Gait Variability while walking with three different speeds

Gait variability is defined as changes in gait parameters from one stride to the next. Gait variability increases in individuals affected by neurodegenerative conditions such as Parkinson's disease and Huntington disease, and also with falls in the elderly and incident mobility disability. In this work, we study speed-related and age-related gait variabilities in healthy adults. Ten participants, five females (three young and two middle-aged) and five males (three young and two middle-aged) were recruited to walk on an instrumented treadmill for three minutes in this study. The gait variables (stride length, stride width, stride time and stride velocity) were extracted and processed from camera motion system. Slow speed walking increased gait variability with all gait variables; only stride width variability was increased significantly in middle aged subjects compared with the young subjects (p<0.05), there were no changes in other variables. Based on gait variability differences in age, height and body mass, we propose to design a knowledge-base membership function of gait variability for all the related gait variables with different heights and weights (BMI) as cofactors in each age group. An automatic diagnostic tool, Fuzzy Inferential Reasoning system, will help the clinician to identify pathological impairment from normal.