EMG structure, ground reaction forces as anticipatory indicators of the fencing lunge effectiveness

Background and Study Aim: The efficiency of influence of the phenomenon of anticipation on the effectiveness of the most classic technical attack in fencing, which is a straight lunge in epee on the opponent's trunk, is expressed in terms of acti- vating the muscles of the legs and postural indicators recorded as vertical ground reaction forces (GRF) characterized by a delay in relation to EMG signal. The main objective of the research reported in this paper is knowledge about the influence of the phenomenon of anticipation on the effectiveness of a straight lunge in epee on the opponent's trunk. Material and Methods: Seven of the world's leading athletes, medal-winners of the World Championships and Europe, both in individual and team tournaments, took part in the research. Three research tools applied EMG, ground force re-action platform and the motion capture system (OPTI TRACK). Results: The research demonstrated a high level of correlation coefficients between the force exerted in the rear leg and EMG of the LAT GAS (caput laterale) muscles (r = 0.861) and MED GAS (caput mediale) r = 0.874, for the statistical significance level of p < 0.05. These values indicate a delay of the vertical force to the EMG of about 15 ms. The values of temporal indicators: reaction time (RT) and movement time (MT) indicate the greatest level of correlation with the activation times of the following muscles: PRT TB (premotor reaction time tri- ceps brachii) r = 0.893; PRT ECR (-extensor carpi radialis) r = 0.863) as well as MRT FZ (movement time Fz) rear (r = 0.824) as an indicator of strength. Both phases (premotor RT and motor RT) determine the effectiveness of the fencing lunge, i.e. decrease of the duration of complex response time RT Conclusions: The phenomenon of anticipation applies to both the premotor time and motor RT intervals. The results of the research also confirmed that the effectiveness of the lunge depends on the speed of activation of the triceps brachii and the volume of EMG generated by the gastrocnemius muscles of the rear leg.