VARIABILITY OF STRIDE FREQUENCY AND PRONATION VELOCITY DURING A 16 DAY RELAY-RUN AROUND GERMANY – A CASE STUDY

Abstract

This case study analyzed stride frequency, represented by time of gait cycle (TGC), and maximum pronation velocity (MPV) for one subject running 350 km over 16 consecutive days. Data collection took place during a day-and-night team relay-race around Germany in 2008. TGC and MPV measurements were performed by a gyrometer incorporated in the subject’s running shoe and recorded by a portable data logger. For data analysis TGC and MPV velocity were determined in 25 runs for altogether 112,532 steps of the right foot. Means and standard deviations of both parameters for complete runs and for all consecutive five-minute segments within each run were calculated. Results showed an increase of TGC and a decrease of MPV within single runs. Between run comparisons across all 25 runs showed no systematic change in TGC and MPV during the relay-race. Interestingly, during the unfamiliar night-runs TGC and MPV were increased compared to day-runs, potentially caused by altered biorhythm or limited vision at night.