BackgroundThe great variability of viola dimensions is known. Contrary to the violin, a lack of scientific knowledge remains on how dimensions, positioning, and biomechanical parameters contribute to the high incidence of medical complaints in violists.AimsThis project investigated how an instrument’s dimensions affect objective and subjective levels of muscular effort in a player’s left hand and arm, together with the instrument’s position and biomechanical parameters.MethodsIn a laboratory set