Related Experiment Video
Updated: Aug 23, 2025
09:48
Intracortical Inhibition Within the Primary Motor Cortex Can Be Modulated by Changing the Focus of Attention
Published on: September 11, 2017
10.0K
Synergic control in asymptomatic welders during multi-finger force exertion and load releasing while standing
Paulo B de Freitas1, Sandra M S F Freitas2, Janina M Prado-Rico3
1Interdisciplinary Graduate Program in Health Science, Universidade Cruzeiro do Sul, São Paulo, SP, Brazil.
Neurotoxicology
|October 29, 2022
Summary
Occupational metal exposure in welders impairs postural stability and motor control, linked to brain changes. This neurotoxicity affects load releasing tasks, highlighting risks for worker health.
Area of Science:
- Neuroscience
- Occupational Health
- Biophysics
Background:
- Motor synergies are crucial for action stability and are affected by neurological conditions.
- Welders, exposed to metals, may experience neurological impairments affecting motor control.
- Previous studies indicated impaired multi-finger synergy in asymptomatic welders linked to globus pallidus damage.
Purpose of the Study:
- To investigate the impact of welding-related metal exposure on multi-finger and posture-stabilizing motor synergies.
- To explore associations between brain metal content, microstructural integrity, and motor synergy in welders.
- To assess potential neurotoxic effects of chronic metal exposure in occupational settings.
Main Methods:
- Utilized MRI (R2* for iron, R1 for manganese) and diffusion tensor imaging to assess brain changes in 29 welders and 19 controls.
- Measured motor synergies during multi-finger force production and a standing load-releasing task.
- Analyzed associations between brain MRI metrics (globus pallidus, caudate, putamen, red nucleus) and motor synergy indices.
Main Results:
- Welders showed higher R2* values (indicating iron accumulation) in the caudate, putamen, and red nucleus compared to controls.
- No significant group difference in multi-finger synergy during steady-state action.
- Welders exhibited altered postural synergy (lower ΔVZss) during load releasing, negatively correlated with red nucleus R2* values.
Conclusions:
- Chronic metal exposure in welders is associated with neurotoxic effects impacting postural stability and motor control during load-releasing tasks.
- Postural synergy may serve as a sensitive indicator of welding-related neurotoxicity.
- Findings have significant implications for occupational health surveillance and preventative strategies for workers exposed to metals.
Related Concept Videos
01:24Muscle Coordination and Action
1.8K
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....
1.8K
01:20Motor Unit Stimulation
1.7K
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...
1.7K
01:22Machines: Problem Solving I
390
A toggle clamp is a mechanical device commonly used for holding and clamping objects in various applications, such as woodworking, metalworking, and assembly operations. Consider a toggle clamp subjected to a force of 200 N at the handle. The vertical clamping force can be calculated, provided the dimensions of the toggle clamp are known.
The toggle clamp system is a machine structure consisting of movable, pin-connected multi-force members that form a stabilized system to transmit forces. The...
The toggle clamp system is a machine structure consisting of movable, pin-connected multi-force members that form a stabilized system to transmit forces. The...
390