Choice neuro-motor reaction time (CNMRT) and relevant speed of movement (CVM) in children aged 6 to 11

Introduction One of the most important neuro-motor characteristics that athletes devoted to " Open-Skill " sports need is a suitable "time of neuro-motor reaction", skill they show in the playground to face a fast game action , anticipated or unpredictable, in the briefest time and in the most effective way for oneself, in the individual sports, for oneself and for the companions in the team sports. The total time of neuromotor reaction (NMRTT) is what exists between appearance of the stimulus, and the beginning of the muscular response. In this study NMRTT has been evaluated throught the choice neuromotor reaction to a visual stimulus. According to the most recent studies, the NMRTT = reaction time (RT) + time of movement (TM) and RT = pre motor time that exists between the application of the stimulus to the action and the modifying electromyography (EMG) of the muscles that will then be recruited, + elettro-mechanical delay, represented by the temporal interval that exists between the arrival of the EMG signal and the beginning of the movement. Methods In this study we wanted to examine the choice neuromotor response and the initial speed of release in 102 children, aged 6-11, attending an Italian elementary school such to observe the eventual variations according to the age (Tab.1). The instrumentation used for such evaluation has already been published1 and is constituted by 6 elements: - a springboard of departure;- a double series of photocells (the first couple placed in line at 3.5cm distance to the tibial crest of the child legs and the second couple placed in a more advanced position, 10cm far from the previous couple); - a series of six pillars ( 3 on the left and three on the right) with a bright led to order;- a switchboard, joined output-input to the instrumentation arranged on the field, in a position to manage the starting of the led, to determine the latency between the arrival of the stimulus and neuromotor response of the children and to calculate the speed of the limb passage across the photocells system; - an equipped computer with an appropriate software to distribute the visual stimulus in the moment it is wanted by the tester and to receive the returning signals from the equipment, working them out in real time; -a printer. Results Through this study we have been able to verify a quantitatively noteworthy difference in the choice neuromotor response and in the initial movement speed among the group A (children aged 6 to 7) and the groups B and C (children aged 8 to 11); in the three groups a correlation exists among personal age and speed of movement . Discussion/Conclusion According with a recent study about SNMRT2 ( simple neuro-motor reaction) results about CNMRT allows us to state that between the ages 6-7 and 8-9 the nervous maturation is more marked than in two following periods. The reduction of CNMRT and the relevant speed of movement (CMV) in correspondence with the progress of the age, represent positive indicators of development and maturation of the nervous system in the child. What remains to be difined is if such correlation will be confirmed in the successive age, with gender differences, and if it also exists in referring to a more elevated number of choices ( more than 6) . References 1 Minelli R.,D’Introno L., et al (1995) Medicina dello sport , vol 48, n.3. 2 F.Casolo et al. (2004) , ECSS Clermont Ferrand Welford A.T. (1908) , Reaction time Schmidt R.A.,Wrisberg C.A. (2000) Motor learning and performance