Sorry to hear that. As we get older it especially important to take precautions. Yes. kick backs came be bad. I always pull the rope until the engine reached the compression stroke then give it pull. Even small engines like grass trimmers, small chain saws can kick back. But, the smaller ones usually don't hurt you. Notice I said usually?. Larger engines like your 12hp with large piston and weight can break even arms. Big old chain saws use to be really bad, new engines with compression releases usually iliminates kick back problems.

Ouch, felt that one kick. Hopefully that doesn't mess up your spring plans.