The primary objective is to train the candidate to perform research as a productive, independent investigator in gait function of persons with age related diseases and disabilities. The candidate is pursuing backgrounds in biomechanics and motor control. She is a student at the dissertation research stage of her doctoral training who plans to apply her analytical background to biomedical research questions in clinical populations. The candidate will complete strategically selected coursework and receive intensive research training related with aging and pathological populations. She will enhance her research experience by completing lab rotations in four state-wide laboratories, where she will interact with other scientists. Dr. Nick Stergiou and Dr. Iraklis Pipinos will mentor the candidate's research development and guide her in rigorous research training for the study of gait function in persons with age related diseases and disabilities. The primary objective of this research is to determine the effect of age and restricted blood flow on gait parameters by examining gait variability during walking. The specific mechanisms that contribute to gait dysfunction in peripheral arterial disease (PAD) patients are unclear, despite considerable research efforts. Mobility problems in PAD patients are most commonly attributed to intermittent claudication, however, other manifestations of PAD could be contributing to the problem. Identifying the mechanisms leading to functional problems and determining how much disease is exaggerating the problem is vital to establishing proper screening and treatment protocols for PAD. Methods from nonlinear dynamics, which are being used progressively more in the study of biological phenomena, will be used to analyze and quantify gait variability from joint angle data during walking. Gait variability during normal walking will be compared to walking following induced ischemia in healthy young and older subjects. Data will be subsequently compared to gait variability in PAD patients, who experience ischemia as a result of the disease. We hypothesize that the induced ischemia conditions will lead to altered gait variability in both healthy young and older subjects, and that gait variability will be similar in the induced ischemia condition compared to the natural ischemia experienced by PAD. The proposed research will further our understanding of the effect of blood flow on functional impairments in PAD patients. This information will influence diagnosis procedures and may identify risk of falling in older persons who have PAD but may not experience symptoms. Results of this research will lay the groundwork for future studies evaluating treatment effectiveness and developing rehabilitation protocols to improve physical function and decrease injury risk in older patients.