The effects of speed and performance level on race walking kinematics

Purpose Race walking is a very technical discipline of athletics, which is regulated by two peculiar constraints: straighten knee from heel strike to midstance and flight phase absence while race-walking. For this reason, several studies addressed technical factors as determinant of ath- letes’ performance. The aim of this study was to analyse differences in technique across athletes’ levels (regional— national—international), and describe race walking kine- matics at increasing speeds. Methods Fifteen athletes race-walked for 1 min on a treadmill at increasing speeds (from 2.78 m s-1 to exhaustion). Three-dimensional kinematics data were recorded through a motion capture system sampling at 300 Hz. Results Step length, step frequency and flight time increased linearly with speed, but step length was the major determinant to raise speed. At increasing speeds, joints angles curves reported a backward time shift (e.g., antici- pation of the movement), without altering joints range of motion, a further evidence of the rules influence on ath- letes’ technique. Among athletes’ levels the only difference found regarded the maximal race walking speed: interna- tional 4.97 ± 0.25 m s-1, national 4.61 ± 0.14 m s-1 and regional 4.22 ± 0.14 m s-1. Conclusion Athletes’ angular kinematics did not change increasing race-walking speed and did not show differences among athletes’ performance level. Further studies with combined metabolic and electromyography analyses are needed to better elucidate performance determinants and discriminate athletes’ level.