A muscle contraction detection sensor (1) for detecting muscle contraction, which is arranged on a substrate (2) arranged to face a muscle to be detected, and arranged on the substrate (2) and pressed toward the muscles, respectively. The pressing member has two pressing members (3, 4) and at least two reaction force detection units (6, 7) for detecting the reaction forces received by the corresponding pressing members (3, 4). The first reaction member includes a first pressing member (3) and a second pressing member (4), and the reaction force detection unit includes a first reaction force detection unit (6) and a second reaction force detection unit (7). Including the reaction force received by the first pressing member (3) detected by the first reaction force detection unit (6) and the second pressing member (4) detected by the second reaction force detection unit (7). ), a muscle contraction detection sensor (1), which detects a contraction of a muscle based on a difference with a reaction force received by (1) or a change in a ratio.筋肉の収縮を検出する筋収縮検出センサ（１）であって、検出対象となる筋肉に対向配置される基板（２）と、基板（２）上に配置され、それぞれ筋肉に向けて押し付けられる少なくとも２つの押付け部材（３、４）と、それぞれ対応する押付け部材（３、４）が受ける反力を検出する少なくとも２つの反力検出部（６、７）と、を有し、押付け部材が、第１の押付け部材（３）と第２の押付け部材（４）とを含み、反力検出部が、第１の反力検出部（６）と第２の反力検出部（７）とを含み、第１の反力検出部（６）により検出された第１の押付け部材（３）が受ける反力と第２の反力検出部（７）により検出された第２の押付け部材（４）が受ける反力との差または比の変化に基づいて筋肉の収縮を検出することを特徴とする筋収縮検出センサ（１）。
