This is an article from Bass Musician Magazine by Igor Saavedra. Though he is writing about bass guitar he has an interesting perspective on the mental/physical aspect of playing and injury
http://bassmusicianmagazine.com/2012/07/getting-rid-of-tendonitis-for-good-by-igor-saavedra-part-1/
http://bassmusicianmagazine.com/2012/07/getting-rid-of-tendonitis-for-good-by-igor-saavedra-part-1/