Foot Arch Kinematics; Differences Between Barefoot And With Footwear

Abstract

INTRODUCTION: The relationship of athletes and footwear is important to sports performance. However, there is little information the effects of footwear on the foot arch kinematics which acts as a shock attenuator. The reasons include the foot is covered by sock or footwear; we cannot observe the foot motion from the outside. PURPOSE: The purpose of this study was to demonstrate the footwear effects on the sagittal plane kinematics of the medial and lateral longitudinal arch during single leg landing using cineangiography. METHODS: Ten healthy male and seven healthy female subjects participated in this study (males; age: 21.7 ± 3.4 y.o., height: 172.6 ± 6.8 cm, weight: 61.9 ± 6.0 kg, females; age: 22.3 ± 3.8 y.o., height: 167.8 ± 11.3 cm, weight: 58.3 ± 14.8 kg). IRB approved informed consent was obtained from all subjects. All subjects performed single leg landing from a height of 10cm with the knee extended under two conditions; barefoot and shod. Subjects were asked to stop and balanced after landing. All trials were recorded using cineangiography. Images were obtained at rate of 60Hz. Simultaneous vertical ground reaction force was measured using a force plate. Data were analyzed using graphic software. The sagittal plane motion of the foot arch was defined as the angular change and translational motion observed after landing. A paired t-test was performed to determine differences between barefoot and shod conditions. Significance was set at p<0.05. RESULTS: The angle variation of the lateral arch in shod condition was significantly smaller than that of barefoot (males; 5.1 ± 2.0° (shod), 7.9 ± 3.2° (barefoot), females; 5.7 ± 1.6° (shod), 11.5 ± 1.9° (barefoot)). On the other hand, the medial angle change did not have a significant difference (males; 2.4 ± 1.6° (shod), 3.5 ±3.3° (barefoot), females; 5.3 ± 1.7° (shod), 7.8 ± 2.1° (barefoot)). The maximum vertical ground reaction force was reduced in shod condition. CONCLUSIONS: This study suggests that footwear effects a change in the kinematics of the longitudinal arches during landing.