Meeting Abstract

P3.168  Sunday, Jan. 6  Manipulation of the Structure of Gait Variability with Rhythmic Auditory Stimulus HUNT, N/H*; STERGIOU, N; University of California, Berkely; University of Nebraska, Omaha nathaniel.hunt@berkeley.edu

Gait is a rhythmic behavior that may be analyzed via discrete measures taken once per cycle, such as inter-stride time interval. Nonlinear analyses of the dynamics of a series of discrete measures identifying power law scaling or entropy are complements to more traditional linear analyses. These nonlinear measures quantify a specific temporal structure of gait variability in young healthy walkers that deviates systematically with the onset of aging or gait pathology. While gait therapies often focus on restoration of linear measures such as mean step length or the standard deviation of toe clearance, no studies investigate the effects of restoration of nonlinear measures of gait. We approach the restoration of nonlinear measures by driving gait rhythms with individualized rhythmic auditory stimulus. A strong, natural auditory motor coupling in humans promotes walking in synchrony with an external auditory stimulus. Taking advantage of this synchronizing phenomenon we designed individualized rhythmic auditory stimulus with a target temporal structure that was prescribed by one of three colored noise distributions (white, pink or brown noise). Ten subjects walked overground to each auditory stimulus for at least 612 strides. The monotonically increasing entropy and power law scaling patterns in the rhythmic auditory stimulus conditions were mirrored in the inter-stride time interval variability patterns of the subjects. This result opens the opportunity for experimental manipulation of these nonlinear measures, thus an investigation of a possible causal relationship between these measures and beneficial characteristics of gait.