The purpose of this study was to determine the breaststroke timming of the movements of elbow, knee and forearm joints in the four swimming phases among selected university students. The subjects of the study were two national top swimmers, four trained and six untrained swimmers. They were sprinted 25m breaststroke with their maximum effort attached to water-proof electrogoniometers (elbow, knee and forearm). Swimming form was taken by a high speed cine camera operating at 48-64 fps, and synchronized by 4ch pen-oscillograph recorder. The magnitude of the angles for the flexion, extension, pronation and supination of elbow and forearm movements, and the flexion and extension of knee movements were measured by means of waterproof electrogoniometers. The angular velocity of elbow extension and forearm supination among the top and trained swimmers were significantly different from that of the untrained swimmers in the armstroke during at the pull phase. There was significant correlation coefficients between the angular velocity of elbow extension, forearm supination and the swimming velocity respectively. Moreover, the magnitudes of knee joint angle and angular velocity of knee joint among the top and trained swimmers, were significantly different from untrained swimmers. The timming of the armstroke and leg kick showed greater overlap among the untrained swimmers than among the top and trained ones during the P-R phase. The results indicated that untrained swimmer have already started leg recovery at the beginning of armstroke. It was suggested that during the recovery phase, the armstroke should be accerelated the amplitudes of knee joint angle be increased, and the leg kick be more accerelated in order to supply the propulsive force effectively in breaststroke. In conclusion, at the beginning of the catch of armstroke the timming of leg kick recovery of swimming beginner should be delayed.
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