Conventional instruments that improve pelvic distortion and sacroiliac movement have been performed in a supine or sitting position. Some of them did not have sufficient mobility. Provide an exercise assisting device that moves the sacroiliac joint in a lateral position. An example will be described in the left-side position. Place the upper right leg on the platform (1) in the lateral position and support the sacrum with the pad (2) that supports the sacrum, and the upper right leg is extended rearward in a passive manner. Since the lower left sacroiliac joint (9b) has a slightly opened rear surface, the sacrum (6) slides backward via the right hip joint (10a), and the lower left sacroiliac joint (9b) is movable. It is characterized by improving sex.骨盤の歪みや仙腸関節の動きを改善する従来の器具は仰臥位や座位にて行われていた。なかには十分な可動性が得られないものもあった。側臥位で仙腸関節を他動的に動かす運動補助器具を提供する。実施例を左側臥位で説明する。側臥位で台（１）に上側の右脚をのせ、仙骨を支えるパッド（２）で仙骨部分を支えながら、上側の右脚を他動的に後方に伸展させる。下側の左仙腸関節（９ｂ）は後面が僅かに開いた状態のため、仙骨（６）は右股関節（１０ａ）を介して後方に滑り、下側の左仙腸関節（９ｂ）の可動性を改善することを特徴とする。
