You can also try to place your baby on his or her back, and then move his or her legs in cycling motions. (followmum.com)
Cycling legs — When changing your baby's nappy or any other time you have a moment when they are lying on their backs, gently take their feet and make cycling motions with their legs. (toddler-activities-at-home.com)
We're not sure why, but most babies love having their little legs moved in a cycling motion. (babycenter.com)