The relationship between forefoot position, plantar pressures and rearfoot kinematics during the stance phase of gait

At the cornerstone of this research was the theory that structure dictates function. In foot research, the influence of the forefoot on foot and lower extremity biomechanics has not been adequately studied. The purpose of this research was to demonstrate a relationship between forefoot position and four separate dynamic variables, including, medial midfoot pressure-time integral (MMPTI), medial midfoot peak pressure (MMPP), rearfoot eversion excursion (RFEE), and average rearfoot eversion velocity (RFEV). The underlying hypothesis was that forefoot position would be able to predict each dynamic variable due to the compensatory action of the midfoot for forefoot position.; Sixty-four cases (feet) were studied (N = 64, age = 26.8 ± 8.8 yrs, ht = 162.5 ± 9.5 cm, wt = 75.7 ± 21.8 kg). Static measurements of forefoot position, rearfoot eversion and navicular drop were taken by the primary investigator (KRB). Plantar pressure measurements were taken using the EMED pressure platform system (Novel Inc, Minneapolis, MN). Three-dimensional kinematic data for the rearfoot were collected using the Vicon system (VICON, Oxford Metrics Ltd, Oxford, England). The relationship, using a Pearson (r) correlation, between forefoot position and each dynamic variable was studied. The ability of the forefoot to best predict each dynamic variable was assessed using regression analysis. Finally, the mean differences among each dynamic variable were analyzed when the forefoot was sub-categorized into three groups dependent on forefoot position.; The relationships between forefoot position and each dynamic variable were found to be related and statistically significant (FF vs MMPTI: r = .55, p = .001; FF vs MMPP: r = .59, p = .001; FF vs RFEE: r = .65, p = .001; FF vs RFEV: r = .54, p = .001). The forefoot was the best predictor for each dynamic variable except one (MMPP) where navicular drop was a better predictor. The differences between FF categories and MWTI were significant between the low and high groups and the neutral and high groups; however, there was no statistically significant difference between the low and neutral groups. This may have been an issue of power. The differences between FF categories and MMPP were statistically significantly for all categories. The differences between FF categories and RFEE and RFEV were different between the low and high groups and low and neutral groups but not the neutral and high groups.; These findings suggest that forefoot structure plays a significant role in the prediction of MMPTI, MMPP, RFEE and RFEV. Further research should continue to assess the role that the forefoot plays in foot and gait biomechanics.