Thesis (M.S.)--Oregon State University, 2007. / Printout. Includes bibliographical references (leaves 77-81). Also available on the World Wide Web.

Thesis (Ph. D.)--University of Oregon, 2006. / Includes vita and abstract. Includes bibliographical references (leaves 127-135).

Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 127-135). Also available for download via the World Wide Web; free to University of Oregon users.

Thesis (Ph. D.)--University of Oregon, 2006. / Includes bibliographical references (leaves 127-135). Also available online (PDF file) by a subscription to the set or by purchasing the individual file.

M.Tech. (Chiropractic) / During gait the force transferred through the body is dived between the two lower limbs, according to Kaplan, Barak & Spiel (2012) this force should to be constant and equal with each gait cycle in an asymptomatic individual. In the presence of spinal dysfunction there is an alteration of sensory motor integration as a result of impaired proprioception (Taylor & Murphy, 2007), this altered proprioception may then produce a negative effect on the fore distribution during gait, resulting in abnormal biomechanics and an altered gait pattern. Chiropractic adjustments have been shown to restore normal biomechanics to the spine and in so doing improve proprioception. The purpose of this study was to determine the effects of cervical and lumbar chiropractic adjustments on the force distribution through the lower limbs during gait. Method: Thirty participants between the ages of 18 and 45 were invited to participate in the study. The details of the study were fully explained to each participant, after which an informed consent form was signed, followed by a full physical examination to determine if the potential participant was eligible for inclusion in the study, and did not have any of the following exclusion criteria. Individuals suffering from any form of mechanical back pain, hip, knee and ankle pathologies, females, and individuals were manipulation was contra-indicated were excluded from the study. A full lumbar or cervical spine examination was then performed in order to test for joint dysfunction. The participants then underwent gait testing after which they then received either a cervical or lumbar spine adjustment to the dysfunctioning joint. Procedure: The participants received a total of seven chiropractic adjustments with the objective data being recorded on the first, fourth and seventh consultations. The objective data was captured with the Zebris FDM gait analysis system. The system consisted of a 3 meter long sensory platform that is built into the floor, the pressure platform was made up of multiple force sensors arranged in a matrix of columns and rows and was capable of measuring the exact force through each lower limb during gait. The recorded sensory information was transferred to the WinFDM program which then interpreted all the data.

Background. Accidental falls comprise a serious health concern in older adults. Partially accounting for the high incidence rates is postural instability. While customized foot orthotics can improve certain measures of functional stability, the purpose of this study was to explore the degree to which prefabricated orthotics benefit this population and to expand the evidence base to postural stability. Methods. Eighteen healthy older adults (72.7 ± 4.8 years) were evaluated with and without foot orthotics, and again following 2-3 weeks of use. Functional stability was evaluated via the Timed-Up-and-Go test and the Fullerton Advanced Balance scale. Computerized posturography was used to assess stability in altered sensory environments (Sensory Organization Test) and to assess overall stability limits (Limits of Stability test). A pressure analysis system assessed gait parameters and pressure distribution patterns. Results. Foot orthotics improved stability on the Timed-Up-and-Go (p=0.003) and the Fullerton Advanced Balance Scale (p<0.001) and decreased fall occurrence on the Sensory Organization Test. Times based changes of postural stability occurred for medio-lateral sway velocity and area when only the vestibular system providing accurate information (condition 5) (p=0.001, 0.05, respectively), and under sensory conflict (condition 6) for sway velocity (medio-lateral and antero-posterior), sway path length and sway area (p=0.015, 0.021, 0.015, 0.015, respectively). An interaction effect was found for maximum excursion composite score (p=0.001) on the Limits of Stability test, as well as a main effect of time for directional control in the ML direction and composite score (p=0.024.0.043). Contact area increase in the midfoot and rearfoot and peak force decreased in the rearfoot (p=0.001, 0.03, 0.027, respectively). Conclusions. Results indicate that foot orthotic use can improve functional measures of stability in older adults. It is unclear whether the time-based changes in postural stability are attributable to the orthotics or are a result of learning effects. Regardless, improvements in stability with prefabricated foot orthotics may help decrease the risk of falls in this population. / School of Physical Education, Sport, and Exercise Science

Human balance control is a complex feedback system that must be adaptable and robust in an infinitely varying external environment. It is probable that there are many concurrent control loops occurring in the central nervous system that achieve stability for a variety of postural perturbations. Though many engineering models of human balance control have been tested, no models of how these controllers might operate within the nervous system have yet been developed. We have focused on building a model of a proprioceptive feedback loop with simulated neurons. The proprioceptive referenced portion of human balance control has been successfully modeled by a PD controller with a time delay and output torque positive feedback. For this model, angular position is measured at the ankle and corrective torque is applied about the joint to maintain a vertical orientation. In this paper, we construct a neural network that performs addition, subtraction, multiplication, differentiation and signal filtering to demonstrate that a simulated biological neural system based off of the engineering control model is capable of matching human test subject dynamics.

Thesis (Ph. D.)--University of Oregon, 2006. / Typescript. Includes vita and abstract. Includes bibliographical references (leaves 96-104). Also available for download via the World Wide Web; free to University of Oregon users.

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 (Ph. D.)--University of Oregon, 2002. / Includes bibliographical references (leaves 178-188). Also available online.