Design criteria for rigid rocker shoes.

In this study nine different rigid rocker shoe designs were tested in 17 symptom-free male subjects and compared with the control condition of a flexible, non-rockered extra-depth shoe with the same flat insole. Effects of both rocker height and axis location were explored. Peak pressure was reduced at most forefoot locations by rocker shoes, but increased in the midfoot and heel. Axis location was found to have an important effect, particularly on hallux pressures. On average the best axis location for reducing metatarsal head (MTH) pressure was in the region of 55-60% of shoe length, while for the toes it was 65%. There was a mean trend towards optimal reduction of pressure in one of the rocker shoe conditions at each anatomical location, but the axis position for this optimal placement was variable across subjects and anatomical locations. While most configurations of the rocker shoes were superior to the control shoe, no single configuration was optimal for all subjects at all sites or even for all subjects at the same site. Therefore, some form of plantar pressure measurement in conjunction with gait training to ensure correct use of the rocker shoes would appear to be essential if the pressure reducing effect of the rigid rocker bottom shoe is to be optimized.