Christopher Barr

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SUMMARY The cells of Voronoi diagrams generated by epicentral locations of Southern California earthquakes are inspected. The tapered Pareto distribution is shown to fit quite well to the distribution of cell areas and perimeters. This same distribution, which has been used to model the distribution of seismic moments, is also a close approximation to the(More)
BACKGROUND The aims of this study were 1) to examine postural sway in the eyes open (EO) and eyes closed (EC) conditions in people with multiple sclerosis (MS) with moderate levels of disability compared with controls and 2) to examine relationships between postural sway and total Expanded Disability Status Scale (EDSS) scores, functional system subscores,(More)
OBJECTIVE To determine whether normalizing spatial-temporal gait data for walking speed obtained from multiple walking trials leads to differences in gait variability parameters associated with a history of falling in people with transtibial amputations. DESIGN Cross-sectional study. SETTING Rehabilitation center. PARTICIPANTS People with unilateral(More)
This study characterized measures of community activity and participation of transtibial amputees based on combined data from separate accelerometer and GPS devices. The relationship between community activity and participation and standard clinical measures was assessed. Forty-seven participants were recruited (78% male, mean age 60.5 years). Participants(More)
Ipsilateral primary motor cortex (M1) reorganisation after unilateral lower-limb amputation may degrade function of the amputated limb. We hypothesised unilateral lower-limb amputees would have a bilateral increase in corticomotor excitability, and increased excitability of ipsilateral M1 would be associated with increased step-time variability during gait.(More)
BACKGROUND Impaired balance is common in neurological disorders. Cervical dystonia is a neurological movement disorder affecting the neck. The effect of this aberrant head posture on physical function is unknown. OBJECTIVES To compare balance, mobility, gait and stepping reactions between ten people with cervical dystonia and ten control adults. METHODS(More)
Spatial neglect is modeled on an imbalance of interhemispheric inhibition (IHI); however evidence is emerging that it may not explain neglect in all cases. The aim of this study was to investigate the IHI imbalance model of visual neglect in healthy adults, using paired pulse transcranial magnetic stimulation to probe excitability of projections from(More)
Chronic pain is prevalent in the western world; however fear of pain often has a greater impact than the degree of initial injury. The aim of this study was to explore the relationship between knowledge of the neurophysiology of pain and fear avoidance in individuals diagnosed with chronic pain. Twenty-nine people with chronic musculoskeletal pain were(More)
PURPOSE The aim of this study was to examine the effect of 6 min of walking on fatigue, exertion and spatiotemporal, kinematic and kinetic gait parameters in people with multiple sclerosis (MS). METHODS Thirty-four people with MS with moderate levels of disability completed measures of fatigue, exertion and instrumented gait analysis before and after(More)
Moving visual fields can have strong destabilising effects on balance, particularly when visually perceived motion does not correspond to postural movements. This study investigated relationships between visual field dependence (VFD), as assessed using the roll vection test, and reported dizziness, falls and sway under eyes open, eyes closed and optokinetic(More)