Foot segments motion during uneven terrain walking and influence on lower limb biomechanics.

Foot segments exhibited increased plantarflexion of the hallux and forefoot during uneven terrain walking compared to level walking.

• Twelve able-bodied young adults performed eight barefoot tasks at self-selected speed
• Tasks included level walking, obstacle crossing, and walking on uneven ground
• Multi-segment foot kinematics was quantified using the Oxford Foot Model
• Increased plantarflexion of the hallux and forefoot was observed during uneven terrain conditions

Forefoot and hindfoot showed increased dorsiflexion relative to the tibia during uneven terrain walking.

• Dorsiflexion increases were measured using the Oxford Foot Model
• These changes were observed across uneven ground walking tasks
• The pattern was consistent across the twelve able-bodied young adult participants
• These adaptations occurred alongside other kinematic compensatory strategies

Foot segments demonstrated a reduced range of motion during uneven terrain walking, suggesting a stiffening strategy to enhance grip and stability.

• Reduced range of motion was found across foot segments on uneven surfaces
• Authors interpreted this as 'a stiffening strategy to enhance grip and stability'
• This stiffening was identified as a key compensatory mechanism distinct from flat ground locomotion
• The strategy was observed in all uneven terrain conditions tested

Ankle dorsiflexion increased during uneven terrain walking, while knee and hip flexion also increased throughout the stance phase.

• Kinematic analysis was conducted using the lower-limb Plug-in Gait model
• Increased ankle dorsiflexion was a consistent finding across uneven terrain tasks
• Knee and hip flexion increases were observed throughout the stance phase
• These changes reflect compensatory strategies at multiple joints in the lower limb

Ankle plantarflexor torque increased during the first half of stance on uneven terrain, whereas push-off torque and power were reduced.

• Kinetic analysis was performed using the Plug-in Gait model
• Increased ankle plantarflexor torque was found specifically during the first half of stance
• Push-off torque and power were reduced compared to level walking conditions
• This pattern indicates an altered energy generation strategy at the ankle during uneven terrain walking

The knee exhibited increased energy dissipation during push-off on uneven terrain, with a tendency toward greater power generation during most of the single-support phase.

• Knee kinetics were analyzed as part of the lower-limb biomechanics assessment
• Increased energy dissipation at the knee was identified specifically during the push-off phase
• A tendency toward greater knee power generation was observed during most of the single-support phase
• These findings suggest a redistribution of mechanical work from the ankle to the knee during uneven terrain locomotion

The study identified an overall redistribution of joint function across the lower limb during uneven terrain walking.

• Findings highlight 'a redistribution of joint function and the pivotal role of foot segments kinematics and ankle dynamics in enabling stable locomotion on uneven terrain'
• The redistribution involved compensatory increases at the knee and hip to offset altered ankle push-off
• Both kinematic and kinetic data contributed to characterizing this redistribution
• The study was conducted with twelve able-bodied young adults performing barefoot tasks at self-selected speed