PROBLEM TO BE SOLVED: To widen the movable range of the upper arm and assist the holding of the upper arm within this wide movable range. SOLUTION: The first axis is extended in a substantially horizontal direction and is provided near the end on the base side of an upper arm arm, and the second axis is extended in a substantially vertical direction at a position different from the first axis. The rotating unit holds the substantially rod-shaped upper arm arm rotatably in the substantially vertical direction and rotatably in the substantially horizontal direction. Of the outer peripheral surface of the first pulley, one end of the cord-like body is provided on the elastic body, the other end is provided on the tip side of the first axis of the upper arm arm, and the position in the height direction is higher than the first axis. It is wound on the side opposite to the upper arm arm, and is wound on the upper arm side of the outer peripheral surface of the second pulley whose height position is lower than that of the first axis. [Selection diagram] Fig. 1【課題】上腕の可動範囲を広くし、この広い可動範囲内において上腕の保持を補助することができる。【解決手段】略水平方向に延設され、上腕アームの付け根側の端近傍に設けられた第１軸と、第１軸とは異なる位置に略鉛直方向に延設された第２軸を有する回動ユニットにより、略棒状の上腕アームは、略鉛直方向に回動可能に保持されるとともに略水平方向に回動可能に保持される。索状体は、一端が弾性体に設けられ、他端が上腕アームの第１軸よりも先端側に設けられ、高さ方向の位置が第１軸よりも高い第１プーリの外周面のうちの上腕アームと反対側に巻き掛けられ、高さ方向の位置が第１軸よりも低い第２プーリの外周面のうちの前記上腕アーム側に巻き掛けられている。【選択図】図１
