KNEE FLEXOR IMBALANCES IN ELITE SNOWBOARD RACERS

Abstract

341 Snowboard racing requires that the snowboard rider position themselves with either their right or left leg forward on the snowboard. We hypothesized that this asymmetric position on the snowboard may place differing demands on the skeletal musculature during snowboarding resulting in muscle strength imbalances. Three women and six men from the U.S. Snowboard National Team, all racers, were tested for knee extension and knee flexion torque strength. All althletes were tested in concentric extension and concentric flexion at 60 degrees per second on a Cybex (6000) isokinetic dynamometer. Knee extension musculature was equally balanced between legs with an average torque of 212.42 ± 30.96 Newton*meters for the front leg knee extensors and 213.35 ± 32.62 Newton*meters for the rear leg knee extensors (p=0.44). Torque of the front leg knee flexors averaged 118.94 ± 20.78 Newton*meters, while torque of the rear leg knee flexors averaged 131.43 ± 35.39 Newton*meters (p=0.03). It is concluded that snowboard racing due to its asymmetric stance facilitates skeletal movements which lead to stronger rear leg knee flexors when compared to the front leg knee flexors, while front and back knee extensors are equal in strength. The rear leg knee flexors may be exercised to a greater degree due to the muscular actions involved in snowboarding, specifically steering, tip pressure, and/or ambulating on flat terrain. These muscular imbalances between front leg and rear leg knee flexors, if uncorrected, may lead to orthopaedic problems in the athlete's future.