The body support chair for the physically challenged and disabled comprises a frame supporting an articulated structure comprising a back, a seat, a foot rest (33) supported by two uprights and means for holding the legs, at least in part immovable. The holding means comprise: two cross-members, each fitted on an upright (27) of the foot rest for extending into a working position (T) towards the front of the chair and provided in the front part with fastening means (80) arranged in the working position (T) at a corresponding distance from the upright (27); and an immovable front support element for the user's two legs, fitted on the fixation means (80) of the cross-members, in such a fashion as to extend between the cross-members.