tokens: Significant reductions were noted in vertical GRFs per newton of body weight exerted at 10 % ( P = 0 . 0009 ) and 20 % ( P = 0 . 0383 ) of stance phase and in anteroposterior GRFs exerted at 10 % ( P = 0 . 0009 ) and 50 % ( P = 0 . 0033 ) of stance phase when ambulation was compared with and without the orthotic device .