Development of a Crutch Substitute for Mimicking Human Natural Walking Gait

Abstract

In order to resolve some of the disadvantages of conventional crutch designs, as well as some of the existing crutch-substitute devices, available on the market, a novel Exo-Limb crutch design is presented. The Exo-limb is a hands-free crutch meant to enhance and replace standard underarm crutches and other competitive products during injury rehabilitation. The focus of this research has been on creating a cost-effective passive device that mimics humans natural walking gait using purely mechanical components. Prior to the design, human natural treadmill walking was monitored by a 3D Motion Capture System and a reference end¢‚¬€œfoot trajectory with a ¢‚¬Ëœteardrop shape¢‚¬„¢ was acquired. Considering the design objectives, natural human walking and comfort, and other factors such as load capacity and weight of the device, the final design was determined. In order to satisfy the design objectives a kinematic synthesis, previously developed by one of the co-authors, is applied to test if the end¢‚¬€œfoot trajectory of the designed crutch substitute smoothly follows the desired reference, ¢‚¬Ëœteardrop shape¢‚¬„¢ in the vicinity of two specified task points, heel strike and toe off. A prototype of the final design was fabricated and its performance was tested by 2 mph treadmill walking. The research and developments made in this project with regard to mimicking the natural walking gait are important contributions that find applications in different areas, such as military, robotic locomotion, injury recovery and physical therapy.