Related Experiment Video
Updated: May 1, 2026
10:41
Method to Measure Tone of Axial and Proximal Muscle
Published on: December 14, 2011
18.4K
Comparison of trunk muscle reflex activation patterns between active and passive trunk flexion-extension loading
1Southern Illinois University, Department of Kinesiology, 1075 S. Normal Avenue, Carbondale, IL 62901, United States.
Human Movement Science
|April 3, 2014
Summary
Repetitive trunk loading impacts neuromuscular responses. Females and abdominal muscles show shorter reflexive latencies, while thoracic paraspinals exhibit greater amplitudes, suggesting a specific stabilization strategy.
Area of Science:
- Biomechanics
- Neuroscience
- Exercise Physiology
Background:
- Understanding trunk neuromuscular control is crucial for injury prevention and rehabilitation.
- Repetitive loading can alter neuromuscular responses, but active versus passive loading effects are not fully elucidated.
Purpose of the Study:
- To investigate the effects of active and passive trunk flexion-extension loading on neuromuscular reflexive latencies and amplitude responses.
- To compare responses between paraspinal and abdominal muscles, and between sexes.
Main Methods:
- Eighteen participants (18-27 years) underwent active and passive trunk flexion-extension protocols.
- Surface electromyography (EMG) recorded bilateral paraspinal and abdominal muscle activity.
- Trunk perturbations were applied before and after 30 repetitions to assess reflexive responses.
Main Results:
- No significant differences were found between active and passive loading conditions, sides, or perturbation sessions.
- Reflexive latencies were shorter in females compared to males and in abdominal muscles compared to paraspinals.
- Thoracic paraspinal muscle EMG amplitudes were greater than other trunk muscles.
Conclusions:
- The neuromuscular system activates abdominal muscles before paraspinals during flexion to stabilize the trunk.
- Repetitive trunk loading elicits similar neuromuscular responses regardless of whether the loading is active or passive.
More Related Videos
Related Concept Videos
01:22Somatic Spinal Reflexes
7.8K
Somatic spinal reflexes are rapid, involuntary muscular responses to external stimuli that involve the somatic musculature and the spinal cord.
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
One of the most well-known somatic spinal reflexes is the stretch reflex, which is activated by the sudden stretching of a muscle. This reflex involves the activation of specialized sensory receptors called muscle spindles, which are located in the muscle tissue and detect changes in the length and speed of muscle contractions. When a muscle is suddenly...
7.8K
01:08Reflex Activity
5.1K
A reflex activity is an automatic, involuntary response to specific stimuli. It is a part of our survival mechanism, designed to protect us from potential harm. For example, when a bright light suddenly shines into our eyes, we instinctively close them or look away. This is a simple reflex activity orchestrated by the nervous system without conscious thought or effort.
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
A reflex exam is a diagnostic procedure performed by a healthcare professional to evaluate the functionality of a patient's...
5.1K
01:20Motor Unit Stimulation
4.7K
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...
4.7K