Strengthen hind end?

Hey, so as many of you may know I just rescued/bought a beautiful Belgian. We're all pretty sure he's got EPSM, vet said it wasn't even worth testing she's so sure. He's lost a great deal of weight and a ton of muscle, almost completely on his hind end and topline. The most important thing is getting weight back on, which I'm doing well with. But he needs exercise, precisely exercises that will help his top line and hind end. He has string halt too, which my farrier 'prescribed' exercise for.
I know hills and poles are great, but I've got neither. So far I've been taking him for 20 minute walks around my driveway (a big circle driveway) he gets very tired and starts lagging behind after about 10-15. Just walking. I also turn him out, after about an hour outside (even with hay) he stands at the gate and wants to come in. There is snow out there, which I had him walk through a bit today, as it makes him pick his feet up higher, but he kept tripping - so I went back to the driveway. It's not icey, he's not slipping and it's soft, he just seems to stumble.

For reference this is what he looks like:

Or even helpful stretches that I could do?

I'm no bodyworker, but he looks sore in the hind end to me too, not just lacking muscle but tucked under...

Isn't he an older horse? That, with the combination of his being worked hard, may be arthritis too. His lack of stamina could be a combination of pain and lack of strength due to his muscle loss.

His diet was very lacking from what I remember. He needs quite a bit of time to get on a good, stable diet and build muscle. Go slowly and take baby steps. He will tell you what he is capable of. Dont' expect miracles. I think keeping him moving, nothing too complicated, is good for him right now.

If the vet thinks he has EPSM, diet change would hopefully help him. Since you want to increase the fat in his diet and do it slowly since he's in bad shape, I'd work with your vet as to how to start the process. Here is a link to Dr. Valentine. She also has books. You can also email her. She got back to me the next day and is wonderful.

Beth Valentine's Recommended EPSM Diets

Another good Dr. Valentine link:

Draft horse and mule health care

What you're going to discover is all these conditions are connected. They all share some of the same symtoms so it's hard to say he has more of a problem with one over the other. Your best bet is to get him on a full blown EPSM diet. The stringhalt is exacerbated by the lack of energy to the large hind muscles. Forcing him to even walk at this point is potentially more damaging than good. He is going to use lean muscle mass to fuel the muscle. If he is reluctant to do something, give him the benefit of the doubt that it's painful or he just doesn't have the energy to do it. 24/7 turnout wandering around the pasture at his own pace is what's best for the next month. Give him the month to train his muscles to use the fat as an energy source. One good part is the cold weather makes everything worse so it will get better.

I've had impressive results with acupuncture. The first session gets them moving more true and freely and with 3-5 total, I can get them on a once a year maintenance. My stallion loves the deep muscle stimulation (they hook the needles up to a power source). He is not a EPSM horse but had a pinched nerve and has weak hind end as a result.

He already looks better.

Left.....I have found recently, that I can't get the acupuncturist to even come if I don't have a diagnosis to start with. However, in OP's situation, vet did say he has EPSM...wondering if that would be sufficient without testing for her.....

I'm surprised that you need a diagnosis to receive acupuncture. Now an acupuncturist must be a licensed vet but it's always used as an alternative treatment much like acupressure or chiropractic manipulation. Minor "offs" that you can't put a diagnosis on are often great candidates for acupuncture.