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Logo for the Journal of Rehab R&D
Volume 41 Number 5, September/October 2004
Pages 675  — 682


Biomechanical and clinical evaluation of a newly designed polycentric knee of transfemoral prosthesis

Kazutoshi Yokogushi, PhD; Hiroshi Narita, PhD; Eiichi Uchiyama, PhD; Susumu Chiba, PhD;
Toshiya Nosaka, PhD; Ken-ichi Yamakoshi, Prof PhD

Division of Rehabilitation, Sapporo Medical University Hospital, Sapporo, Japan; Department of Neurology, Sapporo Medical University, Sapporo, Japan; Graduate School of Natural Science and Technology, Kanazawa University,
Ishikawa, Japan
Abstract — We have designed a new polycentric knee adopting a hydraulic unit and an intelligent mechanism. The biomechanical parameters of this prototype, such as the stance duration, peak knee flexion angle in stance and swing, peak hip flexion angle, and peak hip extension moments were analyzed at three different cadences (88, 96, 104 steps/min) in three amputees, and then compared to those of polycentric hydraulic knees currently in use. The same parameters were also measured for 10 healthy volunteers and subsequently analyzed. In the prototype, almost all the values of the parameters showed no significant variety in individuals at the different cadences. The situation was the same with the healthy volunteers. However, the values of the parameter for the conventional knee varied significantly with the individual at the different cadences. The prototype may be of practical use, contributing to a stable walk even at different cadences.
Key words: biomechanics, hydraulic, knee joint, pneumatic, polycentric, prototype, transfemoral prosthesis.

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