Gait Simulation & Prosthetic Foot Testing

© Fraunhofer IPA
Test setup for foot prostheses

In Short

Quantification of mechanical properties of body worn products, such as prostheses, orthoses, footwear. Mechanical tests on prosthetic feet according to ISO 22675 under defined load conditions to evaluate static strength and durability during cyclic loads on the heel and forefoot. Functional properties quantified according to ISO 16955.

In Detail

Background:

International standardized test methods are used to determine the strength of foot prostheses, which play an essential role in the evaluation of product safety and approval according to MDR. To assess the conformity of prosthetic feet, a mechanical strength and durability test based on several million cycles must be carried out according to ISO 10328 or ISO 22675 under defined load conditions. In addition to safety-related strength tests, functional properties can also be measured in accordance with ISO 16955. The load conditions experienced during the entire stance phase can be dynamically simulated, from the moment the heel touches the ground to when the toes leave the ground. Additionally, individual isolated movements can be performed to analyze effects in detail.

 

Testing equipment:

A hydraulically driven machine (Shore Western KS2-07) is used to test prosthetic feet according to ISO 22675. The machine has two separately controlled actuators: a rotating platform that follows the lower angle of the leg in the sagittal plane, and a linear actuator that applies a dynamic load to the prosthetic foot in a synchronized motion during the stance phase. Load characteristics can be modified according to the customer-specific load conditions (ground reaction forces during walking, running, etc.). The high reproducibility and repeatability of this test method allow a standardized comparison of the test samples.