Abstract: Forces applied to cause flexion and extension movements of a joint of a subject (1) are detected by at least one force sensor (20a, 20b), and a joint torque for flexing and extending the joint is calculated based on the forces. Further, a joint angle of the joint of the subject is measured by a sensor (30). Then, a change with passage of time in each of the joint torque and the joint angle during flexion and extension movements of the joint of the subject is separated into a maximal extension position static phase, a dynamic flexion phase, a maximal flexion position static phase and a dynamic extension phase, and a muscle tonus feature amount is extracted from a relationship between the joint angle and the joint torque in at least one of the dynamic flexion phase and the dynamic extension phase.

Abstract: An electric soldering iron is made difficult to heat up at the front end of its grip. A metal pipe is inserted in the grip so that the pipe comes into close contact at least partially with the grip, with a gap formed between the outer peripheral surface of the pipe at its front end and the inner peripheral surface of the grip. The heat produced by the accumulator conducts through the pipe to the grip and disperses throughout the grip. Thus, the front end of the grip is less likely to heat up.