Lateral reactive stepping responses differ between individuals with and without transfemoral amputation.

Area of Science:

• Biomechanics
• Rehabilitation Science
• Human Movement Science

Background:

• Falls are a significant concern for individuals with transfemoral amputation (TFA).
• Reactive stepping is crucial for maintaining balance and preventing falls.
• Mediolateral reactive stepping in individuals with TFA is not well understood.

Purpose of the Study:

• To investigate limb-specific mediolateral reactive stepping responses in individuals with TFA compared to healthy controls.
• To analyze differences in step thresholds, stepping strategies, step latency, and center of pressure (CoP) metrics.

Main Methods:

• Seventeen individuals with TFA and seventeen healthy controls participated.
• Lateral perturbations were applied at the waist using a custom system.
• Responses were analyzed for perturbations loading the prosthetic limb, sound limb, or control's dominant limb.

Main Results:

• Step thresholds did not differ significantly based on the loaded limb.
• Individuals with TFA exhibited longer step latency and different stepping strategies compared to controls.
• Perturbations loading the prosthetic limb in individuals with TFA resulted in more crossover steps and greater CoP path length than when loading the sound limb.

Conclusions:

• Individuals with TFA demonstrate altered timing and execution of mediolateral reactive stepping.
• The prosthetic limb's response to perturbations is particularly affected, impacting balance control.
• Findings highlight the need for targeted interventions to improve reactive stepping in individuals with TFA.