Advice to help a client who's a chiropractor

Hey y'all,

I train a chiropractor and he spends a large period of time each day in the position in the photo attached:

It's not him in the pic BTW.

Here's a video of the stance he assumes frequently: 

 

He feels it really takes it's toll on his body, particularly as he's a very good Iron Man competitor. 

Any exercises from the system that people could recommend?

P

I've had this done to me, after a spinal segment became stiff after a lot of gardening.

I've also performed mobilisations (much slower, not a quick manipulation like this) on people in prone position.

So performing techniques like this requires bracing in the anterior chain (musculature towards the front of the body) from waist up, and posterior chain (glutes etc) from hips down.

If he's an Iron man competitor he's also hunched over the bike a lot. These help a LOT: https://www.t-rack.com.au/

From foundation, ground rows and hinge rows (in a progression) would be good, as they require strength in the back of the shoulders and the ability to keep the trunk straight, and all of the handstand series mobility at least up to PE6.