Graham John Chapman

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There is increasing evidence that gaze stabilization with respect to footfall targets plays a crucial role in the control of visually guided stepping and that there are significant changes to gaze behaviour as we age. However, past research has not measured if age-related changes in gaze behaviour are associated with changes to stepping performance. This(More)
The aim of the present study was to investigate whether there are age-related changes in the ability of individuals to use vision to plan (feedforward control) and guide (on-line control) foot placement during locomotion. This aim was achieved by constraining the availability of vision and comparing the effects on the stepping performances of older and(More)
Previous research has highlighted differences between older adults determined to be at a low-risk of falling (low-risk) and older adults prone to falling (high-risk) in both where and when they look at stepping targets and the precision with which they subsequently step. On the basis of these findings, we proposed that high-risk older adults prioritise the(More)
Functional electrical stimulation (FES) of the triceps to restore control of elbow extension was integrated into a portable hand grasp neuroprosthesis for use by people with cervical level spinal cord injury. An accelerometer mounted on the upper arm activated triceps stimulation when the arm was raised above a predetermined threshold angle. Elbow posture(More)
PURPOSE A recent study suggested that updated spectacles could increase fall rate in frail older people. The authors hypothesized that the increased risk may be due to changes in spectacle magnification. The present study was conducted to assess the effects of spectacle magnification on step negotiation. METHODS Adaptive gait and visual function were(More)
This study investigates if there are age- and falls-risk related differences in the length of time individuals need following fixation of a stepping target in order to step accurately onto it. This aim was achieved by manipulating the timing and location of stepping target presentation and comparing the effects on stepping performance between young adults,(More)
When stimulating muscles, EMG signals recorded in neighboring muscles can be contaminated by stimulus artifacts, and artifact deletion is necessary. We have devised a digital technique for removing stimulus artifacts from rectified EMG recordings in muscles which lie close to a stimulated muscle. This artifact deletion method replaces the rectified EMG(More)
This randomised feasibility study aimed to examine the clinical and biomechanical effects of functional foot orthoses (FFOs) in the treatment of midfoot osteoarthritis (OA) and the feasibility of conducting a full randomised controlled trial. Participants with painful, radiographically confirmed midfoot OA were recruited and randomised to receive either(More)
This study investigated the importance of binocular vision to foot placement accuracy when stepping onto a floor-based target during gait initiation. Starting from stationary, participants placed alternate feet onto targets sequentially positioned along a straight travel path with the added constraint that the initial target (target 1) could move in the(More)
Studies of lateral wedge insoles (LWIs) in medial knee osteoarthritis (OA) have shown reductions in the average external knee adduction moment (EKAM) but no lessening of knee pain. Some treated patients actually experience increases in the EKAM which could explain the overall absence of pain response. We examined whether, in patients with painful medial OA,(More)