Physiotherapy - Theses
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ItemEvaluating the effect of self-management interventions on medial tibiofemoral contact force using electromyogram-informed neuromusculoskeletal modelling in people at risk of, and with, established knee osteoarthritis( 2022)Knee osteoarthritis (OA) predominantly involving the medial tibiofemoral compartment is a major public health problem worldwide causing pain, disability, and reduced quality of life. Longitudinal data suggest that higher knee loads during walking are associated with structural disease progression in people with medial knee OA. Higher knee loads during walking are also associated with structural disease onset in high-risk groups such as people who have undergone arthroscopic partial meniscectomy (APM). As there is no cure for OA, conservative interventions such as strengthening exercise and “appropriate” footwear are recommended throughout the OA disease continuum. However, no studies have been able to demonstrate that exercise can reduce knee loads in those at risk of, and with, established knee OA and belief that exercise could generate harmful knee loads continues to exist among patients and clinicians. This ambiguity also extends to footwear interventions, where stable supportive shoe types are recommended in most clinical guidelines despite conflicting biomechanical evidence that suggests flat flexible shoe types may reduce knee loads. A critical limitation of the current body of evidence is the use of the external knee adduction moment (KAM) as a surrogate measure of internal medial tibiofemoral contact force (MTCF). Change in the MTCF does not necessarily correspond directly with change in the KAM, predominantly due to the role internal muscle forces play in stabilizing the knee against these external loads. The use of electromyogram (EMG)-informed neuromusculoskeletal modelling is a promising means to consider the influence of muscle in estimates of internal contact force. However, it has not yet been implemented to estimate loads in knee OA intervention studies. The overarching aim of this thesis is to implement EMG-informed neuromusculoskeletal modelling to estimate MTCF during exercise and footwear interventions in people following APM (high-risk for developing knee OA), and those with established medial knee OA. This thesis first describes secondary analyses from two randomised controlled trials. In Study 1 (Chapter 4), which involved 41 participants aged between 30-50 years with medial APM in the prior 3-12 months, no significant difference in MTCF (peak and impulse) was found following a 12-week functional weightbearing exercise program compared to no intervention. In Study 2 (Chapter 5), which involved 62 participants aged over 50 with medial knee OA and varus malalignment, no significant difference in MTCF (peak or impulse) was found between a 12-week functional weightbearing (WB) and a 12-week non-weightbearing (NWB) quadriceps strengthening exercise program. Interestingly, the functional WB exercise program reduced the external contribution to MTCF, while the NWB quadriceps strengthening program reduced the muscle contribution to MTCF. This thesis then describes two cross-sectional studies, both utilising the same cohort of 28 people over the age of 50 with medial knee OA and varus malalignment. The first (Study 3, Chapter 6) compared the immediate effect of stable supportive and flat flexible shoes on continuous and discrete measures of MTCF during walking. Statistical parametric mapping (SPM) showed lower MTCF in the stable supportive compared to flat flexible shoes during 5-18% of stance phase. For the discrete outcomes, loading impulse, mean loading rate, and max loading rate were lower in stable supportive shoes compared to flat flexible shoes. The second cross-sectional study (Study 4, Chapter 7) evaluated the MTCF and muscle forces during each of three weightbearing exercises (double leg squat, forward lunge, and single-leg heel raise), relative to walking. Results showed that knee extensor and flexor force was higher during squatting and lunging compared to walking, while the MTCF was lower during squatting and heel raises compared to walking. Collectively, this thesis does not provide any evidence that 12-week functional weightbearing exercise programs can change MTCF in people following APM and with medial knee OA and varus malalignment. However, novel findings suggest that stable supportive shoes can reduce aspects of the MTCF compared to flat flexible shoes, suggesting that this shoe type may be most suitable for people with knee OA and varus malalignment. This thesis also provides evidence that common weightbearing exercises (squatting, lunging and heel raises) do not result in harmful increases in MTCF. These exercises may therefore be used safely in clinical settings for people with knee OA and varus malalignment.
