柔軟ポリマー曲率センサによる歩行中の足部構造変化の計測

抄録

Dynamic deformation of foot structure has been measured mainly by fluoroscopy or 3D imaging using skin markers. However, these methods require large, expensive equipment, and their measurement range is very narrow. Because of this drawback, the dynamic deformation of foot structure during steady walking cannot be measured. To measure the dynamic deformation of foot structure during steady walking, we used a flexible polymer curvature sensor (2.0 mm×20.0 mm) that is capable of convert its vending curvature to voltage. This sensor was attached to the first tarsometatarsal joint, which is a part of the medial longitudinal arch;this joint consists of the first metatarsal bone and the medial cuneiform. Twelve healthy adult males (age, 22.2±1.0 years) participated in the measurement experiment, and the flexible polymer curvature sensor was attached to their skin at the first tarsometatarsal joint. The subjects were asked to walk barefoot on a treadmill. The measurement voltage, i.e., the deformation of the first tarsometatarsal joint, showed large individual differences in the curvature changing pattern and amplitude. However, we confirmed that the deformation of the first tarsometatarsal joint changed cyclically according to the gait cycle. Moreover, the amount of deflection at the center of the attached curvature sensor was increased to 0.29 mm on average, as estimated from the range of curvature changes.