Quantifying the Gait Pattern Adaptation to Auditory Feedback in Healthy Elder Adults

Several approaches using auditory feedback have been proposed to improve gait rehabilitation in Parkinson Disease. Despite auditory cues have shown to be useful, there are still unanswered questions about their optimal usage regarding parameters like frequency, number of beats and their integration with rehabilitation protocols, among others. Most approaches have attempted to resolve these questions by measuring their direct effect on spatiotemporal gait variables. However, few studies have assessed how synchronized the auditory feedback and the gait pattern are.The main goal was to quantify synchronization between the gait temporal patterns and the auditory stimuli. The group of participants consisted of seven (7) healthy subjects, aged between 50-70 years (average 57.28, +/- 5.87 years), with average height of 1.64 +/- 0.09 m and independent community ambulation. Each candidate was asked to sign an informed consent, given their good cognitive conditions for understanding the nature and purpose of the study. Participants were instructed to follow the sounds provided by a metronome. Feet tracking yielded the temporal gait pattern. The temporal coherence metric was developed to evaluate synchronization between audio signal and subject motion, in terms of phase shift (pi radian). Results show a good fit to auditory stimulus in metronome rates between 140-150 and 60-80 beats I min (bpm) for the selected participants. A lower temporal coherence was observed at the beginning and the end of the test. The proposed metric allows quantification of the temporal coherence between gait and auditory cues in healthy elder subjects. Other exploratory trials should be directed to evaluate the temporal coherence between auditory stimuli and generated movements in population with Parkinson Disease.