PROBLEM TO BE SOLVED: To accurately calculate an external force applied to a joint part of a subject.SOLUTION: An external force detection device 10 comprises a displacement member, an application part, a first acquisition unit 12B, and a first calculation unit 12C. The displacement member is displaced in response to the bending of a joint part of a subject. The application part applies a load to the subject. The first acquisition unit 12B acquires the displacement amount of the displacement member when the load is applied to the subject. The first calculation unit 12C calculates the external force to act on the joint part when the load is applied, on the basis of the displacement amount.SELECTED DRAWING: Figure 4【課題】被検の関節部に加わる外力を精度良く算出する。【解決手段】外力検出装置１０は、変位部材と、付加部と、第１取得部１２Ｂと、第１算出部１２Ｃと、を備える。変位部材は、被検体の関節部の屈曲に応じて変位する。付加部は、被検体に荷重を付加する。第１取得部１２Ｂは、被検体に荷重を付加したときの、変位部材の変位量を取得する。第１算出部１２Ｃは、変位量から、荷重を付加したときに関節部に作用する外力を算出する。【選択図】図４
