Loading patterns in the intact limb of individuals with unilateral transtibial amputations and underpinning lower-limb joint mechanics

Abstract

Individuals with unilateral transtibial amputations (ITTAs) are at a greater risk of developing knee joint degenerative diseases in the intact limb compared to the general population. However, equivocal results from walking gait literature have found limited differences in load between the intact limb of ITTAs and control limbs. This thesis postulated that 1) data extraction of discrete points in loading signals are inconsistent; 2) other loading features, not previously considered, may more appropriately quantify load; and 3) overloading may be more prominent in tasks which have greater loading and joint movement demands. Therefore, this thesis aimed to determine if the intact limb of ITTAs had significantly different limb and knee joint loading patterns and underpinning mechanics compared to able-bodied controls during high loading activities. Eight ITTAs and twenty-two controls performed step descent and unilateral and bilateral drop landing tasks as experimental models to increase load. Loading waveforms were assessed using statistical parametric mapping as an alternative to discrete point analysis. Waveform analysis was able to identify loading rates (rather than peak magnitudes) as important measures of load and identify additional phases of interest when loading the limb. Anterior-posterior loading was also found to be an important feature in addition to the commonly examined loading features. The intact limb of ITTAs in this thesis was able to adapt to higher loading activities by adopting joint mechanics similar to controls despite reductions in quadriceps strength. Therefore, few differences were found in the whole-limb and knee joint loading patterns. This would suggest that high load in the intact limb compared to a control limb may not suggest an increased risk of knee joint degeneration but rather the asymmetry between prosthetic and intact limbs. Additionally, it is just as plausible to suggest that high limb loading is not the mechanism of injury in ITTAs.

Date of Award	12 Aug 2019
Original language	English
Awarding Institution	University of Roehampton
Supervisor	Siobhan Strike (Supervisor) & Neale Tillin (Supervisor)