Microprocessor Knee Research Articles

A Comparison of Energy Expenditure in People With Transfemoral Amputation Using Microprocessor and Nonmicroprocessor Knee Prostheses

A Comparison of Energy Expenditure in People With Transfemoral Amputation Using Microprocessor and Nonmicroprocessor Knee Prostheses

Balance, Balance Confidence, and Falls Using Nonmicroprocessor and Microprocessor Knee Prostheses

In Brief People with vascular leg amputations are typically older adults and are at a greater risk to fall, especially those with transfemoral amputation. Although balance confidence has been more predictive of prosthetic mobility than a simple history of falls, clinical measures of balance ability may provide a more objective assessment of fall risk. This case study documents balance ability, balance confidence, fall history, and activity participation in a person with transfemoral amputation due to vascular disease using 1) a non-microprocessor knee (MPK) prosthesis, 2) an MPK prosthesis after initial training, and 3) the MPK prosthesis after 1 year. The subject demonstrated higher balance ability measured with the Berg balance scale and timed-up-and-go test and higher Activity-specific Balance Confidence scale scores using the MPK prosthesis. The subject also did not fall and returned to participation in leisure activities using the MPK prosthesis. Although balance, balance confidence, and activity without falls improved in this case, future research is needed to identify and reduce causes of falls and to determine effect of different prostheses on balance in people with vascular transfemoral amputations, before making clinical conclusions. Although balance confidence has been more predictive of prosthetic mobility than a simple history of falls, clinical measures of balance ability may provide a more objective assessment of fall risk. This case study documents balance ability, balance confidence, fall history, and activity participation in a person with transfemoral amputation due to vascular disease using 1) a non-microprocessor knee (MPK) prosthesis, 2) an MPK prosthesis after initial training, and 3) the MPK prosthesis after 1 year. Although balance, balance confidence, and activity without falls improved in this case, future research is needed to identify and reduce causes of falls and to determine effect of different prostheses on balance in people with vascular transfemoral amputations before making clinical conclusions.

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

Hafner BJ, Willingham LL, Buell NC, Allyn KJ, Smith DG. Evaluation of function, performance, and preference as transfemoral amputees transition from mechanical to microprocessor control of the prosthetic knee. Objective To evaluate differences in function, performance, and preference between mechanical and microprocessor prosthetic knee control technologies. Design A-B-A-B reversal design. Setting Home, community, and laboratory environments. Participants Twenty-one unilateral, transfemoral amputees. Intervention Mechanical control prosthetic knee versus microprocessor control prosthetic knee (Otto Bock C-Leg). Main Outcome Measures Stair rating, hill rating and time, obstacle course time, divided attention task accuracy and time, Amputee Mobility Predictor score, step activity, Prosthesis Evaluation Questionnaire score, Medical Outcomes Study 36-Item Short-Form Health Survey score, self-reported frequency of stumbles and falls, and self-reported concentration required for ambulation. Results Stair descent score, hill descent time, and hill sound-side step length showed significant ( P<.01) improvement with the C-Leg. Users reported a significant ( P<.05) decrease in frequency of stumbles and falls, frustration with falling, and difficulty in multitasking while using the microprocessor knee. Subject satisfaction with the C-Leg was significantly ( P<.001) greater than the mechanical control prosthesis. Conclusions The study population showed improved performance when negotiating stairs and hills, reduced frequency of stumbling and falling, and a preference for the microprocessor control C-Leg as compared with the mechanical control prosthetic knee.

The Impact of C-Leg?? on the Physical and Psychological Adjustment to Transfemoral Amputation

ABSTRACT Amputation is a profound disruption to an individual's sense of self in the world. To understand the role C-Leg® (Otto Bock Health Care, Minneapolis, MN) can play in the physical and psychological adjustment of the transfemoral amputee, the authors employ a qualitative method of inquiry and analysis to supplement statistical data. Drawing upon earlier research, the authors discuss the meaning of lower-limb loss and restoration with a mechanical prosthesis in relation to the amputee's physical self, experiential world, and social relationships. The amputees reported being more aware of their body, having to plan and concentrate on most movements. Their physical surroundings assumed a different character as familiar objects took on different meanings in relation to their physical dysfunction. Subjects expressed a depreciative transformation in their relations with others, often feeling diminished and displaced—mere spectators to most events and activities. Replacing the mechanical knee with the C-Leg microprocessor knee improved mobility and function for amputees. However, to characterize the C-Leg only in this manner is to minimize its clinical significance. C-Leg's presence has the power to open up a world in which the amputee may re-establish and further develop his/her place and social standing. Because the C-Leg responds to the amputee's movement, it has the unique ability to be incorporated into the body; as such, both the C-Leg and the amputee's bodily self receded to the background of the individual's awareness. Attention was now directed toward the events, activities, and persons in the world around the amputee. Objects that were previously perceived as obstacles in an amputee's field of movement resumed to a significant degree their once familiar, pre-amputation character. In addition, the improved function and more natural, fluid gait allowed a re-integration and re-identification with able-bodied others.