Time-to-contact demonstrates modulation of postural control during a dynamic lower extremity task

Area of Science:

• Biomechanics
• Motor Control
• Sports Science

Background:

• Postural control deficits increase injury risk.
• Evaluating balance during dynamic activities is crucial for assessing injury risk.
• Task-specific demands influence an individual's postural control capabilities.

Purpose of the Study:

• To evaluate changes in postural control during a dynamic lower extremity task.
• To utilize time-to-contact (TtC) analysis for assessing dynamic balance.
• To determine if postural control is adaptable to task difficulty.

Main Methods:

• Employed 3D motion capture and force plate technology.
• Analyzed 46 healthy recreational athletes performing a single-leg anterior reach task.
• Calculated and averaged time-to-contact (TtC) across five epochs for each trial.

Main Results:

• A significant main effect of epoch on TtC was observed (p<0.001).
• Later epochs (Epoch 4 and 5) showed significantly greater TtC compared to earlier epochs (p=0.05).
• Increased TtC in later epochs indicates heightened postural control demands as the task becomes more challenging.

Conclusions:

• Postural control is not fixed but dynamically adjusted to meet task demands.
• As the reaching foot extends further, individuals modify their postural control strategies.
• This adaptive response is essential for maintaining balance during complex movements.