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Published on: April 13, 2011
Stretch sensitive reflexes as an adaptive mechanism for maintaining limb stability
Jonathan Shemmell1, Matthew A Krutky, Eric J Perreault
1Sensory Motor Performance Program, Rehabilitation Institute of Chicago, Chicago, IL, USA.
Summary
The long-latency stretch reflex aids posture and movement control but its exact role is debated. This reflex is adaptable, suggesting it
Area of Science:
- Neuroscience
- Motor Control
- Biomechanics
Background:
- The stretch reflex is crucial for involuntary control of posture and movement.
- Controversy exists regarding the precise functional role of the stretch reflex.
- Task-dependent modulation of stretch reflexes is well-documented.
Purpose of the Study:
- To review the modulation of the long-latency stretch reflex (LLSR).
- To explore the role of supraspinal pathways in LLSR.
- To address the debate on whether LLSR stabilizes or destabilizes limb posture.
Main Methods:
- Review of existing studies on LLSR modulation.
- Analysis of reflex responses in compliant versus rigid environments.
- Examination of neural pathways contributing to LLSR.
Main Results:
- LLSR magnitude increases in compliant environments, suggesting a role in limb stability.
- Some studies show LLSR can destabilize posture, challenging a purely stabilizing role.
- Multiple, functionally distinct pathways contribute to the LLSR.
Conclusions:
- The LLSR is not a single entity but comprises multiple adaptable pathways.
- LLSR activity is highly sensitive to task demands.
- The LLSR should be viewed as an intelligent, adaptable neural process rather than a simple reflex.
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