Related Experiment Video
Updated: Jun 2, 2026
07:03
"Avatar", a Modified Ex vivo Work Loop Experiments Using In vivo Strain and Activation
Published on: August 18, 2023
Mechanics, modulation and modelling: how muscles actuate and control movement
Timothy E Higham1, Andrew A Biewener, Scott L Delp
1Department of Biological Sciences, Clemson University, 132 Long Hall, Clemson, SC 29634, USA. thigham@clemson.edu
Summary
Understanding complex animal movement requires studying muscle function. Recent technological advances and a focus on diverse locomotor behaviors are revolutionizing the field of neuromuscular mechanics.
Area of Science:
- Biomechanics and neuromuscular systems.
- Integrative biology and comparative physiology.
Background:
- Muscle function has been studied for centuries, but new technologies like sonomicrometry and ultrasound are refining in vivo measurements.
- Advancements in computational tools have improved musculoskeletal models, enabling better simulation of muscle-tendon dynamics during movement.
Discussion:
- The field is shifting focus to complex, unsteady animal locomotion (e.g., swimming, flying, jumping) over simpler, steady movements.
- This Theme Issue explores muscle function across diverse taxa, from humans to insects, examining various locomotor behaviors.
Key Insights:
- Emerging techniques and a focus on complex behaviors are rapidly advancing our understanding of muscle function in locomotion.
- Studies on walking and running have direct implications for clinical movement analysis and sports science.
Outlook:
- Future research will integrate diverse taxa and complex behaviors, building on recent advances in neuromuscular control and biomechanical modeling.
- Developments in powered prosthetics and advanced modeling techniques are expected to further enhance our understanding and application of muscle function.
Related Concept Videos
01:28An Introduction to Mechanics
Humans have been making ships, shelters, pyramids, weapons, agricultural equipment, and many more items without recording the process or theory behind them for centuries. It would be challenging to document the evolution of mechanics from its origin to the present.
According to records, the history of mechanics starts with Aristotle (384–322 BC). He related mechanics to physical theory, aiming for a universal synthesis.
Newton defined mechanics as the branch of physical science that studies the...
According to records, the history of mechanics starts with Aristotle (384–322 BC). He related mechanics to physical theory, aiming for a universal synthesis.
Newton defined mechanics as the branch of physical science that studies the...
01:20Motor Unit Stimulation
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...
01:24Muscle Coordination and Action
Muscle coordination is a complex and finely tuned process essential for smooth and purposeful movements like flexion, extension, adduction, abduction, and rotation. The human body orchestrates the actions of various muscles working in concert, each with a specific role. Four functional types describe how muscles work together: agonist, antagonist, synergist, and fixator.
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement.
Agonists
Agonist muscles, often called prime movers, are the primary muscles responsible for producing a specific movement.
01:13Motor Units
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...
00:46Motor Units
A motor unit consists of two main components: a single efferent motor neuron (i.e., a neuron that carries impulses away from the central nervous system) and all of the muscle fibers it innervates. The motor neuron may innervate multiple muscle fibers, which are single cells, but only one motor neuron innervates a single muscle fiber.
01:19The Neuromuscular Junction
The nervous system consists of complex motor neuron circuits, including upper motor neurons originating from the cerebral cortex and lower motor neurons starting in the spinal cord, coordinating both voluntary and involuntary movements. Among these, somatic motor neurons activate skeletal muscles and are classified into alpha, beta, and gamma types. Alpha neurons are vital for voluntary movement coordination, while gamma neurons adjust muscle spindle sensitivity, and the function of beta...