US Patent 9168416 Abdomen exercise machine

An exercise machine applicable for strengthening a user's abdominal muscles is described. The exercise machine can include a base frame having a seat pad, a front leg and a rear leg. The seat pad can be elevated with the front leg and rear legs to provide round support. A mounting assembly may be rotatably mounted on the base frame over the rear leg. The mounting assembly can have at least one pivot joint. A backrest assembly can be movably coupled to the mounting assembly via the at least one pivot joint for swivel movements along the base frame. The backrest assembly can a backrest pad and handle bars. The handle bars can allow a user resting against the backrest pad to control the swivel movements while sitting on the seat pad.