The laxity of shoulder is one of main factors affecting shoulder lesions in athletes.
To measure the anterior-posterior laxity of shoulder, a stress machine was arranged because the ordinary rentogenographic measurement is not suitable. The measurement of the anterior-posterior laxity was done with athletes in several kinds of sports in which shoulder joints are mainly used. The result was compared with those from clinical examinations and stress rentogenography. Conclusions :
1. The anterior-posterior displacements of the affected side in baseball, volleyball and javelin players were significantly larger than that of the control side.
2. For the anterior-posterior displacement of the shoulder joint, baseball, volleyball and javelin players showed significantly larger values than truck runners as the control whereas significantly smaller values were found in water polo players.
3. There was no correlation between the anterior-posterior laxity and the inferior laxity.