PROBLEM TO BE SOLVED: To provide a knee joint treatment instrument that enables a user to easily perform operation such as bending of a knee joint in order to perform treatment of disorder of a knee joint such as the meniscus damage and at the same time prevent it.SOLUTION: A knee joint treatment instrument 100 is provided for enabling a user to place a knee and make a knee joint bend and stretch. The knee joint treatment instrument includes a placing member 4 having a substantially elliptic cross section and having a roundness on at least a knee joint placing surface of the cross section to form a knee back placing surface 4a, and a support base 3 having at least one strut 2 having a supporting unit 5 for supporting the placing member 4 through a turning shaft 6. The supporting unit 5 has a connecting structure continuously provided by a required number in the height direction so that the placing member may be turned centering on a turning axis line 7 as a turning axis and the installation height of the support base 3 of the placing member 4 may be adjusted. The strut 2 is set up to the base 1, and a turning regulation groove 8 for regulating a turning range of the placing member 4 is provided in the strut 2.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2018,JPO&INPIT【課題】半月板損傷等の膝関節の障害の治療と同時に予防するために使用者が膝関節の屈伸などの動作を容易に行うことができる膝関節治療器具を提供することを課題とする。【解決手段】使用者が膝を載置して膝関節を屈伸させるための膝関節治療器具100であって、略楕円形の横断面を有して前記横断面の少なくとも膝関節載置面に丸みを有し膝裏載置面4aとされている載置部材4と、前記載置部材4を回動軸6を介して支持する支持部5を有する支柱2を少なくとも1つ有する支持台3とを備え、前記支持部5は、前記載置部材が回動軸を回動軸線7を中心に回動可能で且つ前記載置部材4の前記支持台3の設置高さが調整可能なように、高さ方向に所要数連続して設けられた連結構造を有し、前記支柱2は基台1に立設され、前記載置部材4の回動範囲を規制する回動規制溝8を支柱2に備える膝関節治療器具。【選択図】図1