Abstract
The purpose of this study is to develop a system for measuring muscle hardness using an ultrasound imaging device. The system was applied to measuring muscle hardness before and after stretching. An ultrasound probe holder that has three force sensors was constructed. The holder could measure the force of the probe on the skin while acquiring an ultrasound image. Two images were obtained with and without a compression force of 1 kgf. Subjects were instructed to stand on a stretching board. Stretching was performed three times, and images were obtained again. The thickness of the muscle was measured from the image, and the strain was calculated. The Young's modulus of the muscle was calculated from the stress and strain. The Young's modulus decreased after stretching. It was concluded that the developed system could be applied to measuring muscle hardness.
