The effect of orthotic devices on freeway space.

After any orthotic device placement, there are three possible outcomes to the freeway space. The freeway space is either decreased, unchanged, or increased. The objective of this study was to determine what effect the placement of an orthotic device has on freeway space. Freeway space was measured in a group of 26 subjects immediately after placement of an orthotic device. In a second group of 26 subjects, freeway space was measured at least one week after placement of their orthotic devices. The freeway space was measured along the closing trajectory path during function. The number recorded was based on the actual measurement of the freeway space using a computer measuring device. Both sets of data were analyzed without taking into account other factors which may have influenced the freeway space. A Mann Whitney U test showed no significant differences between the two groups (Z = 0.027, P = 0.978 ). This study concluded that the thickness of an orthotic device does not necessarily increase or decrease freeway space.