Physical Function, Gait, and Dynamic Balance of Transfemoral Amputees Using Two Mechanical Passive Prosthetic Knee Devices

Abstract

Lythgo N, Marmaras B, Connor H. Physical function, gait, and dynamic balance of transfemoral amputees using two mechanical passive prosthetic knee devices. Objective To investigate the effect of the 3R90 and 3R92 (Otto Bock Healthcare) mechanical passive prosthetic knee devices on the physical function, gait, and dynamic balance (sudden stop and turn) of transfemoral amputees. Design Intervention study with crossover design. Setting University research center. Participants Men (N=5; mean age ± SD, 58.8±11.9y) with unilateral transfemoral amputation. Intervention Prosthetic knee joints (N=2; 3R90 and 3R92). Acclimatization ranged from 14 to 47 days (25.5±9.3d). Main Outcome Measures Physical function, gait, dynamic balance. Results The Timed Up and Go Test, 6-Minute Walk Test, and Four Square Step Test measures improved with the 3R92. Total scores on the Prosthesis Evaluation Questionnaire were similar for the 3R92 (82.0±6.3) and the participant's own or original device (83.9±4.8). These devices were rated higher than the 3R90 (65.5±16.8). Compared with the original device, gait velocity was significantly slower (5cm/s; P=.017) with the 3R92, but was unchanged for the 3R90. This difference was not considered clinically significant because the effect size was small (0.2). No other significant gait differences were found. Large temporal gait asymmetries observed with the original device remained with the 3R90 and 3R92 (step, ≈20%; single support, ≈30%; stance, ≈19%). Although no significant differences were found for the sudden-turn or sudden-stop tasks, the sudden-turn group success rates were highest with the original devices. Conclusions Gait and symmetry measures were unchanged. Gait speed was slower with the 3R92, but this was not considered to be clinically significant. Sudden-turn success rates generally were higher with the original devices. A crossover stepping movement was more difficult to implement than a side-stepping movement during sudden turns.