Hi
Hope he is not allergic to any medicine.. u must give him Tendocare once a day for 15 days at night..
Followed by an ayurvedic medicine.. Rumalaya forte two times a day for 1 month. Let me know the condition after 1 month, we might increase same medicine for few more days.
Next Steps
ask him to walk for 10-15 mins despite of some pain ( should not be severe) .
Health Tips
avoid heat around the joints... it might give him relief.. but it is not good for swelling.
Instead give him icing over the swollen areas ( 10 mins, but with caution as ice also creates burns like heat) this will help him