Effect of a five-toed minimal protection shoe on static and dynamic ankle position sense

The main aim of this study was to test the hypothesis that the VibramFivefingers model, with its minimal structure, cushioning and finger separation, allows a more accurate estimate of static and dynamic foot position compared to wearing a standard cushioned running shoe.

Static ankle joint position sense was assessed in the sagittal and frontal plane by asking fourteen healthy experienced amateur runners to estimate the perceived direction and amplitude of a support slope surface board placed under their right foot while standing. The dynamic measures were performed with the subjects running on a treadmill at 12 km/h and asking them to evaluate the treadmill surface slope. Two footwear (Fivefingers and a cushioned protective running shoe) and the barefoot condition were compared.

Plantarflexion, dorsiflexion, eversion and inversion movements were underestimated in all the experimental conditions. In the static trials there was significantly more angle error underestimation (P<0.05) with the running shoe, while no significant differences were found between Fivefingers and barefoot condition. While running, the treadmill surface slope was significantly better estimated with Fivefingers than in the other two conditions (P<0.05).

The data support the assumption that with Fivefingers is more likely to get a more correct estimation of the surface slope while standing and running compared to using a standard cushioned running shoe. The finding that the cushioned shoes significantly impair foot position awareness compared to less structured shoes is consistent with the results of some previous studies on healthy and unhealthy subjects.