BIOMECHANICS OF SPORT PATTERNS AND MOTOR DEVELOPMENT

  • Anik'o Barab'as

Abstract

INTRODUCTION As the fundamental movement patterns are refined through practice and instruction, the quality and quantity of performance improve, and the patterns are integrated into more complex motor activities, such as those in games and sports. Developmental biomechanics is the study of movement patterns and how they change. due to interaction between human beings and their environment. The majority of research concerning motor development has been focused upon children . These studies have been descriptive in nature, with limited process-oriented experimentation. The stage theory is the primary analytical model for the study of developmental movement patterns (Stage theory models were advanced by Wild, 1938; Seefeld et al, 1982; Sybstages were introduced by Roberton et al., 1976; Adrian, Toole, Randall proposal is that movement patterns be considered as a continuum rather than aso discrete stages.) There are representative movement patterns of children and assessment of developmental stages. One of the Biomechanical approach is to identify the range'of motion, planes of motion and axis of motion. If the goal is maximum speed or distance, then the level of maturation of the movement pattern is evaluated by the amount and complexity of space , temporal aspects, sequencing of the body parts and the speed of these parts utilised, The maturation, the highest stage of development means the fastest and most effective timing of the body parts. Motor development is one part of the study of human development. The growth and development is manifested in both physical structure and motor performance These factors interact and are determined genetically as weil as soci,ally, culturally and economically. 58 The aim of this lecture was to discuss the biomechanical requirements during ,the motor pattern development pracess and to display the motor performance scores, referential values of motor development in different stage of different groups categorised by gender and age expressed in percentiles, based on crosssectional investigation of Hungarian youth (Eiben, Barabas,Pant6, 1991; Bretz Käske, 1994) The motor performance development appears in the most important factors such as strength (explosive strength or power), muscular endurance, running speed, balance, flexibility and connected with aerobic performance. METHODS A variety of motor tests can be used to document levels of motor development. Strength is included with motor performance because it is an essential component of motor performance and because motor performance tasks are often used as indicator of aspects of muscular strength. Tests of strength and motor performance obviously overlap. Performance tests incorporating fundamental motor skills require some combination of strength and motor control in jumping, throwing arid running task too. The motor performance tests used to assess motor development were: hand grip strength, standing broad jump, medicine ball push, 30 sec sit-ups, 60 m dash and 12 min. endurance run (Haag-Dassel, 1975; Mathews) Measurable neuromuscular modifications characterise the growing process of children and adolescents. Characteristics and performances of postural contral system are affected by the alterations of sensory and muscular subsystems. The stability of equilibrium in an upright posture, postural sway modifications accompany the normal ageing process. In the posturographic investigation the displacements of centre of pressure as weil as the vertical projection of centre of mass, the time functions on anteroposterior and mediolateral directions and Fourier spectra have been recorded in traditional and / or sharpened Romberg positions, with open and closed eyes Special track tasks with voluntary moving of centre of pressure have been solved by the subjects with audio-visual feedback. There are data of different agegroups to lay the foundation of mass Investigations in the schools as weil as special equilibrium measurements in sports requiring high accuracy equilibrium (Subjects of nursery school, primary school, secondary school and university student took part in the investigation.) The measuring equipment included "Adam type" force platform, Psycho 8 differential measurement device, ADDON microcomputer and personal computer. The measuring programs were (1) stabi,lometry in a traditional Romberg position, (2) movement co-ordination test in connection with the voluntary displacement of centre of mass contralIed by an audio-visual biofeedback system. (3) Dispersion display of sampled data describing the moving of the centre of mass, completed with displacement -time diagram and Fourier spectra RESULTS Strength and motor performance generally improve with age during childhood and adolescent, but the pattern of improvement is not uniform for all task. There are fundamental differences between performances of boys and those of girls in each age group and each test The boys performances are higher and better than those of girls The differences among the girls' age groups decreased as their age advanced and they finally stabilised at a relatively low value and a relatively early age, at the age of 12-13. This phenomenon appears in every performance test Changes in measured performance values of static strength (hand grip strength), muscular endurance (sit-ups), jumping performance (standing broad jump), throwing performance (medicine ball push), running performance (60 m dash and 12 min endurance run) are presented and discussed. The age -and sex-associated trends in strength and motor performance derived from cross-sectional (Hungarian Youth Study) and longitudinal studies (Beunen & Malina, 1988) are consistent Significant correlation has been found between the results of Romberg test (with closed eyes) and the co-ordination test described above as weil as between the co-ordination test performance and the reaction time. Real time visual feedback enhances motivation and helps the subject link perception to movement Fourier spectra ref/ect the nature of the sway and give objective information about amplitudes of harmonic components of body sway as weil as the dominant frequencies. CONCLUSIONS Gradual neuromuscular maturation and the development of a variety of fundamental movement patterns occur. during childhood The fundamental motor skills are reasonably developed in most children by age six or seven, although the mature patterns for same basic skills develop somewhat later. Strength and motor performance generally improve with age during chi/dhood and ado/escence, but the pattern of improvement is not uniform for all tasks Growth and development, changes of anthropometrical variables of the structure influence the functions as weil as the location of centre of gravity, mass of muscle, length of extremities As the main propelling force in the stepping-running-jumping pattern is derived from extension at the knee; to this is added the force of gravity, which rotates the entire body around the metatarsophalangeal joints and the extension at the ankle and hip keep the eentre of gravity in an advantageaus position to move it in the desired direclion we have to assume basic determination of motor pattern by growth and development .