I am not a cat experienced person, but I found a website, maybe useful for you:
"cat friendly clinic". They store a lots of videos about cat handling (I assume more for assistant staff and vets).
There is one video about the "Towel wrapping a cat". Additionally, there is a pictured instruction (in German language) on this Vet's Website (where I took the picture below, showing the first 4 steps of 10).
German to English:
Place your cat in the middle of the towel, with the towel extending about about 11/2 of a handwidth away from the cat's front. You should optimally place the cat laying on the towel, rather than sitting up straight. This result is usually achieved by applying gentle, but constant pressure on the cat's back with your hand and forearm - please give your cat as much time as it needs!
Pull the front edge of the towel over your cat's forelegs.
Put the towel around your cat's neck.
Hold the towel tightly together on the nape of the neck with one hand, so that your cat cannot move its forelegs over the towel.
I assume, if one uses this method, the power of holding the cat would not be this big, as without towel, and additionally the pressure is shared equally over all parts of the cat, not accumulate and injuring one part (for example the belly).