Gymnastic apparatus for exercising abdominal muscle, has flexible strip that exerts return force on curved backrest and on back of gymnast when gymnast releases pressure of his back on backrest

摘要

The apparatus has a curved backrest (5) moving back and forth around a pivot (7) under the pressure of back of gymnast (G). A flexible strip (2) partly opposes backward movement of the backrest caused by the pressure. The strip exerts a return force (P) on the backrest and on the back of the gymnast when the gymnast releases the pressure of his back on the backrest. An independent claim is also included for a gymnastic method for exercising only the abdominal muscles.