If you're wondering what this pregnant belly business is about, you have to know that mpreg (or male impregnation) is another popular trope of knotting. And while that deserves a whole post on its own (it exists both inside and outside the world of knotting and fan fiction) its connection to knotting can't be denied.
The term levocurvature of the lumbar spine means leftward deviation of the lumbar spine. The curvature is greatest (apex) at l4. Dextrocurvature or dextroscoliosis would refer to a rightward deviation of the spine. Would you like to video or text chat with me?
On average, an avulsion will occur every time the bed of a river channel aggrades enough that the river channel is superelevated above the floodplain by one channel-depth. In this situation, enough hydraulic head is available that any breach of the natural levees will result in an avulsion.