Single-Leg Balance: Bias for the Non-Preferred Leg in Complex Tasks, But no Association with Footedness

Area of Science:

• Biomechanics
• Motor Control
• Human Movement Science

Background:

• Lower limbs exhibit symmetrical control in simple single-leg balance (SLB) tasks.
• Balance asymmetries are hypothesized to increase with task complexity.
• Foot preference may influence performance asymmetries in balance tasks.

Purpose of the Study:

• To investigate if increased task complexity elevates asymmetries in single-leg balance.
• To determine if foot preference correlates with performance asymmetries during balance tasks.

Main Methods:

• Twenty-seven right-footed adults performed SLB on stable and unstable surfaces.
• Balance performance was assessed using center of pressure displacement and area.
• Task complexity was manipulated via surface stability (stable floor vs. unstable platform).

Main Results:

• Task complexity altered asymmetry direction, favoring the left leg on the unstable surface.
• The magnitude of balance asymmetries did not significantly increase between stable and unstable conditions.
• No significant correlation was found between foot preference and performance asymmetry.

Conclusions:

• Increased task complexity in balance tasks can reveal directional asymmetries.
• Hemispheric specificity in motor control for balance may require more complex tasks to manifest.
• Foot preference is not a reliable predictor of performance asymmetry in single-leg balance tasks.