The Effect Of Two Custom Molded Orthotics On Plantar Pressure During Treadmill Walking

Abstract

PURPOSE The purpose of this study was to determine the effects of two custom molded orthotics on plantar pressures during treadmill walking at 3.0 mph. METHODS Twenty-three apparently healthy individuals volunteered for this study. Subjects for this study were classified as having low arches and mobile feet. Inclusionary criteria included an arch index of ≤0.287 and a mobility rating of > 0.743. Plantar pressures (PP) were measured using the EMED Pedar in-shoe plantar pressure measurement system. Data were collected under two conditions: no orthotic (NO) and orthotic (ORTa and ORTb) at two different times (zero and six weeks). Subjects completed a total of three trials per condition during the initial data collection period. After data collection subjects were randomly assigned to one of two experimental groups (12 ORTa and 11 ORTb). RESULTS Statistical analysis revealed a significant initial increase in PP for the ORTa group of 25.9% (p=0.000) in the midfoot (MF), 10.9% (p=0.028) in the middle toes (MT), and 17.8% (p=0.000) in the little toes (LT) regions and a significant decrease in PP of 9.4% (p=0.004) in the medial heel (MH) and 10.8% (p=0.001) in the medial forefoot (MFF) regions. Similarly, initial analysis revealed ORTb use increased PP 22.9% (p=0.000) in the MF, 10.5%(p=0.025) in the MT and 24.5% (p=0.000) in the LT regions, but decreased PP 16.3% (p=0.000) in the MH,15.7% (p=0.000) in the lateral heel (LH), 14.6% (p=0.003) in the MFF, 26.6% (p=0.000) in the central forefoot (CFF), and 17.1% (p=0.001) in the lateral forefoot (LFF). At six weeks, following an accommodation period, the ORTa group showed a significant increase in PP of 26.9% (p=0.014) in the MF, 32.1% (p=0.001) in the MT, and 30.9% (p=0.017) in the LT regions and a significant decrease in PP of 22.2% (p=0.006) in the MFF region. The ORTb group at six weeks showed a significant increase in PP of 29.0% (p=0.001) in the MF and 35.6% (p=0.01) in the LT regions and a significant decrease in PP of 14.7% (p=0.036) in the LH, 21.7% (p=0.049) in the MFF and 47.7% in the CFF regions. CONCLUSION Although both orthotics altered plantar pressures, neither corrected gait in such a way as to optimize plantar pressures in this population, at this walking speed.