Leg Dominance-Surface Stability Interaction: Effects on Postural Control Assessed by Smartphone-Based Accelerometry.

Area of Science:

• Biomechanics
• Sports Medicine
• Neuromuscular Control

Background:

• Leg dominance is a known internal risk factor for lower-limb injuries in sports.
• Understanding how leg dominance affects postural control is crucial for injury prevention and rehabilitation strategies.

Purpose of the Study:

• To investigate the influence of leg dominance on postural control during unipedal balancing.
• To examine the effects of varying surface instability on postural control related to leg dominance.
• To analyze the interaction between leg dominance and surface stability on postural sway.

Main Methods:

• Utilized a tri-axial accelerometer-based smartphone sensor placed at the lumbar spine (L5) to record postural accelerations in 22 young adults.
• Applied Sample Entropy (SampEn) to acceleration data to quantify postural sway regularity and complexity.
• Assessed postural control during unipedal balancing on firm, foam, and multiaxial balance board surfaces.

Main Results:

• Significant effects of leg dominance and surface interaction were observed across all acceleration directions (p < 0.001).
• Balancing on the dominant leg resulted in more irregular postural acceleration fluctuations (higher SampEn), suggesting greater postural control efficiency.
• Interaction effects indicated that training on unstable surfaces may be beneficial for reducing interlimb differences.

Conclusions:

• Leg dominance significantly influences postural control during unipedal balancing.
• Unstable surfaces amplify differences in postural control between dominant and non-dominant legs.
• Unipedal balancing training on unstable surfaces is recommended to enhance neuromuscular control and prevent injuries.