The Change of In-shoe Plantar Pressure according to Lever-point of Metatarsal-Bar

Objective: To find the most effective lever-point to manufacture the rocker-outsole. Method: Ten healthy men were participated. Metatarsal-bar, 12x1x0.5 cm, was clung to the outsole of shoes. In the first experimental-group, we set the center of the metatarsal-bar to an imaginary line which across the center of the 1st metatarsal head with that of the 5th metatarsal head. In turns, we experimented the other groups as moved the center of the metatarsal -bar 0.5 cm backwards, each naming 2nd, 3rd, 4th group. Plantar peak pressures were measured at T0 (whole foot), M1 (heel), M2 (midfoot), M3 (1st, 2nd metatarsal area), M4 (3rd, 4th, 5th metatarsal area), M5 (great toe), M6 (2nd, 3rd toe) and M7 (4th, 5th toe). Results: There was significant decrease in the peak pressure of in M3 the first experimental-group, which the center of metatarsal-bar was set to an imaginary line. Conclusion: In the first experimental-group, there was significant decrease in the peak pressure of M3. Therefore, the lever-point of rocker-outsole should be set to an imaginary line which connects the center of the 1st metatarsal head with that of the 5th metatarsal head.