Participants ( n = 102 ) were matched in pairs and randomized to intervention ( Mitii for 20wks ; 26 males , mean age 11y 8mo [ 2y 4mo ] , Manual Ability Classification System level I = 11 , II = 39 , III = 1 ) or control ( standard care ; 25 males , mean age 11y 10mo [ 2y 5mo ] , Manual Ability Classification System level I = 13 , II = 37 ) .