Physiotherapy - Theses

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    Evaluating 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
    Starkey, Scott Christopher ( 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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    Gait and functional ambulation in children and adolescents with Charcot-Marie-Tooth disease
    Kennedy, Rachel Alexandra ( 2018)
    Children and adolescents (“children”) with Charcot-Marie-Tooth disease (CMT) have progressive weakness of the lower limbs causing problems with gait and function. This thesis examined the nature and impact of gait dysfunction in children with CMT, with consideration of the typical everyday environments in which children function. Little is known about the effect of this degenerative peripheral neuropathy on gait and functional ambulation over time in children. Gait dysfunction may contribute to retrospective reports of frequent trips and falls in children with CMT, yet there are no studies of falls in this population. Children with CMT often report reduced physical endurance, yet no studies have investigated physical endurance, and more generally functional ambulation and physical activity. Six studies were designed to address these knowledge gaps, with comparison to typically developing peers (TD) to place gait dysfunction within the context of typical growth and development. A systematic review of gait in paediatric CMT found only a few studies with small sample sizes, examining barefoot gait in clinical and laboratory settings and providing limited comparison to TD databases. Gait was slower, most likely due to shorter stride length, with foot drop, reduced calf push-off power and proximal lower limb compensatory strategies. Two cross-sectional, case controlled studies utilising spatio-temporal gait analysis, one in different footwear and the other during a six-minute walk test, confirmed that gait in 30 children with CMT was slower, with shorter and wider steps, and greater step-to-step variability compared to TD children. Increased barefoot base of support variability was associated with poorer balance. Suboptimal footwear negatively affected gait in all children, irrespective of disease, which has clinical implications for children with CMT who have weak feet and ankles and poor balance. Reduced six-minute walk distance (6MWD) was an indicator of reduced physical endurance, and increased step-to-step variability was moderately associated with reduced 6MWD and increased perceived exertion. A longitudinal study of gait in 27 children with CMT over 12-months highlighted the importance of normalising gait data in children. Over 12-months, children with CMT were found to have reduced walking speed and endurance, and older children (≥ 12 years) exhibited greater disease progression and decline in functional ambulatory capacity than younger children. A novel six-month prospective cohort study of falls identified a markedly higher incidence of falls in children with CMT, with concerningly high numbers of injurious falls compared to TD children. Tripping was the most common mechanism of falls and all children under the age of 7 years fell, irrespective of disease. Age and balance were the strongest predictors of falls. A cross-sectional, case controlled study of functional ambulation and physical activity in 50 children with CMT across two paediatric centres found that functional ambulation was limited on all measures, including capacity, performance in every day environments, and the child’s perception of gait-related disease limitations. Children with CMT were less physically active than their TD peers with greater disease severity associated with lower physical activity. This thesis delivers important information to healthcare providers and families of children with CMT, and highlights the degree to which gait dysfunction impacts everyday activities. Gait dysfunction can be used as a biomarker of disease severity and progression in CMT. These findings will inform management of children with CMT, development of clinical practice guidelines and educational resources, and influence future research, including exercise interventions.
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    Post-traumatic knee osteoarthritis after anterior cruciate ligament reconstruction: Psychological, functional and biomechanical factors and the effect of a targeted brace
    HART, HARVI ( 2015)
    Post-traumatic knee osteoarthritis (OA) after anterior cruciate ligament reconstruction (ACLR) is prevalent in younger adults and has the potential to cause substantial knee-related symptoms and limit physical function. Physical and psychological impairments are likely to adversely affect quality of life and work participation. Knowledge of modifiable risk factors associated with knee OA post-ACLR has the greatest capacity to lead to new interventions that could change the natural history of knee OA. What are the modifiable factors associated with knee OA post-ACLR? Section A of this thesis describes the results of two cross-sectional studies which revealed that individuals with knee OA five to 12 years post-ACLR have worse knee confidence and greater kinesiophobia compared with individuals who have no OA five to 12 years post-ACLR. In individuals with knee OA five to 20 years post-ACLR, those with worse knee confidence have worse knee-related symptoms, poorer function, greater kinesiophobia, and poorer perceived self-efficacy and health-related quality of life. Section B of this thesis investigated knee biomechanics during walking in individuals post-ACLR. Pooled data from a systematic review revealed that, compared to healthy controls and uninjured contralateral knees, ACLR knees have abnormal knee biomechanics, particularly in the sagittal plane. Systematic review findings also revealed that the type of graft (hamstring or patellar) and time post-surgery could also influence knee biomechanics. A cross-sectional study also evaluated biomechanics in people with lateral knee OA post-ACLR. Compared to healthy controls, individuals with lateral knee OA five to 20 years post-ACLR had greater knee flexion and lower knee internal rotation angles, as well as greater pelvic anterior tilt, and hip flexion angles. Is there a potential intervention for modifiable risk factors associated with knee OA post-ACLR? A