The activity of four muscles on each leg was simultaneously measured using electromyography. Similar to previous findings of elite junior race walkers in competition, half of the athletes had stride length differences, but imbalances in other variables were less common. In particular, vertical ground reaction force peaks were very similar between legs. However, the electromyography findings showed that some of the athletes had substantial differences between leg muscles with regard to activation levels, and that compensation occurred between synergist muscles (gluteus maximus and biceps femoris) within the same leg.
Coaches are advised to closely monitor the technical and strength development of their young athletes to ensure that both sides of the body are balanced. This is especially important with regard to preventing injury, maximising efficiency, and reducing the risk of disqualification.