DISCUSSION
The GMFM is commonly used to measure changes in
gross motor function as a result of horseback riding therapy. Previous studies have used the total or dimension scores of the GMFM-88 more often than the GMFM-66. Repeated measures analysis among participants demonstrated significant gains in GMFM-88 scores after horseback riding therapy in most published studies. In contrast, two randomized controlled trial (RCT) studies did not demonstrate any significant gains in the GMFM-88 or GMFM- 66. In our study, significant gains in the GMFM-88 and GMFM-66 were demonstrated in both groups. In children with CP, the most rapid improvements in GMFM scores occur during the first 4 years of age, with children reaching a plateau between 5 and 6 years, depending on the severity of their disability. A proportion of children in each group were aged from 3 to 7 years, making it possible that gains were naturally occurring. In the present study, however, the significantly greater gains in GMFM-66 score and dimension E of GMFM-88 in the hippotherapy group suggest the beneficial effects of hippotherapy on gross motor function.