Mechanical and Muscular Coordination Patterns during a High-Level Fencing Assault

Abstract

This study aimed to investigate the coordination of lower limb muscles during a specific fencing gesture in relation to its mechanical effectiveness. Maximal isokinetic concentric and isometric plantarflexor, dorsiflexor, knee and hip extensor and flexor torques of 10 female elite saber fencers were assessed and compared between both legs. Sabers completed three trials of a specific fencing gesture (i.e., marché-fente) on a 6.60-m-long force platform system. Surface EMG activities of 15 lower limb muscles were recorded in time with ground reaction forces and separated into four distinct assault phases. EMG signals were normalized to the muscle activity assessed during maximal isometric contraction. Mechanical and EMG data were compared between both legs over the entire assault and in each phase (ANOVA). Potential correlations between muscle strength and average EMG activities were tested (Bravais-Pearson coefficient). EMG activity patterns showed that rear hip and knee extensor and plantarflexor muscles were mainly activated during propulsive (concentric) phases, while front hip and knee extensor muscles were strongly solicited during the final braking (eccentric) phase to decelerate the body mass. Although fencers presented greater maximal hip (+10%) and knee (+26%) extensor strength in the front than in the rear leg (P < 0.05), rear hip and knee extensor strength was significantly correlated to the maximal anteroposterior velocity (r = 0.60-0.81). Moreover, muscle activity of the rear extensors was related to average velocity during the second propulsive phase (phase 3). This study gathers the first evidence of a crucial role of the rear extensor muscles in fencing speed performance. Such findings suggest interesting perspectives in the definition of specific training or rehabilitation programs for elite fencers.