I had an ex racehorse with check ligament injury, after box rest and time off started work slowly and felt it coming up again, my vet came out and told me to kaolin poultice it. Warmed kaolin up and put on very thick, wrapped in brown paper, bubble wrap and bandaged and left on for 5 days ( thought vet was bonkers at this point) gave her tiny turnout through day and brought in at night. 5 days later took off bandages and leg was like new. Don`t know if it was luck or what but would recommend it to anyone!!.
i had a livery come up to mine and her horse had an injured check ligament - he had undergone some surgury for it. he came up to my yard to live out for the winter - it did work wonders on his leg! the gentle constant exercise really did reduce the swelling! he was turned out with about 7 others - of mixed ages but as they all lived out - they used to just plod around the field - didnt go running around like racehorses! the fields are also really well draining so it was never to muddy.
his owner then started to lightly hack him in walk - and built it up from there - he now is still out on the showing circuit and still being placed!
i'd def mention it to your vet for their advice.