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ItemFeasibility, safety and efficacy of dance for people with Parkinson's disease: a pilot study( 2013)The purpose of this thesis is to investigate the safety, feasibility and efficacy of dance for people with Parkinson’s disease (PD). Parkinson’s disease is a progressive neurological condition that is characterised by slow gait, reduced movement amplitude, tremor, rigidity, postural instability and diminished health-related quality of life (HRQOL). Physiotherapy and therapeutic exercise aimed at improving gait and balance are argued to be an important component in the management of PD and have been shown to improve gait function, mobility, balance and HRQOL in some individuals. Given the progressive and long term nature of the disease, it is important for people with PD to have access to a wide variety of exercise options so that they can remain active. Recent reports indicate that dance is emerging as an alternative to traditional exercise programs for people with PD, however there is little information regarding the safety and feasibility of dance interventions. A systematic review and critical appraisal was conducted with the aim of identifying studies that provide reports of safety, feasibility, intervention delivery and the efficacy of dance interventions for people with PD. The identified studies were of low to moderate methodological quality and design and the reporting of safety and feasibility outcomes was inconsistent. Whilst attrition was well reported, it was challenging to conclude the level of adherence and the occurrence of adverse events during dance classes due to limited reporting of these outcomes. The level of supervision provided, provision of instructor training and advice and the selection of music and movement choices was also not well reported. The results of a between-group synthesis of balance and mobility data showed a trend towards improvement in these outcomes following a dance intervention when compared to controls. These findings present limited evidence to support the efficacy of dance for people with PD. A group of nine Australians living with mild to moderate PD participated in a pilot case-series study to determine the safety, feasibility and efficacy of a six-week contemporary dance program. Safety and feasibility outcomes evaluated included the occurrence of adverse events, attrition, adherence and participant satisfaction. The effect of the dance program on gait function, functional mobility, balance, balance and gait self-efficacy and HRQOL was examined prior to the intervention, immediately post-intervention and at three months. The contemporary dance program was found to be a feasible and safe activity for people with PD in terms of attrition, adherence and adverse events. Attrition was low, with eight and seven participants completing follow-up assessments at post intervention and three-months respectively. Adherence was high with participants completing 78% of all available dance classes. Significant improvements in gait hypokinesia were observed immediately post-intervention compared to baseline measures and continued to improve three-months later. Significant improvements in functional mobility, relative to baseline were seen at post-intervention with a trend toward improvement noted at three-months. Despite improvements in gait function, there was little to no change observed for measures of balance, gait and balance self-efficacy and HRQOL. These results provide evidence to further support the safety and feasibility of dance for people with mild to moderate PD, and support the need for large randomized controlled trials to determine the efficacy and outcomes of dance therapy. Participant satisfaction is commonly regarded as an important component of quality health care and may influence the successful implementation of new interventions into clinical practice. Two focus groups were conducted after the pilot study with the purpose of gaining insight into the experiences and attitudes of the contemporary dance participants and to explore participant satisfaction within the context of feasibility. Thematic analysis revealed that participants were satisfied with the intervention and considered contemporary dance to be an acceptable form of exercise. The focus groups also revealed that the participants had a strong emotional reaction to the dance classes and identified several emotional, physical and cognitive benefits. This thesis has provided further knowledge to suggest that dance is a safe and feasible exercise alternative for some people with mild to moderate PD. Furthermore, this thesis has provided new evidence to support the efficacy of a short duration contemporary dance program to improve aspects of physical function and HRQOL. Although future work is needed, this research provides clinicians with evidence that supports the implementation of dance into clinical practice where it can benefit individuals living with Parkinson’s disease.
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ItemGait modification strategies for people with medial knee osteoarthritis( 2012)Knee osteoarthritis, most commonly occurring in the medial compartment, is a leading cause of pain and disability among the elderly. During gait, greater compressive load in the medial compartment is a major risk factor for osteoarthritis. As there is currently no cure, interventions which can reduce compressive loads are needed, because of their potential to slow disease progression. Evaluated during gait, the knee adduction moment is a commonly used surrogate measure of medial knee load and a marker for medial knee osteoarthritis progression. One of the conservative biomechanical approaches which may reduce the knee adduction moment is gait modification, or gait retraining. However, little is known about the strategies and their effects on medial knee load. Firstly, a systematic literature review was conducted to identify gait modifications. Of the 14 gait modifications identified in 24 studies, four strategies demonstrated greatest ability to reduce the knee adduction moment. Several limitations of previous studies were identified, such as poor reporting of methods, inclusion of participants without osteoarthritis, no evaluation of symptoms and limited information regarding the amount of modification required. Because of demonstrated ability to reduce a parameter of the knee adduction moment in cohorts, the following modifications were investigated in separate studies involving participants with symptomatic medial knee osteoarthritis: use of a cane on the contralateral side, increased lateral trunk lean and altered foot progression angle. The effects of contralateral cane use on knee load and pain were investigated in 23 individuals. Participants placed pre-determined magnitudes of support through the cane. Findings showed reductions in all knee load parameters, with a dose-response relationship. Likely due to biomechanical advantages, the technique of cane use influenced the load-reducing efficacy, such as cane positioning and timing of support. Whilst there were no changes in pain with cane use, individuals with greater severity of pain and varus malalignment reduced load more effectively. The effects of ipsilateral trunk lean gait on the knee adduction moment and pain were investigated in 22 individuals. Participants walked with varying magnitudes of trunk lean. Results demonstrated dose-response reductions in all knee load parameters, whilst pain remained unchanged. Timing of the gait modification mediated the efficacy of load reduction. Lastly, effects of altered foot progression angle on pain, the knee adduction and knee flexion moments were investigated in 22 individuals. Participants walked with varying degrees of toe-in and toe-out gait. Whilst pain remained unchanged, toe-in gait reduced the knee adduction moment during early stance but increased the knee flexion moment, knee adduction impulse and late stance adduction moment. Toe-out gait demonstrated opposite effects to toe-in gait. Furthermore, pain and malalignment demonstrated significant mediating effects for some outcomes. This thesis reports new and clinically relevant information on gait modifications for people with medial knee osteoarthritis. It was discovered that participant characteristics, the magnitude of modification and technique of performance altered the efficacy of load reduction achieved by gait modification strategies. Although future longitudinal evaluations are required, gait modifications investigated in this thesis may have potential to slow osteoarthritis progression via load reduction.