It doesn't look like bumblefoot from your pictures, but below are some good links with pictures of bumblefoot and instructions for treating it. Is there any swelling in the joints?
http://www.the-chicken-chick.com/2011/07/bumblefoot-causes-treatment-warning.html
https://www.backyardchickens.com/t/236649/bumblefoot-surgery-with-pics-and-how-to
http://www.hobbyfarms.com/livestock-and-pets/how-to-treat-bumblefoot-in-chickens.aspx
http://www.the-chicken-chick.com/2011/07/bumblefoot-causes-treatment-warning.html
https://www.backyardchickens.com/t/236649/bumblefoot-surgery-with-pics-and-how-to
http://www.hobbyfarms.com/livestock-and-pets/how-to-treat-bumblefoot-in-chickens.aspx