I am trying any help would be appreciated! !!

[Bforkum]

I have a duckling he is about a month old and walks on what I would think is his elbow and both of his feet are curled in I have him in a homemade sling in my room. We did have him outside for about a week thinking if he had more space he would fix himself but to no avail. We have mixed Niacin in his water as I read that if he doesn't have enough Niacin it can cause foot issues. All of our other ducks are fine and they all came from TSC. I have never raised ducks before please help!!!!!