Amputee Locomotion: Ground Reaction Forces During Submaximal Running With Running-Specific Prostheses

Area of Science:

• Biomechanics
• Kinesiology
• Prosthetics

Background:

• Lower extremity amputation necessitates adaptation in foot-ground mechanical interactions due to musculoskeletal function loss.
• Understanding how individuals with amputation modulate three-dimensional ground reaction forces (GRFs) during running is crucial but not well-established.

Purpose of the Study:

• To investigate the influence of running-specific prostheses on three-dimensional ground support forces during running.
• To compare GRFs between prosthetic limbs, intact limbs, and control limbs across different running speeds.

Main Methods:

• Eight individuals with unilateral transtibial amputations and eight control subjects ran at 2.5, 3.0, and 3.5 m/s.
• Ten force plates collected three-dimensional GRFs at 1000 Hz.
• Analysis focused on peak and average GRFs and impulses in each plane, comparing between limbs and groups.

Main Results:

• Prosthetic limbs exhibited reduced vertical impulses, braking forces/impulses, and mediolateral forces, but similar propulsive impulses compared to intact and control limbs.
• Intact limbs of amputees showed greater peak/average vertical forces and average braking forces than control limbs.
• The nonamputated limb of individuals with amputation experiences elevated mechanical loading.

Conclusions:

• Individuals with amputation adapt to prosthesis limitations by prolonging positive impulse periods, achieving equivalent propulsive impulses.
• Elevated loading on the intact limb may increase the risk of acute injury or joint degeneration.
• Running biomechanics are significantly altered following lower extremity amputation, necessitating careful consideration of loading patterns.