• A. Ferreira
  • O. Fernandes
  • J. Abrantes


INTRODUCTION-Basketball shooting is the most important skill of the game Its teaching methodology is based on permanent adjustment of theoretical sentences of performance and individual characteristics. Development of basketball players needs talent but also technical qualities which is the reason why youngsters must know the basic principles of technique However, ball size, basket height and court dimensions are three variables which can affect the learning process of basketball shooting (Skleryk , 1985). The purpose of the present study is to analyse the effect of ball size on some mechanical parameters of free throw shooting, as performed by eight fourteen-year-old basketball players Two ball sizes were used regular size ball (613 gr weight, 74 cm perimeter) and adapted size ball (608 gr weight, 76.5 cm perimeter). Two video cameras were utilized to recover the videographic material on frontal and lateral views of shooters Three free throws of each player were digitalized and analysed with BIOSIST Based on Satern (1989), six mechanical parameters related to shooter segment were analysed on ball release (shoulder angle, elbow angle, wrist angle, hand height, linear hand velocity and hand angle) The determination of maximum elbow flexion occurring during shooting was another goal. Also, displacement of the centre of gravity and its relationship with support surface was investigated RESULTS-Mean and standard deviation of each parameter per trial digitalized were selected. Higher values of height and angle release were obtained with adapted size ball. It appears that the regular ball needs an increase of linear hand velocity in shooting Differences between intersegmental angles reveal a general tendency for the shooter to employ more force in regular-ball than in adapted-size-ball. Results show a higher flexion of elbow and a higher release elbow angle when the player shoots with a larger ball. Release angle wrist appears less with regular ball which indicates that more work is produced by the shooting hand with adapted-size-ball. Displacement of centre of gravity on the vertical plan was the most significant difference. The difference between initial instant of shooting and the ball release instant is 0.16 (+/-0 12) m with smaller ball and only 0.07 (+/-0.03) m with a larger ball. CONCLUSIONS-Despite the small differences in the quantitative results, this probably indicates that young players transfer lesser energy on regular-ball than on adapted-size-ball. This leads up to the hypothesis that the adaptation of ball size to particular characteristics of each age scale will create better conditions for young players to learn the correct principles of shooting technique REFERENCES Satern,M.;et al. (1989); The Effect of Ball Size and Basket Height on the Mechanics of Free Throw; J. Mov. SI.; 16; 123-137.