Gait stability and balance strategies of both acquired and congenital lower limb prosthetic users in response to perturbations

Alfatafta, Mahmoud

Thesis

Gait stability and balance strategies of both acquired and congenital lower limb prosthetic users in response to perturbations

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Creator

Alfatafta, Mahmoud

Rights statement

Strathclyde Thesis Copyright

Awarding institution

University of Strathclyde

Date of award

2021

Thesis identifier

T15907

Person Identifier (Local)

201753786

Qualification Level

Doctoral (Postgraduate)

Qualification Name

Doctor of Philosophy (PhD)

Department, School or Faculty

Department of Biomedical Engineering

Abstract

Falls are a health care problem for lower limb prosthetic users. The study of gait stability in lower limb prosthetic users facilitates improved insight and knowledge in different adaptation strategies of the human body in order to walk as functionally as possible with a prosthesis. The aim of this thesis was to determine how prosthetic users cope with unbalanced situations during walking and how these coping strategies may differ from able-bodied individuals. Improved understanding of such mechanisms may help reduce fall incidence. A number of prosthetic factors were considered including the use of a prosthetic foot incorporating an ankle joint, compared to a conventional prosthetic foot. Additionally, the effect of different alignments and the aetiology of the amputation or absence (congenital vs acquired amputation) was also considered. The study was conducted using an advanced dual-belt instrumented treadmill (CAREN). The protocol of perturbations in the study was adopted from a previous work by a group of researchers in University of Strathclyde (Roeles et al., 2018). Interventions used were anteroposterior (AP) perturbations by means of sudden changes in the walking speed to mimic a slip that can be faced in real-life situations. Main Outcome Measurements measured were AP and ML margins of stability (MoS) Hof et al. (2005). Step length, width and time were also measured to investigate the coping strategy following perturbation. Prosthetic users were less stable than able-bodied individuals. The involvement of the prosthetic side to recover stability was limited therefore, during rehabilitation stability training tasks for the intact side may help the prosthetic users enhance their overall stability and may reduce the fall incidence rate. Energy storing and return prosthetic feet may provide a sufficient level of stability compared to the feet which incorporate a moving ankle mechanism. The Ossur Pro-Flex foot demonstrated enhanced stability in the AP direction. Alignment changes from the optimal alignment may impose extra challenge to the stability. A short prosthesis was found to be the most challenging alignment change in response to perturbation. The prosthetic user with congenital related limb anomaly was found to be more stable than the prosthetic users with other lower limb loss. The outcomes of this study are novel and have potential to improve the understanding of how prosthetic users (acquired and congenital) react in when stability is compromised and the variables which may affect this further (foot design and alignment). It is envisaged that greater understanding of different adaptation strategies of the human body may help influence future prosthetic treatment, prescription, alignment and potentially component design.

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