Here is the patent
There is more than one problem with recoil.
As you said there is the acceleration on the parts of the body.
There is the peak pressure on the skin. That is why large recoil pad areas, and recoil pads compliant to people shape, help.
Anecdotally, I have spoken with two guys over the last 15 years of going to gun shows, that just got detached retinas from recoil.
When my father designed the M55 about 55 years ago, they put acceleration on the barrel and used what passed for storage scopes back then. Force looked like a square wave.
The feature of parabolic tapered hydraulics is that the force is constant. If a hot load is fired, it is a larger constant, but the force is constant over the recoil stroke.
When I was just turned 5 years old playing in the water, I could not figure out how the water knew that the air was inside an inner tube. I lacked Archimedes' concept of density.
When I was 55 years old and looked at my father's hydraulic recoil mechanism, I could not figure out how a cylinder knew how much force to resist at each point. I did not see that the orifice area is changing and the oil velocity is changing.