The development of movement effectiveness in children : a qualitative analysis
Qualitative biomechanical analysis of movement effectiveness can be proposed as an innovative approach to oversee motor skill development in boys and girls of school age, since it permits an appreciation of how effective the movement is in attaining the performance criterion. Analysis of movement effectiveness involves establishing, first, the technical level of the child and, second, the mechanical effectiveness of the movement performed by the child. The assessment of technical level involves basic analysis of the main form of the movement and provides an initiation to biomechanical analysis; whereas, analysis of mechanical effectiveness consists of a follow-up comprehensive analysis. The present research aimed to qualitatively determine, and study gender differences in the development of, movement effectiveness in children. The research included both cross-sectional (N = 187 children) and longitudinal (N = 55 children) studies. A group of adults (N = 31) were used as controls. The subjects were asked to perform two consecutive trials of the soccer kick, the overarm throw and the standing broad jump, all for maximum distance, which were recorded on videotape. In Study 1, hierarchical models were developed to qualitatively establish the technical level of the subjects and to study the development of technical level in children. In Study 2, a model for the qualitative analysis of mechanical effectiveness was constructed. The model allows the integration of phase analysis and mechanical analysis using movement principles in order to select important variables for the analysis. Rating scales for each variable of the three motor skills were outlined and, then, fine-tuned using tests of rater accuracy and intra-rater reliability, in order to create scoring references. Inter-rater reliability in the use of the scoring references was acceptable. In Study 3, the development of mechanical effectiveness in children was examined, and the relative contribution of specific variables to performance was assessed. Generally, in the cross-sectional studies male children showed a higher technical level and higher mechanical effectiveness, and also a faster rate of development, in the soccer kick and the overarm throw. However, male and female children were better matched in the standing broad jump. The longitudinal studies were inconclusive. Not all adult subjects, particularly females, had reached maturity of movement patterns. The knowledge gained in the research may be used to guide effective progression in coaching and curriculum development in education.