In this study, an insole-type ground reaction force (GRF) measurement system using a load cell was manufactured and configured as a system that can measure joint angle and GRF, when walking in conjunction with a commercialized inertial sensor. The data acquisition device was used to acquire synchronized data, between the inertial measurement unit (IMU) sensor and the load cell insole. A three-dimensional motion analysis system comprising six infrared cameras and two ground reaction forces, was used to check the accuracy of the gait measurement system, comprising an inertial sensor and a load cell insole. The motion and force data were acquired while performing five times six-meter walking test by five young adult male subjects (Age: 26.0±1.8, Height: 171.4±6.8 cm, Weight: 62.2±10.8 kg). It was measured and as a result of comparing the calculated sagittal joint angle with the vertical GRF, the sagittal lower extremity joint angle correlation coefficient (Pearson’s r) was 0.40 to 0.94, and the vertical GRF to be 0.98 to 0.99. It is necessary to upgrade the joint angle calculation algorithm through future research. Additionally, the possibility of clinical application for actual stroke patients will be reviewed.
This study was to compare a domestic comfort shoes to the popular import(SAS<SUP>®</SUP>) to gain a better understanding in biomechanical characteristics for shoe design for the elderly. For each shoe type, morphologic dimensions, shock absorption, and flexibility were assessed. From subjects(n = 20, 72.4±5.5 years, 67.7±7.9 kg), mean peak pressure(MPP) and contact area(CA) at the plantar surface were analyzed. The domestic shoes reflecting anatomic contour of the plantar surfaces of Asians resulted in wider CA(by 30.4 cm²), higher shock absorption(by 2.4%) and stiffness(by 0.5 N/mm) than the import. With the domestic shoes, significantly less MPPs were found at the forefoot(by 42~49%) regions(p < .05) and higher CA was noted additionally at hallux and lessor toes(by 26~63%). More anatomically-contoured insole and favorable mechanical characteristics may help reduce the plantar pressures more effectively and more evenly, especially across the central forefoot and midfoot regions of the plantar surface, especially for the design of the comfort shoes for the elderly.