Association Between Plantarflexion Torque Variability In Quiet Stance And During Force And Position Tasks

Area of Science:

• Biomechanics
• Motor Control
• Human Movement Science

Background:

• Plantarflexion torque variability is crucial for maintaining balance.
• Assessing balance typically involves complex standing tasks.
• Simpler, seated assessments could offer an alternative.

Purpose of the Study:

• To investigate the association between plantarflexion torque variability during quiet bipedal standing and during seated force-matching (FT) and position-matching (PT) tasks.
• To determine if FT and PT variability can predict balance ability.

Main Methods:

• Participants performed quiet bipedal standing (QS) on a force plate.
• Seated right leg FT and PT were performed using target torque levels derived from QS.
• Plantarflexion torque variability was measured as standard deviation (SD) with and without visual feedback.

Main Results:

• Significant correlations were found between QS torque variability and FT variability (r=0.86-0.88, p<0.001).
• Significant correlations were also found between QS and PT variability (r=0.73-0.80, p<0.01).
• No significant differences were observed between the strength of correlations for FT vs. PT.

Conclusions:

• Plantarflexion torque variability in seated FT and PT is strongly associated with balance control during standing.
• These seated tasks provide a reliable method for assessing balance ability.
• Rehabilitation programs can utilize seated FT and PT to improve balance function.