- 了解预期四肢硬化的机制.
主要方法:
- 在降落过程中测量了火的侧面胃口肌肉力和肌肉力.
- 多种下降高度改变下降时间和冲击强度.
- 分析了肌肉活动的发病时间,预激活的持续时间,以及脚下面的力量.
主要成果:
- 肌肉预激活的持续时间与跌落高度 (跌落高度) 相称.
- 肌肉力量增加的速度在不同的下降高度中是一致的.
- 降落时的力和腿的度与跌落高度成比例地增加.
- 肌肉活动的开始延迟了22±7毫秒的下降开始,这表明反射开始.
结论:
- 肢体刚度与降落期间的冲击强度成比例调整.
- 一定速率的动力单元招募,在下降开始时启动,提供高度依赖的预激活.
- 这种机制允许成比例的四肢硬化,而无需明确感知跌落距离.
相关概念视频
Motor 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
Muscle Stimulation Frequency
2.2K
The contraction strength of muscles is regulated by motor neurons, which modulate the frequency of action potentials dispatched to the motor units based on the body's requirements. This process of varying the muscle stimulation frequency allows muscles to contract with a force that is precisely tailored to the needs of the moment, whether lifting a feather or a heavy box.
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
Wave summation
At low firing rates, motor neurons induce individual twitch contractions in muscle fibers. These twitches...
2.2K
Impact: Problem Solving
223
In an experiment conducted during a Mars mission, a rover propels a projectile with an initial velocity, and the projectile rebounds after colliding with the Martian surface. To ascertain the maximum height attained by the projectile after this collision, the known restitution coefficient and acceleration due to gravity are employed.
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
By designating the launch point as the origin and utilizing kinematic equations, the vertical component of the projectile's velocity at the point of impact is...
223
Isotonic and Isometric Muscle Contractions
3.2K
Two primary types of muscle contractions are isotonic and isometric, each serving unique functions and involving distinct mechanisms. Both isotonic and isometric contractions are integral to the body's complex system of movement and stability. Isotonic exercises contribute significantly to functional strength and movement, while isometric contractions are crucial for maintaining posture and joint stability.
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
Isotonic contractions
Isotonic contractions occur when a muscle changes length while...
3.2K


