The aim of this study was to identify the effects of joint mobilization intervention combined with exercise on range of motion (ROM), pain intensity, and functional performance in adolescent baseball players with internal impingement syndrome of the shoulder. METHODS: The subjects were 30 adolescent baseball players diagnosed with internal impingement. Ten subjects were randomly assigned to each of 3 groups: Group 1 (exercise only), Group 2 (joint mobilization combined with exercise), and Group 3 (rest-only control group). Three weekly interventions were given for 4 weeks (the control †Corresponding Author : Yeon-Ki Choo