EFFECT OF CUSTOM FOOT ORTHOTIC INTERVENTION ON 3-DIMENSIONAL LOWER EXTREMITY KINEMATICS AND KINETICS DURING RUNNING

Abstract

It is generally accepted that custom foot orthoses (CFOs) are an effective therapeutic modality in the management of lower extremity overuse running injuries. This being said, there is very little known about how this intervention mechanically produces positive clinical outcomes. Several previous studies have included subjects who exhibit within normal limits (WNL) maximum ankle eversion angle and have shown that CFO intervention has minimal effects on lower extremity kinematics. These studies employed a variety of inserts not necessarily manufactured by an accredited laboratory or designed by Rootian convention. PURPOSE To compare 3-dimensional (3-D) ankle and knee kinematics and kinetics with and without CFO intervention in a group of female runners who exhibit WNL maximum ankle eversion. METHODS This study included 10 recreational and competitive runners who exhibited a maximum ankle eversion angle <10 degrees eversion. Subjects performed 5 overground running trials with and without CFOs. During each running trial, 3-D kinematics and kinetics were collected from which ankle and knee, joint angles and moments were calculated. Ankle and knee kinematics and kinetics were compared for with and without CFO conditions using t-tests (p < 0.05). RESULTS The maximum ankle and knee 3-D joint angles did not significantly differ with and without CFOs. In addition, there were no significant differences in ankle and knee 3-D moments with and without the intervention. CONCLUSION CFO intervention did not elicit any significant changes in the 3-D kinematics or kinetics in the current sample of female runners. Intuitively, this is what would be expected given runners who exhibit WNL ankle eversion are not typically candidates for foot orthotic therapy. The findings of the current study suggest that further research should include subjects who exhibit excessive ankle eversion and the question is raised as to whether more stringent inclusion criteria need to be employed when studying the effect of CFO intervention.