744 MEP139 – The developed elastomeric elbow brace prevents valgus effectively without decreasing ball speed during repeated throwing

AbstractBackground Elbow joint disorders are common among adolescent baseball players. The survey of 5,768 players over 13 years showed that approximately 50% experienced elbow pain (The Japanese Society of Clinical Sports Medicine, 2005). Taping, and braces with metal hinges are prescribed, but they are not widely accepted due to skin damage and high costs.Objective The objective is to verify the effect of preventing valgus and ball speed by the elastomeric elbow brace.Design Quasi-experimental studySetting/Patients Ten healthy males experienced baseballInterventions The brace is made of Thermoplastic Styrene Elastomer (hardness 30°, thickness 5mm), which is a material that is self-adhesive, highly elastic (elongation rate: 500–1500%), and flexible. The brace has a shape in which materials are arranged radially in eight directions around the medial epicondyle of the humerus, and each part is stretched by 400%. 100 throws were done with and without bracing.Main Outcome Measurements Before throwing and after every 20 throws, the distances of the medial joint spaces were measured by ultrasound. The speed of the ball was measured by a speed gun. They were compared by paired t-tests. The significance level was less than 5%.Results These distances of the medial joint spaces were 4.7±0.2mm with bracing and 4.9±0.2mm without bracing before throwing, and 4.7±0.7mm with bracing and 6.2±0.7mm without bracing after throwing. The distances after throwing with bracing were much less than without bracing. There was no difference in ball speed with and without bracing.Conclusion Wearing the developed brace prevents valgus and maintains ball speed.