Actions: Sit up, back extension, knees to chest, hip extension.
Benefits: The Back and Abs exercises the superior and inferior end of the long rectus abdominus muscle of the stomach wall in addition to the hip flexors and the erector spinae muscles of the lower back.
The sit up motion contracts the upper end of the stomach wall whilst the knees to chest action strengthens the lower end of the stomach and the pelvic floor. A back extension (hyperextension) movement then follows the sit up.
The Back and Abs effectively strengthens and flattens the stomach particularly the lower abdomen, mobilising the hip joint through a functional range also improves hip, knee joint mobility and lower back strength.