Metatarsophalangeal Joint Dynamic Stiffness During Toe Rocker Changes With Walking Speed

Area of Science:

• Biomechanics
• Human locomotion
• Orthotics and prosthetics

Background:

• Dynamic joint stiffness is crucial for tuning orthotic and prosthetic device properties.
• Understanding metatarsophalangeal (MTP) joint behavior during walking is essential for improving device design.
• Previous research lacked baseline data on MTP joint stiffness across various walking speeds.

Purpose of the Study:

• To examine MTP joint stiffness during the toe-rocker phase of barefoot walking.
• To establish baseline characteristics of MTP joint stiffness in healthy individuals.
• To provide data for designing advanced orthotic and prosthetic devices that mimic natural foot motion.

Main Methods:

• Ten healthy participants walked at four controlled speeds (0.4-1.0 statures·s-1).
• MTP joint angles and moments in the sagittal plane were recorded during the toe-rocker phase.
• Least-squares linear regressions and multilevel linear models were used to analyze joint stiffness and speed effects.

Main Results:

• Early toe rocker MTP joint stiffness was positive; late toe rocker stiffness was negative.
• The magnitude of both early and late toe rocker stiffness significantly increased with walking speed.
• This study provides the first comprehensive baseline data on MTP joint stiffness across a range of walking speeds.

Conclusions:

• Baseline MTP joint stiffness characteristics during barefoot walking were established.
• Findings reveal a speed-dependent modulation of MTP joint stiffness.
• This data can inform the design of orthotic and prosthetic devices to better replicate natural human gait.