I have him for sale and this has been a concern to prospective buyers, however it does not interfere with his motion or balance. It did not affect him in the least but always made people comment. Herbally you could try some fenugreek tea in his feed. This is a good lymphatic clearer and also helps a little if there are fat metabolism problems. Fenugreek is usually available as small bullet hard yellow seeds, which can be made into a tea to be added to the feed or they can be sprouted and included in the feed.
Linseed oil is a great topical oil for any muscular damage.
It will give elasticity to too tight a tendon or ligament and retension any that are too tight.