<p>D played violin and piano. She was also a tennis player and a ballerina. She had some knee injuries from tennis and ballet, but neither interfered with her hands and her ability to play violin or piano. I don’t consider tennis a contact sport, though.</p>
<p>Besides the concerns with potential injuries, as they get older and get more serious about a discipline, it often comes down to conflicts in scheduling and time management. For a younger student I wouldn’t worry about it and allow them to explore various interests.</p>