The purpose of this paper is to consider the mechanism of shoulder girdle injuries. Rugby is a contact sport which may be one of the most dangerous sports. We examined the charts of the Sugadaira summer clinic, which is open during the summer season. Every summer, at Sugadaira highlands,750 teams get together and practice for the autumn league matches. Most of the injured athletes visit our clinic. In 1988 and 1989, we treated 1,754 rugby players, of which there were 242with shoulder girdle injuries ( 13.7% ). There were 75 Glenohumeral dislocations or subluxations,69clavicular fractures,43 injuries of the acromio-clavicular joint and 7 sterno-clavicular joint injuries. The average age of all the patients was 18.4 y. o., but in the clavicular fracture, the average was 17.4 y. o. There were 123 forward players and 112 back players, The most frequent cause was tackling ( 69.9% ). We did some research by questionnaire about past injuries of the rugby players. A half of the players ( 44.5% ) had previously injured their shoulder girdles, and 13.1% of the players thought their shoulder injuries were the most severe injury. The shoulder girdle is one of the most vulnerable regions in the human being. Strong force in rugby sometimes causes clavicle fractures and sometimes A-C separations and sometimes injuries of the insertion of the trapezius muscle.
