A passive movement deivce for exercising a patient's joint is provided. The device includes a resilient foam section and a casing enclosing the foam section within a sealed chamber. The patient's joint is held in position relative to the sealed chamber by a suitable retainer. A vacuum pump is operatively connected with the sealed chamber to selectively provide application and non-application of a reduced pressure, i.e. below atmospheric, to the sealed chamber. The application of the reduced pressure causes the foam section to collapse thereby exerting a force on the joint which causes the joint to move or bend from a predetermined position. The non-application of the reduced pressure to the sealed chamber causes the foam section to expand thereby exerting a force on the joint which causes the joint to move or bend toward the predetermined position.