An outcome evaluation for two transfemoral prosthetic systems (a case study)

Pao Yue-kong Library Electronic Theses Database

An outcome evaluation for two transfemoral prosthetic systems (a case study)


Author: Wan, Kin-wah
Title: An outcome evaluation for two transfemoral prosthetic systems (a case study)
Degree: M.Sc.
Year: 2006
Subject: Hong Kong Polytechnic University -- Dissertations.
Amputees -- Rehabilitation.
Department: Dept. of Health Technology and Informatics
Pages: xv, 147 leaves : ill. (some col.) ; 31 cm.
Language: English
InnoPac Record:
Abstract: Transfemoral amputation is one of the most common amputations. The cause of limb loss may be due to trauma, infection, vascular disease, gangrene, diabetes, tumor or congenital deformity. In most transfemoral amputees, especially in the amputees with short residual limb, flexion and abduction deformities are inevitable. It is because part of the hip adductors and extensor muscles are removed during amputation. As a result, there are no sufficient muscles fibers and long lever arm to generate efficient power to control prosthesis during walking. Hence, transfemoral amputees require more effort and higher energy expenditure for walking, which is 65% above normal subject for level walking. Furthermore, amputees readily have negative body image because of the change of appearance, asymmetric walking posture, poor sensation and proprioception. As a result, they are not willing to participate in social activities or sports. Moreover, the prosthesis may increase the social burden for the amputees. For the recent decade, most companies have designed various types of the transfemoral prosthesis in an attempt to give the amputees a more natural gait pattern and less energy expenditure during walking. There are many different prosthetic knee joints and feet for amputees to apply on their prostheses. Some studies showed that multi-axis prosthetic knee joints and prosthetic feet could help the amputees to carry out different activities with a good performance and reduce the energy consumption. However, most previous studies focused on either the prosthetic knee joints or prosthetic feet and limited studies were on the overall performance of the whole transfemoral prosthetic system at the same time. On the other hand, most of the studies carried out in the gait laboratory and the outdoor activities were not included. Therefore, the aim of this study was to evaluate the performance of two commonly used prosthetic systems namely OS (7-bar polycentric knee joint with hydraulic swing phase control and carbon fiber energy storing prosthetic foot), and OB (single axis knee joint with spring extension assist and solid-ankle-cushion-heel) via subjective and objective assessment methods. One subject was invited to participate in this study. A subjective measurement, Prosthesis Evaluation Questionnaire (PEQ) and two objective measurements, Step Activity Monitor (SAM) and Human Motion Analysis System were used to gather different clinical parameters for analyses. The result of SAM showed that the amputee was a daytime walker and differences in some activity levels were found between the two systems. The total number of steps in OS system was more than that of the OB system. Moreover, a better walking performance was showed in the OS system. For example, more walking steps belonged to the higher cadence category was found in the studied period. Moreover, the utility scale of the PEQ showed that the subject preferred the OS system to the OB system, and the sounds scale of the PEQ reflected that the OS system had fewer disturbances during walking. In the human locomotion analyses, the kinematic and kinetic data for both systems were similar. The stance phase tended to be shorter while the swing phase was longer in amputated limb for both systems as compared with the sound limb. In general, the OB system is recommended to the transfemoral amputees with moderate activity level while the OB system is suitable for the transfemoral amputees with low activity level. For the future study, the data collection period should be extended to two-year long as more information can be gathered for analysis.

Files in this item

Files Size Format
b20902402.pdf 15.80Mb PDF
Copyright Undertaking
As a bona fide Library user, I declare that:
  1. I will abide by the rules and legal ordinances governing copyright regarding the use of the Database.
  2. I will use the Database for the purpose of my research or private study only and not for circulation or further reproduction or any other purpose.
  3. I agree to indemnify and hold the University harmless from and against any loss, damage, cost, liability or expenses arising from copyright infringement or unauthorized usage.
By downloading any item(s) listed above, you acknowledge that you have read and understood the copyright undertaking as stated above, and agree to be bound by all of its terms.


Quick Search


More Information