The effects of prosthetic alignment on gait biomechanics

In clinical settings, trans-tibial prosthetic alignment is a primarily subjective procedurethat is based on: the clinical experience and judgment of prosthetists; and amputeefeedback regarding comfort, stability and performance, which can be unreliable. Thishighlights the need for a more objective understanding of prosthetic alignment whichwould lead to better guidance and tools for prosthetists to assess and modify prostheticalignment; thus facilitating comfortable ambulation, aesthetic gait appearance, and lowenergy cost of walking for amputees 7 ' 16 ' 25 .Previous research studies have the advantage of presenting objective and quantitativeknowledge which cannot be obtained from subjective observations. However, most ofthese studies have only considered the relationships between fairly limited sets ofbiomechanical characteristics and prosthetic alignment settings. Furthermore, amputeecomfort has not usually been addressed within the same studies. Therefore, the studyreported in this thesis considers the effects of alignment changes on both biomechanicalmeasures and comfort. The goals of the study were: 1) to investigate the effects ofalignment changes on the kinematics and kinetics of trans-tibial amputee gait; and 2) toassess the feasibility of a new objective approach for predicting amputee comfort bymeasuring both the forces and moments at the socket/pylon interface using inversedynamics calculations based on captured kinematic and kinetic data.Because this pilot study involved only one subject, the findings should be treated withcaution. However, it is possible to make tentative conclusions with regard to possibleobjective alignment criteria. For example, based on the results, socket flexion versusextension appears to involve a trade-off between: a) achieving foot flat effectivelywhilst maintaining a good first GRF peak (not too extended); b) providing sufficientdorsi-flexion resistance during single stance (not too flexed); c) providing sufficientpush-off (not too flexed); and d) avoiding pelvis obliquity (not too extended).Interestingly, it appears possible to make these judgments with just a force-plate and acoronal plane observation of obliquity.

Level dc:type.qualificationlevel

Master's Level (Level 7)

Year dc:date.issued

2010

Author dc:creator

• Malaheem, MSM

Language dc:language

en

Identifier

oai:salford-repository.worktribe.com:1337062

OAI identifier oai:identifier

oai:salford-repository.worktribe.com:1337062