Date of Award

2014-01-01

Degree Name

Doctor of Philosophy

Department

Interdisciplinary Health Sciences

Advisor(s)

Anthony Salvatore

Second Advisor

Rebecca Reed-Jones

Abstract

Changing the direction of locomotion, often referred to as "steering", is an integral component of human locomotion. Steering requires maintaining dynamic balance while translating and rotating the body in the new travel direction. Given the level of sensation thought to be involved in sub serving goal directed modifications in steering, it is highly likely that steering control may require attention. Since attention resources decline with increasing age, we may see the influence of age on steering performance when attention resources are limited. Therefore, this study sought to investigate the role of attention in steering using a dual task paradigm in healthy young and healthy older adults. Twenty-five healthy young adults and nineteen healthy older adults completed the experimental protocol that involved baseline and dual task conditions. In the baseline condition, the participants walked and turned 900 at a comfortable pace. In the dual task condition, the participants walked and turned 900 while reciting serial 7 subtractions. We measured the time taken to turn, and the turn onsets of the eyes, head, trunk and pelvis in the baseline and dual task conditions. One-way ANOVA and Multivariate analyses ascertained the effects of age on the time taken to turn, and the turn onsets of the eyes, head, trunk and pelvis in the baseline and dual task conditions. The results of the study indicated a significant impact of age on steering performance under dual task conditions. In healthy young adults, the dual task condition increased the time taken to turn, but it did not affect the turn onsets of the eyes, head, trunk and pelvis. In older adults however, the dual task condition not only increased the time taken to turn, but it also altered the turn onsets of various body segments. These results provided evidence that steering performance varied with age, under dual task conditions. This is an important finding as turning in activities of daily living are rarely done in isolation of a secondary motor or cognitive task. Disruption of steering performance could place older adults at risk of disruptions to turning movements, resulting in a loss of balance and/or falling. Future research should focus on studying the level of variance in steering due to dual tasking that might infer details about the nature of motor control during turning in older adults.

Language

en

Provenance

Received from ProQuest

File Size

129 pages

File Format

application/pdf

Rights Holder

Venkata Naga Pradeep Ambati

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