Mechanical & Materials Engineering, Department of


First Advisor

Carl A. Nelson

Date of this Version



Elley, Devin K, "Application of DFX Methods to a Gait Rehabilitation System" (2017). Master thesis collection for the University of Nebraska-Lincoln.


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska In Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Mechanical Engineering and Applied Mechanics, Under the Supervision of Professor Carl A. Nelson. Lincoln, Nebraska: July, 2017

Copyright (c) 2017 Devin K. Elley


Walking is an important physical activity that offers major health benefits for those who are able to perform the task. However, there are millions of people worldwide who have lost the ability to walk from physical accidents or a disease which limits the ability for them to use their legs. Often these patients use gait therapy to learn how to walk again. During this gait therapy, a physical therapist may use gait rehabilitation machines to assist the patient in learning to walk in a correct gait path.

Two gait rehabilitation machine iterations were designed to produce an effective rehabilitation machine that could be used for both pediatric and adult use. The second iteration was designed based on the failures of the first design. The goal was to design a machine that is adjustable between pediatric and adult patients and to be cost effective for small clinics and in-home patient use. Design for Manufacture (DFM) and Design for Assembly (DFA) are two tools that can be applied to a product during the design stage of the products life to ensure the product is designed to be cost efficient. However, when the aforementioned designs were made, DFM and DFA principles were not fully applied in the design stage and possible advantages of using them were missed during the design and production of the two rehabilitation machines.

The goal of this study is to show the potential advantages of applying DFM and DFA into the design process through the comparison of a DFM/DFA analysis of the gait rehabilitative device iterations. After a DFM/DFA analysis was made of both design iterations it was found that there was a 40.04% cost reduction in manufacturing and assembling of Design 2 as compared to Design 1. Therefore, it was concluded that Design 2 was a more cost effective design than Design 1. This study also highlights areas for improvement in the current design iteration.

Advisor: Carl A. Nelson