http://opmarketing.com/storage/Research%20EncyclOPedia/Microprocessor%20Knees/Hafner-%20APMR%202007.pdf

Evaluation of Function, Performance, and Preference as Transfemoral Amputees Transition From Mechanical to Microprocessor Control of the Prosthetic Knee

Biomechanics and physiological parameters during gait in lower-limb amputees: a systematic review

https://www.archives-pmr.org/article/S0003-9993(10)00008-0/pdf

Comparative Biomechanical Analysis of Current Microprocessor-Controlled Prosthetic Knee Joints

The functional differences between persons with amputation who are classified as Medicare Functional Classification Level (MFCL)-2 and -3 include the abilities to walk at various cadences and to negotiate environmental barriers outside the home. This study compared the effect of active microprocessor control and passive mechanical control of the prosthetic knee on function and safety in 17 subjects with transfemoral amputation (8 MFCL-2 and 9 MFCL-3). Assessed functional tasks included hill and stair descent, an attentional demand task, and an obstacle course. Self-reported measures included concentration, multitasking ability, and numbers of stumbles and falls. Active knee control was associated with significant improvements (p < 0.05) in hill and stair gait, speed (hills, obstacle course, and attentional demand task), and ability to multitask while walking for both cohorts. MFCL-2 subjects also reported a significant reduction (p < 0.01) in uncontrolled falls. Over the study, 50% of MFCL-2 subjects and 33% of MFCL-3 subjects transitioned to a higher MFCL. Results suggest that active knee control improves function and reduces the frequency of adverse events in a population that is at risk for falls. Use of active knee control may allow persons with amputation to expand their functional domain, transition to a higher MFCL, and access additional prosthetic options.

/pdf/differences-in-function-and-safety-between-medicare-3uspcvrida.pdf

Differences in function and safety between Medicare Functional Classification Level-2 and -3 transfemoral amputees and influence of prosthetic knee joint control

Energy expenditure and activity of transfemoral amputees using mechanical and microprocessor-controlled prosthetic knees.

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.

Comparison of different microprocessor controlled knee joints on the energy consumption during walking in trans-femoral amputees: intelligent knee prosthesis (IP) versus C-leg.

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.

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

Objective: To investigate the differences in energy consumption by patients with hip disarticulation between prosthetic walking and wheelchair locomotion. Design: The subjects consisted of seven amputees, all older than 60, with unilateral hip disarticulation. Energy consumption when walking with prosthesis and when propelling a wheelchair, each at the respective comfortable movement speed, was measured by means of a portable telemetric system. Results: The average comfortable movement speed for prosthetic walking was 30.5 m/min, which was much slower than the 63.1 m/min average for wheelchair locomotion (P < 0.01). The average oxygen cost value for prosthetic walking was 0.639 ml/kg/m, and the average for wheelchair locomotion was 0.1 75 ml/kg/m, indicating that oxygen cost was significantly higher for prosthetic walking than for wheelchair locomotion (P < 0.01). Conclusions: The results of this research clearly showed that the efficiency of prosthetic walking for elderly hip disarticulation amputees was very low. When the subject is judged not to be a candidate for practical prosthetic walking after a careful multidisciplinary evaluation, wheelchair locomotion may be an alternative to prosthetic walking as a realistic goal.

Energy consumption during prosthetic walking and wheelchair locomotion by elderly hip disarticulation amputees.

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 u...

Katsuhiro Machida

Papers

Comparison of different microprocessor controlled knee joints on the energy consumption during walking in trans-femoral amputees: intelligent knee prosthesis (IP) versus C-leg.

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

Energy consumption during prosthetic walking and wheelchair locomotion by elderly hip disarticulation amputees.

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