Possibility of progress of throwing ability on adult females

The purposes of this study were to clarify the possibility of progress of throwing ability on adult females, and to examine effective instructional methods of throwing. Twenty-four female students who had no special experiences of motor learning of throwing were divided into three groups; two training groups (WI group: throwing exercise with verbal instruction and demonstration, and NI group: throwing exercise without instruction) and one control group. Training was carried out three days per week for four weeks. Measuring physical fitness and analyzing throwing motions were performed before and after the training period. In the WI group, throwing distance increased significantly from 24.38 m to 30.38 m. Actions of arm and legs during preparatory phase of throwing were changed, consequently factors of action at starting of main phase of throwing were also changed. It seemed that these changes leaded to faster forward rotation of shoulder during main phase of throwing, skillful whip-like action and wrist action. In the NI group, throwing distance increased from 24.67 m to 27.17 m insignificantly. Remarkable changes of throwing motions were not recognized except for the increase of range of shoulder rotation. It is concluded that throwing distance and throwing motion are changed remarkably by throwing exercise with proper instructions of technique.