The goal of this thesis was to explore the usability of on-foot sensors for ambulatory gait analysis. Using a human factors engineering approach, two different ambulatory gait analysis prototypes were assessed in two separate studies. The first study was conducted with student participants in a university setting and the second study was conducted in-situ with neurorehabilitation patients at Bridgepoint Hospital. The usability and patient experience of the prototypes were assessed, and based on these findings a set of recommendations was developed. These issues and recommendations are detailed in this thesis and are expected to inform the design of future iterations of the prototypes.

The strength of time-dependent correlations known as stride interval (SI) dynamics have been proposed as an indicator of neurologically healthy gait. Most recently, it has been hypothesized that these dynamics may be necessary for gait efficiency although the supporting evidence to date is limited. To gain a better understanding of this relationship, this study investigated stride interval dynamics, the energy cost of walking, and physical activity in a pediatric population. The findings indicate that differences in energy cost are not reflected in the stride interval dynamics of able-bodied children. Interestingly, increasing physical activity levels were associated with decreasing variance in stride interval dynamics between subjects, though this finding only approached significance (p=0.054). Lastly, this study found that stride interval dynamics in children as young as nine years were comparable to stride interval dynamics found in healthy young adults.

Stair-climbing is an important skill for promoting independence and activities of daily life and is a key component of rehabilitation therapies for physically disabled children. This thesis describes the design and evaluation of an interactive musical stairs system for children engaged in stair-climbing physical therapies. The achievement of a targeted therapeutic goal, namely, use of reciprocal steps, was significantly increased by 6% [SD=7%] (p=0.007) with the presence of audio feedback. Levels of participant enjoyment and motivation increased as well. This led to the development of an automated system, using inertial sensors to detect initial contact (IC) events each time a child makes a step, to trigger audio feedback. A semi-generic algorithm was designed that was able to detect 96% [SD=3%] of IC events during stair-climbing therapy sessions. This thesis lays the groundwork for future longitudinal research investigating the efficacy of audio feedback in stair-climbing and other rehabilitation therapies as well.

The goal of this thesis was to explore the usability of on-foot sensors for ambulatory gait analysis. Using a human factors engineering approach, two different ambulatory gait analysis prototypes were assessed in two separate studies. The first study was conducted with student participants in a university setting and the second study was conducted in-situ with neurorehabilitation patients at Bridgepoint Hospital. The usability and patient experience of the prototypes were assessed, and based on these findings a set of recommendations was developed. These issues and recommendations are detailed in this thesis and are expected to inform the design of future iterations of the prototypes.

Objectives: To describe the relationship between sensorimotor function and walking in incomplete SCI. Methods: 25 subjects were assessed using Lower Extremity Motor (LEMS) and Pinprick (LEPS) scores, and 7 walking measures: FIM-Locomotor Score, Assistive Device Score, Walking Index for SCI, 10-metre Walk Test (10mWT), Timed Up and Go (TUG), Six-Minute Walk Test (6MWT) and Walking Mobility Scale. Results: Walking and sensorimotor function varied between subjects. Walking measures significantly correlated with LEMS and individual leg muscles but not LEPS. 21/22 ambulatory subjects had LEMS threshold>20. Non-ambulatory subjects didn’t achieve threshold. Not all subjects completed all walking measures: 10mWT: n=19; TUG: n=14, 6MWT: n=13. Most walking measures were significantly related. 10mWT and 6MWT were highly correlated. Subjects walking0.95 m/s didn’t reach predicted 6MWT. Conclusion: Lower extremity strength is important for walking and should be further examined with other factors in a range of subjects across different measures to fully understand these relationships.

