I agree equiniphile, he did get gelded about 2 weeks ago though. If he were mine I would give him a bit more time to heal and them put him out with some gentle mares or geldings just to run and detox from the bad handling he has had. Horses NEED to run, they NEED freedom. Its hardwired into their brains to move up to 30 miles or more a day to find food, escape predators etc. Its not fair to a horse to pen him in a little stall day after day and not allow him to run. He desperately needs it! His pain from his gelding will limit how much and how fast he runs, but walking around is going to help reduce his swelling which is quite a bit from the video you posted.
Spent a whole hour today laying in a pasture, waiting for a sparkling vampire to show up. Alas, I woke up and looked over, only to find a mound of horse crap. Sigh.