Main author: Christophe Lecomte
Institution or Company: Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, University of Iceland, Össur Inc.
Co-Authors, Institution or Company:
Anna Lára Ármannsdóttir, Department of Physical Therapy – Research Centre of Movement Science, Faculty of Medicine, University of Iceland, Össur Inc. Kristín Briem, Department of Physical Therapy – Research Centre of Movement Science, Faculty of Medicine, University of Iceland. Sigurður Brynjólfsson, Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, University of Iceland.
Introduction: State of the art biomechanical analysis of amputee gait for level ground, ascending and descending ramp walking, was compared to a mechanical test bench simulating each task. We hypothesize that an advanced mechanical test method can be used to evaluate prosthetic foot stiffness and will be comparable to state-of-the-art biomechanical analysis of amputee gait for all tasks. This dynamic testing can lower the burden of user testing.
Method: Five users were enrolled in the biomechanical data collection comparing the angular stiffness properties of the prototype. The users walked at three different speeds during level ground data collection but at one speed during ramp ascent/descent. The test was performed on an instrumented dual belt treadmill and a 3D motion capture system used to measure body kinematics.
Result: For level ground walking we found a strong correlation for the ankle moment and ankle angle results during dorsiflexion. Plantarflexion angle was larger on the machine than measured on users. For ramp ascent, the maximum dorsiflexion prosthetic foot angles are comparable but the plantarflexion angles are lower for the biomechanical data versus the test bench. During ramp descent, a large difference between our two test methods was seen
Discussion: The output measurements from the test bench used in conjunction with the camera provides a good comparison to the state-of-the-art biomechanical data generally provided using gait analysis. The dynamic testing allows researchers and prosthetic foot designers to evaluate devices properties on a test bench. This dynamic testing can lower the burden of subject testing.
