Successful prosthetic fitting of elderly trans-femoral amputees with Intelligent Prosthesis (IP): a clinical pilot study.

The objective of the study was to compare the Physiological Cost Index (PCI) and walking speeds during walking in two elderly trans-femoral amputees when using knee joints which emphasized stance-phase control and Intelligent Prosthesis, and to provide some bibliographic observations on factors behind their success in improving walking ability despite their age. It was a within-subject comparison. The subjects comprised two patients, aged 75 and 81 years, with trans-femoral amputations. On admission subjects were subjected to one-leg cycling test driven by their non-amputated leg in order to evaluate their physical fitness. The PCI and speed during free level walking was measured using their original knee joints. The knee joint was then changed to IP and the subjects received prosthetic walking training programs using it. The PCI and speed measurements were taken during free level walking on completion of the training program. Both subjects showed a decreased PCI and an increased free walking speed when using the IP compared with the original knee joints. It was concluded that elderly trans-femoral amputees who are judged to be in good physical condition appear to merit the application of knee joints with superior swing phase control functions such as IP, regardless of their age.

Effect of physical fitness on prosthetic ambulation in elderly amputees.

OBJECTIVE: To evaluate the physical fitness and prosthetic ambulation ability of high-level (hip disarticulation, transfemoral) lower-limb amputees aged 60 and above, and to investigate the level of fitness required for successful prosthetic ambulation. DESIGN: The test subjects were 49 amputees aged 60 and above. Subjects were permitted to use any necessary ambulatory aids and were asked to walk at their most comfortable walking speed for evaluation of prosthetic ambulation ability. An incremental exercise test was performed to evaluate physical fitness. RESULTS: The average %VO(2max) value for the successful user group was 64.4%, and the average %VO(2max) value for the failed user group was 44.8%, a statistically significant difference (P < 0.01). Of the amputees with %VO(2max) > or =50, 93.7% were in the successful user group. Of the amputees with %VO(2max) <50, only 23.5% were in the successful user group. CONCLUSION: This study showed that the ability to sustain an exercise intensity of > or =50%VO(2max) can be regarded as a guideline value for the level of fitness required for successful prosthetic ambulation in elderly amputees.

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), and at 90m/min the figures were 61.9% and 55.2% (P<0.05%). Comparing the oxygen rates for the subjects using the IP and C-Leg at walking speeds of 30 m/min and 90 m/min it was found that subjects who used C-Leg walked somewhat more efficiently than those who used IP. However, there was no significant difference between the two types at each walking speed. It was also determined that the most energy-efficient walking speed for subjects using the IP and C-Leg was the same as for the controls. Although the subjects in this study walked with comparable speed and efficiency whether they used the IP or C-Leg, the subjects' energy consumption while walking with the IP and C-Leg at normal speeds were much lower than previously reported. This study suggested that the microprocessor controlled knee joints appeared to be valid alternative for improving walking performance of trans-femoral amputees.

Effect of an Intelligent Prosthesis (IP) on the walking ability of young transfemoral amputees: comparison of IP users with able-bodied people.

OBJECTIVE: To make a comparative study of energy expenditure and walking speeds between able-bodied people and young Intelligent Prosthesis (IP) users and to demonstrate the effect of IP on the walking ability of young amputees. DESIGN: The test subjects were eight young traumatic transfemoral amputees. Fourteen able-bodied persons served as controls. All amputees used an IP, and they had all undergone a prosthetic rehabilitation program for 8 wk. IP users, who had completed the rehabilitation program, were instructed to walk at speeds of 30, 50, 70, 90, and 110 m/min. Measurements of energy expenditure while walking were taken. The most metabolically efficient waking speed was also determined. RESULTS: On average, the IP users experienced an oxygen uptake that was 24.1% and 24.2% higher than those for the controls at speeds of 70 and 90 m/min, respectively. It was also determined that the most metabolically efficient walking speed for the IP users was the same as for the controls. CONCLUSIONS: This study showed that young IP users who undergo an adequate prosthetic rehabilitation program can achieve remarkably improved walking performance. Young IP users could walk at the normal speeds of able-bodied people, with only around a 24% increase in energy expenditure.

Physical fitness of lower limb amputees.

OBJECTIVE: To investigate the cardiorespiratory endurance of the physical fitness of amputees and able-bodied subjects of the same ages and to demonstrate deterioration of the physical fitness of the amputees. DESIGN: The test subjects were 31 amputees. Eighteen able-bodied persons served as controls. The incremental exercise test was performed to evaluate physical fitness. Sixteen of 31 amputees underwent endurance training by using a cycle ergometer driven by the intact leg, and their physical fitness was evaluated after completion of the endurance training program. RESULTS: The Vo2max, anaerobic threshold, and maximum workload for the amputees were significantly lower than those of the able-bodied group. The equivalent values for the endurance training group before exercise treatment were 18.0, 12.1, and 63.9, respectively. After exercise treatment, these values significantly increased, and there was no significant difference from the able-bodied subjects. CONCLUSIONS: This study showed that the physical fitness of amputees was clearly lower than that of the able-bodied subjects and that the amputees were able to recover from a poorly conditioned status after endurance training.