The purpose of this thesis is to investigate the reaction to a purely unexpected slip during gait termination and subsequent experiences stopping on the slippery surface in participants who are young and healthy, older and healthy and who have Parkinson’s disease while on traditional dopamine-replacement medication. Gait termination requires control of the forward momentum of the body’s centre of mass (COM). This forward momentum must be dissipated and the COM held within a newly formed base of support. The challenge of stopping on a slippery surface involves maintaining stability while transitioning from steady-state locomotion to steady-state stance. Experience with a slippery surface changes postural and gait characteristics to diminish the perturbing effect of the slip. The magnitude of the slip response diminishes quickly as the movement becomes more efficient. Our investigations revealed a typical slip response to a purely unexpected slip during gait termination including a lowering of the COM, an increased muscular response to support the body, a shortened step and an arm raise. Knowledge of and experience with the slippery surface quickly changed the slip response to reduce the perturbing effect of the slip and also to increase the efficiency of the response while smoothly transitioning from steady-state locomotion to gait termination. Parkinson’s disease impairs balance control, the ability to switch between motor tasks and also to stop within two steps. The need for a voluntary change in motor programs along with difficulty stopping and increased instability makes gait termination a potentially difficult task for someone with Parkinson’s disease (PD). The participants with PD used a slower, safer strategy to stop on non-slippery surfaces to compensate for their instability compared to age-matched controls. When a slip was first introduced during gait termination, the participants with PD continued to be less stable in the plane of progression than the control group. Despite the instability, the PD group was still able to integrate a balance-correcting response into a voluntary gait termination program. The ability to generate adaptive strategies to integrate the balance-correcting response into a voluntary gait termination program over multiple trials does not appear to be affected by PD; both the control group and PD group showed behavioural modifications according to repeated exposures to the slippery surface. Although participants with PD seemed slightly less stable and walked slower, their behavioural adaptations were similar to the control group.

The purpose of this thesis is to investigate the reaction to a purely unexpected slip during gait termination and subsequent experiences stopping on the slippery surface in participants who are young and healthy, older and healthy and who have Parkinson’s disease while on traditional dopamine-replacement medication. Gait termination requires control of the forward momentum of the body’s centre of mass (COM). This forward momentum must be dissipated and the COM held within a newly formed base of support. The challenge of stopping on a slippery surface involves maintaining stability while transitioning from steady-state locomotion to steady-state stance. Experience with a slippery surface changes postural and gait characteristics to diminish the perturbing effect of the slip. The magnitude of the slip response diminishes quickly as the movement becomes more efficient. Our investigations revealed a typical slip response to a purely unexpected slip during gait termination including a lowering of the COM, an increased muscular response to support the body, a shortened step and an arm raise. Knowledge of and experience with the slippery surface quickly changed the slip response to reduce the perturbing effect of the slip and also to increase the efficiency of the response while smoothly transitioning from steady-state locomotion to gait termination. Parkinson’s disease impairs balance control, the ability to switch between motor tasks and also to stop within two steps. The need for a voluntary change in motor programs along with difficulty stopping and increased instability makes gait termination a potentially difficult task for someone with Parkinson’s disease (PD). The participants with PD used a slower, safer strategy to stop on non-slippery surfaces to compensate for their instability compared to age-matched controls. When a slip was first introduced during gait termination, the participants with PD continued to be less stable in the plane of progression than the control group. Despite the instability, the PD group was still able to integrate a balance-correcting response into a voluntary gait termination program. The ability to generate adaptive strategies to integrate the balance-correcting response into a voluntary gait termination program over multiple trials does not appear to be affected by PD; both the control group and PD group showed behavioural modifications according to repeated exposures to the slippery surface. Although participants with PD seemed slightly less stable and walked slower, their behavioural adaptations were similar to the control group.

Thesis (M.S.)--Worcester Polytechnic Institute. / Keywords: DFA; fractal analysis; knee pads. Includes bibliographical references (p. 61-62).

Thesis (Ph. D.)--University of Oregon, 2003. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 157-170). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (M.S.)--East Carolina University, 2009. / Presented to the faculty of the Department of Exercise and Sport Science. Advisor: Paul DeVita. Title from PDF t.p. (viewed May 4, 2010). Includes bibliographical references.