Date of Award


Degree Name

Master of Science




Roger V. Gonzalez


Cost-effective lower-limb prostheses have been successful in restoring mobility, independence, and a way of life to millions of global amputees who do not have the means to afford more sophisticated prosthetics. Comprehensively, the current above knee (AK) prosthetic market is segmented into two extremes â?? very affordable relief style knees that offer basic functionality with high risk of accident due to falls, and very expensive styles that offer electronic microprocessor stumble control and adaptive cadence. There remains a gap for a middle-ground system that provides stumble control and greater stability within an achievable price bracket for the developing world. This project develops and tests a low-cost AK prosthetic with microprocessor stumble control.

The first phase of this study was the creation of the low-cost microprocessor knee using a combination of an existing polycentric four-bar relief knee and an Arduino-controlled hydraulic clamping mechanism. The system was created to mimic the natural motion and kinematics of a healthy limb by offering greater stability. The second phase was experimentally testing the prototype with patient trials, which compared walking and stumble control performance between the prototype, the polycentric four-bar LIMBS M3 knee, and the Ottobock C-Leg. Two patients were selected for the trials that involved walking across force plates to analyze ground reaction forces during gait and during a simulated stumble trial with the prototype knee.

The results of the patient trial concluded that the prototyped microprocessor solution was successful in adding stance stability and stumble control, while also offering natural gait comparable to the gold standard C-Leg. The conclusions of this work can be incorporated into future development of the prototype with the addition of dynamic cadence control and expanded patient trials comparing the low-cost solution to other currently available high-end systems.




Received from ProQuest

File Size

101 pages

File Format


Rights Holder

Lucas Jonathan Galey