Boat depression

When lying on the back, the front abdominal wall is significantly lower than the level from the costal margin to the pubic bone. It is called abdominal retraction. The total abdominal depression refers to the diffuse and significant depression of the front abdominal wall when lying. When the disease is serious, the front abdominal wall is almost close to the spine. The costal arch, iliac crest, and pubic symphysis are revealed abnormally.