The purpose of this study was to examine the effects of interpersonal synchronization of stepping on stride interval dynamics during over-ground walking. Twenty-seven footswitch instrumented subjects walked under three conditions: independent (SOLO), alongside a partner (PAIRED), and side by side with intentional synchronization (FORCED). A subset of subjects also synchronized stepping to a metronome (MET). Stride time power spectral density and detrended fluctuation analysis revealed that the rate of autocorrelation decay in stride time was similar for both the SOLO and PAIRED conditions, but was significantly reduced during the FORCED and MET conditions (p=0.03 & 0.002). Stride time variability was also significantly increased for the FORCED and MET conditions (p<0.001). These data suggest that forced synchronization of stepping results in altered stride interval dynamics, likely through increased active control by the CNS. Passive side by side stepping, where synchronization is subconscious, does not appreciably alter stepping in this manner.
Nessler is with the Dept. of Kinesiology, California State University, San Marcos, CA, De Leone is with the Dept. of Physics, California State University, San Marcos, CA. Gonzales, Rhoden, and Steinbrick are currently undergraduate students in the Dept. of Kinesiology at California State University, San Marcos.