Gait speed and multi-segment foot joint kinematics throughout the entire stance phase using statistical parametric mapping.

Faster walking increased ankle eversion and midfoot dorsiflexion during weight acceptance.

• The effects occurred at approximately 17-29% of the stance phase.
• Full time-series multiplanar foot joint kinematics were analyzed with statistical parametric mapping rather than discrete peak values.
• The authors interpret this as greater foot-arch collapse in early stance.

During propulsion, faster walking increased ankle plantar flexion and inversion.

• Ankle plantar flexion was increased at approximately 80-100% of stance.
• Ankle inversion was increased at approximately 82-90% of stance.

During propulsion, faster walking increased midfoot plantar flexion and adduction.

• Midfoot plantar flexion was increased at approximately 82-100% of stance.
• Midfoot adduction was increased at approximately 90-98% of stance.
• The authors interpret this as foot-arch recoil in late stance.

Faster walking increased first metatarsophalangeal joint dorsiflexion after heel-off.

• The effect spanned approximately 43-98% of stance.

The multiplanar kinematic changes across ankle-foot joints may facilitate energy absorption and generation as gait speed increases.

• Greater arch collapse in early stance and arch recoil in late stance are proposed to support appropriate energy absorption and generation.
• This interpretation is offered in the discussion of the observed kinematic patterns.

The continuous time-series approach revealed phase-dependent adaptations that previous discrete-measure analyses did not capture.

• Prior studies relied mainly on discrete measures such as peak joint angles.
• Statistical parametric mapping identified the specific portions of stance in which gait speed affected each joint's motion.
• The authors state that discrete analyses may obscure phase-dependent changes during gait.