Sp braces were made of plastic plaster for athletes who had suffered from shoulder and elbow problems when throwing. Its shape was spiral and its function was to keep the arm in the scapular plane. The purpose of this paper was to examine the efficacy of this SP brace. Thirty-nine college baseball athletes were checked for pain, tenderness, strength at a preseason medical checkup. Then they wore an SP brace and were asked about the suitability of the SP brace at throwing, They were divided two groups, A and B. Group A did not their throwing disturbed, however group B had their throwing disturbed when wearing an SP brace. The checkup data were examined statistically and compared. A group had nineteen patients. Four athletes had shoulder problems and three had shoulder and elbow problems. B group had twenty. Six athletes had shoulder problems and nine had shoulder and elbow problems. There was a statistical difference between groups A and B. Many factors participate in throwing injuries. Skill was one of the most important factors. If the arm was kept in the scapular plane or at the zero position during acceleration phase, the mechanical stress at the shoulder and elbow joint was reduced. This SP brace was effective to keep the arm in the scapular plane and educate the throwing mechanics.
