I have both. The old one, and whole arm. I didn't buy under armpits. Unstable and dangerous to use. The old ppl one is for stability. Once my feet can hit the ground, I'll use the whole arm one. My friend lend the whole arm to me while I bought the old ppl one. I don't expect myself to move so much already. Just in bed, and during meals. And some leg day exercise to boost my thigh energy.
Mai scare me leg. My scan results are out. Ligament tendon all good. Just bone broken and one part dislocated. Broken part all screws. Dislocated, screwed back to strengthen.