Strength asymmetry between front and rear leg in elite snowboard athletes

Objective:To examine possible bilateral strength asymmetries between the front (FL) and the rear leg (RL) in elite snowboard athletes due to the imposed asymmetrical position on the board.Design:Observational study.Setting:Department of Biomedical Sciences for Health, University of Milan.Participants:Thirty-three elite male snowboarders: 12 alpine athletes (SBalp), 11 snowboardcross athletes (SBx), and 10 freestyle athletes (SBfs).Intervention:Open and closed kinetic chain exercises.Main Outcome Measures:Maximal isometric voluntary contraction (MVC) and vertical jump force (VJFT).Results:Only SBalp athletes presented MVC and VJFT values in RL 9.9% and 11.3% greater than the corresponding value in FL (P < 0.001), respectively. No significant differences were observed in SBx and SBfs.Conclusions:A muscle strength asymmetry between FL and RL was detected only in elite SBalp. This asymmetry is lower than the +/- 15% cutoff interval used to define clinically relevant bilateral strength asymmetry and is likely to be explained by technical aspects. Indeed, only SBalp athletes naturally distributed the center of mass, and thus, the weight toward RL to have a good board control. This feature likely reflects a greater adaptation of the muscle characteristics.