targeted knee brace was investigated for individuals with knee OA post-ACLR. First, a within-subject randomized study investigated the immediate and four-week effects of a targeted knee brace on knee-related symptoms and function in individuals with knee OA post-ACLR. The brace produced improvements in knee-related symptoms immediately and following four weeks of intervention. Second, a within-subject randomized study evaluated the immediate effects of varus bracing on gait characteristics in individuals with lateral knee OA post-ACLR. Results revealed that the unloader brace significantly altered gait characteristics associated with lateral knee OA post-ACLR. Overall, this thesis sheds light on some of the modifiable risk factors associated with knee OA post-ACLR, and investigated one targeted intervention with the potential to improve quality of life of individuals with knee OA post-ACLR. Targeting psychological, functional and biomechanical risk factors in individuals post-ACLR may aid in optimal recovery, and slowing disease progression in individuals with knee OA post-ACLR.
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    Feasibility, safety and efficacy of dance for people with Parkinson's disease: a pilot study
    Twyerould, Rebecca Louise ( 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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    Mobility characteristics in children with hereditary spastic paraplegia
    ADAIR, BROOKE ( 2013)
    The aim of this thesis was to investigate characteristic deviations in mobility and gait in children with hereditary spastic paraplegia (HSP). Hereditary spastic paraplegia is a neurodegenerative condition which is most commonly associated with limitations in functional mobility and gait dysfunction. Little quantitative information has been published describing the common mobility and gait deficits in children with HSP. The previous literature has not addressed the best measurement tools to quantify mobility nor has it provided objective evidence for changes in functional mobility over time in children with this condition. Although a small number of studies exist describing the kinematic gait deficits of children with HSP, results are limited to the sagittal plane of movement. A better understanding of the mobility and gait characteristics that are unique to this population would enable physiotherapists to provide a more holistic service to children and families with HSP. A greater depth of knowledge could help clinicians to develop more accurate hypotheses of the causative factors in gait and mobility disturbances, thereby facilitating the prioritisation of treatment techniques towards the most affected areas. A systematic literature review identified and critically evaluated outcome measures to quantify functional mobility in children with HSP. Evidence regarding the psychometric properties of functional mobility measures in this population was found to be limited. Three measurement tools were identified that clinicians may consider when assessing mobility in children with this condition. The outcome measures were the Gillette Functional Assessment Questionnaire, the Functional Mobility Scale and the Gross Motor Function Measures. The Functional Assessment Questionnaire and the Functional Mobility Scale were incorporated into three subsequent studies. A longitudinal study of retrospective data documented changes in functional mobility over time. Thirty children with HSP were assessed over an average of four years. Contrary to beliefs, analysis of functional mobility levels for the entire cohort demonstrated minimal changes over the period of assessment. Functional mobility over longer distances exhibited statistically significant improvements (p < .001). Functional mobility in the school environment was the only exception, with more children demonstrating a tendency towards deterioration over time. In general, the results indicate that not all children with HSP deteriorate in functional mobility over time. An analysis of retrospective kinematic gait data from 17 children with HSP confirmed that gait deviations existed in all three planes of movement when compared with the gait kinematics of unimpaired children. Overall, the deficits in the sagittal plane concurred with the previously published literature for children with HSP. The coronal plane revealed previously unreported kinematic gait deviations, including a reversal of the usual pattern of pelvic obliquity. These results confirm that kinematic deficits exist in all three planes of movement in children with HSP. Given the deviations at the proximal joints, further research is also warranted to describe the deficits at the trunk in children with this condition. A prospective study focussed on describing the kinematic deviations at the trunk, pelvis and hips in 11 children with HSP. Movements of the trunk and pelvis were found to be particularly compromised in the sagittal and coronal planes. These segments demonstrated larger amplitudes and subsequent increases in the ranges of movement. Although pelvic rotation showed little deviation when compared to unimpaired children, increased amplitudes of pelvic rotation were strongly associated with higher levels of functional mobility. These findings indicate that the trunk can be affected in some children with HSP. Further research is necessary to determine the cause of trunk and lower limb deficits in children with HSP. This thesis is the first to provide an in-depth analysis of mobility in children with HSP. Outcome measures were identified that can be utilised by physiotherapists when assessing children with this condition. The findings regarding mobility and gait characteristics in children with HSP are likely to assist physiotherapists and other health professionals to focus clinical assessments towards the most affected segments and planes. This information forms a foundation for future studies of mobility in HSP. In particular, the findings indicate the need for further investigations of longitudinal changes in mobility and the effectiveness of physiotherapy techniques in children with HSP. Ultimately, this new knowledge may help to improve the education of children and families with HSP, prioritise physiotherapy treatment plans and enable the best possible outcomes in children with this complex, neurological condition.
