i have a pair of asterisk knee braces in size large that were given to me. i have measured my leg and according to your charts i should be a medium. but if i put a liner between my leg and the brace i can do them up nice and tight. but my concern is will they still work properly and help to prevent injury as there is play from side to side where my knee sits. if these are no good is it possible to make them into size medium or do i need a new set.