BIOMECHANICAL FEATURES OF PERFORMANCE DOMINANCE IN THE LOWER LIMBS

Abstract

INTRODUCTION: The kinematic, dynamic and myoelectrical characteristics of the one-foot vertical jump were examined for the dominant and the non-dominant foot, in order to determine the biomechanical features of performance dominance in the lower limbs. METHODS: Seventy-nine volunteers performed five vertical jumps with either foot on a piezoelectric force platform (Kistler). The sampling frequency was set at 1000 Hz. Three-dimensional analysis was employed for the determination of the kinematic characteristics of the movement, at a sampling rate of 60 Hz. The APAS system was used to record surface electromyograms of four muscles in the lower limb (sampling frequency 1000 Hz). The foot that achieved the highest performance was defined as the dominant foot. Correspondence analysis was employed for the evaluation of the data. RESULTS: The analysis of the data revealed that high performance scores were the output of a common movement pattern for both the dominant and the nondominant foot. Small values of the maximum angular velocity of the foot, leg and thigh were found during the supporting phase of the jump with either limb. The biceps femoris was highly activated before the contact of the foot, but presented less activity during the supporting phase of the jump. The activity of the biceps femoris before the supporting phase of the jump was greater when the jump was performed with the dominant foot. The vastus medialis of the dominant limb presented greater activity during the negative phase of the jump. Finally, the rectus femoris presented greater activity during the positive phase of the jump when the jump was executed with the dominant foot, while the activity of the gastrocnemius was less. CONCLUSION: The differences of the myoelectrical activity of the biceps femoris between the dominant and the non-dominant foot werprimarily responsible for the differences between the two feet in the height of the jump.