Postural control and contingent negative variation during transient floor translation while standing with the ankle...

Area of Science:

• Neuroscience
• Biomechanics
• Motor Control

Background:

• Investigating postural muscle activity and anticipatory attention during transient floor translations.
• Examining adaptation changes in postural control strategies with a fixed ankle joint.

Purpose of the Study:

• To understand how fixing the ankle joint influences postural muscle activity and anticipatory attention during balance recovery.
• To identify adaptive changes in muscle activation patterns and brain potentials under altered postural control conditions.

Main Methods:

• 15 healthy adults underwent 40 anterior transient floor translations.
• Measured tibialis anterior (TA), rectus femoris (RF), and rectus abdominis muscle activity, alongside contingent negative variation (CNV).
• Compared conditions with and without ankle fixation, analyzing early and late adaptation phases.

Main Results:

• Ankle fixation shifted peak muscle activation from TA to RF, with RF showing increased activity.
• Adaptation led to decreased early CNV, particularly with ankle fixation.
• Correlation found between CNV peak and pre-S2 RF activation after adaptation with fixation.

Conclusions:

• Ankle fixation alters postural control, shifting primary muscle activation to the RF.
• Adaptation under fixation suggests a decline in early attentional demands and a shift in focus.
• Attentional focus appears to shift towards RF activation timing just before the perturbation.