It works better if you add a couple more joints, (as in segments) to the elbow & knee areas . Then apply curves to each segment. Usually I see the curve feature added to tails on an animal, but I don't see why it won't work on those cute little arms legs too. I reco setting the min & max rotation for all the segments to keep a tight leash on their wanderings. Usually 20 degrees in the bend, zero in the front to back.