Walking variability during continuous pseudo-random oscillations of the support surface and visual field

Area of Science:

• Biomechanics
• Human Movement Science
• Virtual Reality Applications

Background:

• Gait variability increases with uneven surfaces or perturbations.
• Previous studies used predictable sinusoidal oscillations, allowing adaptation.
• Pseudo-random perturbations offer a novel approach to assess gait stability.

Purpose of the Study:

• To investigate the effects of continuous, pseudo-random support surface and visual field oscillations on gait.
• To compare responses to anterior-posterior (AP) and mediolateral (ML) perturbations.
• To assess the impact on gait parameters and trunk stability.

Main Methods:

• 12 healthy young participants walked in a virtual reality environment.
• Conditions included no perturbation (NOP), AP oscillations, and ML oscillations.
• Gait parameters (step length, width, speed) and trunk variability were measured.

Main Results:

• ML and AP perturbations altered step length, width, and speed compared to NOP.
• Step length and width variability increased significantly under all perturbation conditions, especially ML.
• Trunk position and velocity variability were greater in the ML direction during ML perturbations.

Conclusions:

• Pseudo-random ML and AP perturbations significantly affect gait parameters and increase variability.
• Increased ML variability suggests a greater need for postural control in this direction.
• Findings support the use of ML visual and walking surface perturbations in gait training and assessment.