Differences in head accelerations and physiological demand between live and simulated professional horse racing

The purpose of this study was to determine if there are differences in mechanical and physiological demand between live and simulated racing. Fifteen male professional jockeys (31.8±9.5 years, 160.78±7.62 cm, 51.2±1.5 kg) were instrumented with inertial measurement units (IMUs) placed on their helmets to measure mechanical stress and a heart rate (HR) monitor. Head accelerations and HR were measured during a live race (between 5.5 and 6.5 furlongs) and a simulated race (equivalent of 6.5 furlongs or 1.5 min) on a race horse simulator. Paired t-tests were used to determine if there were differences between the two racing conditions for each dependent variable. Alpha level was set at P < 0.05. Average HR and peak HR were significantly higher during live than simulated racing. The peak resultant linear acceleration, the average resultant linear acceleration, and the peak resultant rotational velocity were significantly higher in live racing than simulated racing. There were no significant differences in average resultant rotational velocity. Simulated racing trials had consistently lower values of head accelerations compared to live racing trials. These results may provide justification for the use of a race horse simulator as a tool capable of use in rehabilitating and returning jockeys to ride following injury as the accelerations and velocities measured on simulated racing trials were lower, suggesting a safer sports-specific exercise, while still approaching the physiological demands of live racing.