Applying Supra- or Sub-Threshold Plantar Vibrations Increases the Toe Clearance While Stepping over an Obstacle

Area of Science:

• Biomechanics
• Neuroscience
• Motor Control

Background:

• Plantar sensation plays a crucial role in regulating gait and balance.
• Understanding how altered somatosensory feedback affects motor control is vital for rehabilitation.

Purpose of the Study:

• To investigate the impact of plantar vibrations on obstacle negotiation in healthy adults.
• To explore the effects of manipulated plantar sensation on gait parameters and joint kinematics.

Main Methods:

• Nineteen healthy adults participated in a controlled experiment.
• Participants stepped over obstacles under three conditions: no vibration, sub-threshold vibration, and supra-threshold vibration.
• Gait parameters, lower extremity joint angles, foot pressure, and foot area were measured using vibrotactile tactors.

Main Results:

• Both sub-threshold and supra-threshold plantar vibrations significantly increased toe clearance for the leading and trailing legs.
• Vibrations also led to increased foot integrated pressure and hip joint angles during the toe clearance phase.
• These changes suggest an adaptive motor response to altered plantar sensory input.

Conclusions:

• Plantar vibrations can modulate gait strategies, specifically enhancing obstacle clearance.
• Findings contribute to understanding sensorimotor integration and motor adaptation.
• This research may inform the development of novel rehabilitation protocols for individuals with somatosensory deficits.