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    Gait modification strategies for people with medial knee osteoarthritis
    SIMIC, MILENA ( 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.
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    Aging modifies joint power and work when gait speeds are matched
    Cofré Lizama, Luis Eduardo ( 2010)
    It is well known that ankle joint power generation is reduced in healthy older adults during gait. No general consensus exists, however, as to what fundamental or core compensatory actions are made at the knee and hip joints by the older adults to compensate for this loss in ankle joint power. The failure to control, and the relatively high variability, in gait speed may account for this lack of agreement. This study investigated the effect of aging on lower limb joint power and mechanical work during gait. The gait patterns of twelve old (66.8 ± 4.5 yr) and 12 young adults (26.6 ± 2.9 yr) were recorded for a range of matched (1.0 m•s-1, 1.3 m•s-1, 1.6 m•s-1) and self-selected speeds. Matched speeds did not differ between the groups. Combining matched speeds, the older adults generated 14% less A2 power and mechanical work (p<0.05). Compared to the young adults, the older adults produced 45% more H2 peak power, 7% more H3 peak power, 35% more K3 peak power and 11% more K4 peak power (p<0.05). No significant H1 power and mechanical work differences were found. The older adults also exhibited less ankle plantar flexion, more hip flexion and anterior pelvic tilt (p<0.05). At the 1.6 m•s-1 speed the older adults adopted a different gait pattern compared to young adults, generating more H3 than A2 mechanical work. This shows that the older adults rely more on hip flexors to propel the leg into swing when ankle plantar flexor function is reduced. This may partly explain how gait dysfunctions emerge with aging.
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    People with Parkinson's disease should avoid performing dual-tasks while walking: myth or reality?
    Fok, Pamela Ching Kwan ( 2009)
    Traditionally, people with Parkinson’s disease (PD) are advised to avoid performing dual-tasks while walking. Rehabilitation programs also emphasise the need to train walking under single-task conditions to improve gait and reduce risk for falls. There are findings that people with PD can walk faster and with longer strides while performing a secondary motor or cognitive task, when cued by a metronome or visual floor stripes. There are also findings that people with PD can walk faster and with longer strides while performing a secondary motor task simply by prioritising their attention to take big steps. Using attention is a convenient strategy favoured by people with PD to manage their gait difficulties. This thesis examined the immediate and training effects of two attention-priority strategies on dual-cognitive task walking in people with mild to moderate PD. Two groups of participants received 30 minutes of training to prioritise attention to take big steps while performing serial three subtractions (gait-priority strategy) or to divide their attention between taking big steps and the cognitive task (equal-priority strategy). Control groups received no training. Measures of gait hypo-bradykinesia (stride length and gait velocity), stride variability (Coefficient of variation [CV] of stride length and CV of stride time) and cognitive task performance (accurate enumeration rate) were assessed at baseline, during training, immediately after training and 30 minutes after training. Both attention-priority strategies improved stride length and gait velocity during training. The improvement was retained for at least 30 minutes after training. Both strategies have no effect on CVs of stride length, stride time and accurate enumeration rate. Many daily routines require our ability to overcome single-, dual- and multi-task demands while walking. Rehabilitation strategies should encompass real life demands in order to minimise functional impairments, activity limitations and participation restrictions, as recommended by the World Health Organisation. Putting together the findings of this thesis and the evidence provided by previous studies, it is concluded that traditional recommendations need qualification. Avoiding dual-tasks during walking or gait retraining in people with mild to moderate PD may not be necessary. Gait-priority and equal-priority strategies can be used as compensatory strategies to improve gait during dual-tasks. The two strategies can also be used in training programs for walking rehabilitation.