After 24 weeks , both pain and function improved in the ST , EX , ST+EX , and usual care groups ( mean ( SD ) -17 ( 27 ) , -20 ( 29 ) , -15 ( 27 ) , -19 ( 29 ) ; and -11 ( 19 ) , -12 ( 19 ) , -10 ( 19 ) , -11 ( 20 ) , respectively ) , without significant differences between groups .
