An analysis of 144 sports accidents of 275 tennis players in Switzerland (203 men, 72 women) showed fractures of bones in 5,5% open wounds in 14,5%, torsions in 33% and other injuries in 47%. The head was injured in 9,5 and the legs in 76%, the arms in 11,5% and the trunk in 11,5%. Two fifth of all leg injuries were on the left side, three fifth on the right side. The arms were hurt in 98% on the right and only in 2% on the left side. Causes of accidents were in 21% slipping on wet ground, in 17% related to the rackets, in 33% a too speedy start with damage to muscles and tendons, in 14% stepping on tennisballs lying on the ground. A tennis sport accident required an average of 35,8 days of treatment by a medical doctor and an average of 0,7 days of clinical treatment. Already 33% of the men and 26% of the women suffered from the so called "tennis-elbow".