Pom pom crab dying?

[olesalty]

Thursday night my girl said she had to flip the little guy over and help him to the rocks. She said his legs looked funny. Looked later and couldn't find him to get a better look. Came home from work Friday to see it out upside down again. Upon inspection it appears his back two legs were bent up not down. Like his legs were broke. Not sure how to explain. When he walks backwards he falls back upside down with these legs bent up. An
yhow placed him in a breeder box to monitor him. Is it on its way out? Have had him for a little more than a year.