Comparison of Different Microprocessor Controlled Knee Joints on the Energy Consumption during Walking in Trans-Femoral Amputees: Intelligent Knee Prosthesis (IP) Versus C-Leg

The purpose of this study was to investigate the characteristic differences between the IP and C-Leg by making a comparative study of energy consumption and walking speeds in trans-femoral amputees. The subjects consisted of four persons with traumatic trans-femoral amputations aged 17 – 33 years who had been using the IP and were active in society. Fourteen able-bodied persons served as controls. First the energy consumption at walking speeds of 30, 50, 70, and 90 m/min was measured when using the IP. Then the knee joint was switched to the C-Leg. The same energy consumption measurement was taken once the subjects were accustomed to using the C-Leg. The most metabolically efficient walking speed was also determined. At a walking speed of 30 m/min using the IP and C-Leg, the oxygen rate (ml/kg/min) was, on average, 42.5% and 33.3% higher (P<0.05) than for the able-bodied group. At 50 m/min, the equivalent figures were 56.6% and 49.5% (P<0.05), while at 70 m/min the figures were 57.8% and 51.2% (P<0.05), a...