cut protection sleeves for power tools
The guard that came with the grinder properly adjusted would be the best protection. The next is using the tool properly so the tool is pulling away from body parts not at them. Would a Kevlar shield or sleeve help to reduce damage to the body, Yes but only if the protective device is covering the area that the tool comes in contact with. I have seen a contractor get injured when using cutting disk and forcing it so when the blade broke it grabbed and took a big chunk of flesh if he would have had the guard on he probably would not have been injured.