No mention of how a persons lifestyle changes over that period though. Surely there is a correlation to the causation? The head-bone is connected to the neck-bone etc... You cannot study figures in isolation and expect them to yield some meaningful results while ignoring the influence of other figures upon those results. - Kids move around a lot, and they're still growing/developing - Teenagers move more constructive…
https://cdn.vox-cdn.com/thumbor/U1RxtW9oglcck-2g2X_SrKzIA44=...