Kids naturally get a lot right...they dont know why they lye with thier legs up the wall and thier back on the floor...but guess what its a move that turns on your immune and drains the blood from any ruff and tumble inflammation...rendering them ready to go again tmw...until the elders told em to pack it and sit proper on a chair.
they also swing thier legs when sat on a picnic table or somesuch that allows thier legs to tick tock like a pendulum...adults wouldnt do that cause our culture would embarass em, truth is kids got it spot on, the swinging like the rickin chair juices...no dry crackin sounds when they stand up...nowt to do with age ( to a point) lifestyle dynamics.