The goal of the proposed research was to compare falls risk between microprocessor controlled prosthetic knee joints and non-microprocessor controlled prosthetic knee joints in older adults with unilateral transfemoral amputations. Microprocessor controlled prosthetic knee joints have been shown to improve certain aspects of gait in young adults, such as side to side symmetry, loading patterns, energy consumption, and risk of falling. However, no studies have examined older adults with unilateral transfemoral amputations to determine if the benefits of microprocessor controlled prosthetic knee joints apply to this high fall risk group. This knowledge is needed for health-care organizations to pay for these devices. A fall risk biomechanical analysis was performed using whole-body motion capture and ground reaction forces to compare non-microprocessor controlled and microprocessor controlled prosthetic knee joints while walking on a level surface, stairs, ramps, uneven terrain and during stumbling. Clinical information and self-reported risk of falls and near falls were also considered. This study was funded by The American Orthotic and Prosthetic Association in collaboration with Raymond G. Burdett, PhD (Co-Investigator) and Sara Peterson, PhD, CPO, FAAOP(D).