title: Amputee Subject Testing Protocol, Results, and Analysis of a Powered Transtibial Prosthetic Device.
abstract: A powered ankle-foot prothesis and its control system were previously designed and built. To evaluate this prosthesis, amputee subject testing was performed. The testing results are analyzed and compared between the powered prosthesis, passive prosthesis, and able-bodied gait. Qualitative comparison showed the prosthesis achieved the design objectives. During stance phase, active ankle moment was generated in the powered prosthesis before push-off to help the amputee walk more naturally. During swing phase, the powered prosthesis was able to move to natural position to achieve foot clearance. However, the prosthesis is slightly under powered compared with the able-bodied ankle.
authors.affiliation: Department of Mechanical Engineering, Marquette University , Milwaukee, WI 53233 e-mail:  jinming.sun@marquette.edu.
authors.forename: Jinming
authors.initials: J
authors.lastname: Sun
authors.affiliation: Department of Biomedical Engineering, Marquette University , Milwaukee, WI 53233 e-mail:  jessica.fritz@marquette.edu.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Fritz
authors.affiliation: Department of Physical Medicine and Rehabilitation, Medical College of Wisconsin , Milwaukee, WI 53226 e-mail:  ddeltoro@mcw.edu.
authors.forename: David R
authors.initials: DR
authors.lastname: Del Toro
authors.affiliation: Department of Mechanical Engineering, Marquette University , Milwaukee, WI 53233 e-mail:  philip.voglewede@marquette.edu.
authors.forename: Philip A
authors.initials: PA
authors.lastname: Voglewede