A descriptive and comparative study of the traditional and spin goalball throw related to ball velocity
The purpose of this study was to describe and compare the game and throwing variables of the traditional versus spin throw in goalball to determine their correlations to ball velocity. Twenty-nine goalball athletes (17 men, 12 women) competing at a United States Association of Blind Athletes Regional Goalball Tournament were recruited to participate. The following data were collected and described for both the traditional and spin goalball throw: (a) descriptive analysis of game statistics and throwing tendencies during competitive play through visual observation, (b) identified phases of movement for the goalball throw and duration in each phase was determined through visual observation of a 2-D video analysis, (c) Pearson correlation identified any relationships between ball velocity of each type of throw and physical/motor components (flexibility, strength, power, and balance), and (d) 2 x 2 ANOVA determined if any differences were found between gender and type of throw. Results indicated a spin throw was observed more in men (42%) than women (1.5%) in tournament play. Men throw the goalball at faster velocity than women for both the traditional and spin throw. Three phases of movements for the goalball throw were recognized: (a) preparatory, (b) approach, including the wind-up and the delivery, and (c) follow through: no strong correlations were found between ball velocity and the duration in each phase of movement in either types of throw. A significant interaction was found between gender and the two types of throws (F)1,8) = 33.17). Post hoc test determined that gender explained the interaction. A significant relationship was evident between the fitness-ball throw (seated and standing) and the ball velocity of the traditional (r = .77 and .78 respectively) and spin throw (r = .84 and .82 respectively). Additionally a significant relationship was reported between ball velocity of the traditional and spin throw and vertical jump (r = .72 and .77 respectively). Conclusions of the current study suggest that coaches should integrate practices of the spin throw for men and women goalball athletes in training routines. Resistance training programs could be utilized to increase sports performance of the goalball throw. Future investigators should build on this foundational research and conduct clinical 3-D kinematic and kinetic analysis verifying phases of movement, elements of movements, and parameters that affect the velocity and accuracy of various types of goalball throws.