A prosthesis-specific multi-link segment model of lower-limb amputee sprinting.

Area of Science:

• Biomechanics
• Prosthetics
• Gait Analysis

Background:

• Lower-limb amputees often use energy storage and return (ESAR) prostheses for sprinting.
• Conventional gait analysis models for these prostheses often oversimplify their structure, lacking an articulating ankle.

Purpose of the Study:

• To investigate how different link segment models and marker sets affect the calculated kinematics, kinetics, and energetics of unilateral amputee sprinters.
• To determine the necessity of prosthesis-specific modeling in gait analysis.

Main Methods:

• Developed five distinct lower-limb prosthesis models, including conventional and hybrid designs, and a six-segment Multi-link Segment (MLS) model.
• Utilized the Plug-in-Gait (PiG) marker-set and a custom marker-set for prosthesis-specific geometry.
• Performed full-body musculoskeletal modeling and simulation using OpenSim 3.2 with experimental marker trajectories.

Main Results:

• Prosthesis model geometry significantly affected all calculated gait variables for the affected leg (p < 0.05).
• The marker-set also significantly influenced all affected leg variables, but not the unaffected leg.
• Omission of prosthesis-specific properties led to significant alterations in calculated amputee gait characteristics.

Conclusions:

• The geometry and marker-set of the lower-limb prosthesis model critically influence gait analysis outcomes for amputee sprinters.
• A Multi-link Segment (MLS) model, incorporating prosthesis-specific properties, is recommended for accurate amputee gait analysis.