Patent ID: 7824317

Claim:
A machine for training abdominal and lumbar muscles, said machine comprising a base plate, a flat movable body to be held between a user's knees, said movable body being swingably mounted about a fixed pivot point on an upper surface of said base plate, said movable body being movable towards and away from said upper surface of said base plate on opposite sides of said fixed pivot point, said movable body being movable in opposite directions beyond a plane extending normal to the base plate and normal to a longitudinal axis of the base plate, a self-weight pressing plate, the base plate being rotatably mounted on a center of said self-weight pressing plate with respect to a lateral axis of said self-weight pressing plate, the user lying supine or sitting on the self-weight pressing plate, and means for loading a resistance force to the movable body in a swinging direction, said means being interposed between the movable body and the base plate for turning a user's lumbar while inclining the user's knees to the left or right with the user holding the movable body between the user's knees so that when a user lies supine or sits on the self-weight pressing plate in a state where his/her knees are bent and his/her soles are grounded on the self-weight pressing plate, the movable body is at a position where the knees hold the movable body therebetween.