Muscular tension significantly affects stability in standing posture

Area of Science:

• Neuroscience
• Biomechanics
• Gerontology

Background:

• Elderly individuals often use muscle co-contraction to enhance stability, but this paradoxically increases stiffness and reduces balance.
• Emerging research suggests relaxation, not tension, may improve stability, creating a need to clarify optimal muscular strategies.
• The concept of relaxation is often misunderstood, frequently confused with rest rather than a technique to reduce energetic costs and improve stability during stress.

Purpose of the Study:

• To investigate the impact of voluntary muscle contraction and relaxation on the stability of human standing posture.
• To determine if muscular tension negatively affects standing posture stability.
• To assess if this impact can be measured using a minimally invasive procedure.

Main Methods:

• Analyzed center of pressure displacement using a force plate in 30 volunteers.
• Compared stability during states of tension and relaxation against a control state.
• Evaluated the effect of open and closed eyes on stability measurements.

Main Results:

• Muscle tension significantly decreased standing posture stability across 15 out of 16 measured parameters (p < 0.003).
• This finding indicates a direct negative correlation between muscular tension and postural control.
• The results suggest that increased tension leads to poorer balance.

Conclusions:

• Daily stress can lead to decreased stability, increasing the risk of joint overload and falls.
• The inability to relax, potentially due to sub-optimal neuro-motor control, is linked to reduced stability.
• Proper breathing techniques are crucial for pain and stress management, and a significant portion of the population may struggle with effective breathing, impacting stability.