I am dealing with a chicken with a gimpy leg too. Her leg wasn't all swollen, but what seems to be working for me is, putting her in a dog kennel or small room to rest. You can also crush an aspirin up and coat the meal worms with it. My chicken would only eat them thou, if I held her up, and put her beak in them, you can also boost her water with, save-A-chick electrolyte. Lastly, I wrapped her foot with a mixture of sauve, and arnica. Just mix it up, and tear some small strips of paper bag. Wet them and after applying the sauve mixture to the inflamed areas, cover them in the wetted bag strips. Finally wrap the strips in vet wrap, preferably no chew, that will help keep her from taking it off, and duck tape the wrap end down so she won't unwrap it. Some chickens get better in a few days, some take closer to a month. if she is taking longer, I would consider wrapping her foot. I haven't done any research on wrapping, but I know the wrapping strategy helped my horse recover form a stress injury quit quickly and my chicken seems to be progressing.
Hope this helps,
Avery