Gait alterations during constant pace treadmill racewalking

Racewalking is an Olympic event requiring great endurance, and racewalkers often use treadmills in training because of the benefits of having a flat, unchanging surface where pace judgment can be learned, and because inclement weather can be avoided. The effects of fatigue associated with racewalking on a treadmill have not been studied, and could be informative with regard to the maintenance of legal technique. The aim of this study was to measure key gait variables during a physically demanding treadmill racewalk. Fourteen international racewalkers completed 10 km on an instrumented treadmill at a pace equivalent to 103% of their recent best time. Spatiotemporal and ground reaction force data were recorded at four distances. High-speed videography data were simultaneously recorded to analyze changes in knee angle between the early and late stages. Increases in step length and corresponding decreases in cadence were found, although the small changes were not considered meaningful. There was also a small increase in flight time and a small decrease in push-off force. There were no other significant changes for any other variables (including knee angles). The increase in flight time might be important given that racewalkers are not permitted a visible loss of contact and suggests that fatiguing sessions on a treadmill can lead to the adoption of non-legal technique. However, this disadvantage of treadmill training can be negated if the coach scrutinizes the athlete throughout the session, and overall the consistent technique used is of benefit with regard to learning correct form and pacing ability.