I believe it was @gevshiba who posted that FOS (flip over syndrome) is caused by a vitamin A deficiency. She said she feeds alfalfa or kale to cure and prevent FOS. Some of the vitamin supplements are also high in vitamin A and can help get the poults back to normal.
Actually, the vitamin deficiency hit at about 5 weeks. Flipping right after hatch, for my poult, was due to pipping the wrong end and getting stuck for so long. I did the container thing and he was on his feet after several hours.