【A body whose spine works】 When the spine links up more, you can enjoy more kinds of things The occipital bone and the first cervical vertebra form a joint = atlanto-occipital joint It takes part in nodding "mm-hmm" motions When the head sits loosely atop the top of the spine, the spine stays loose When it sits engaged, meshing, the spine links up too

A video posted by @33inchi on X (formerly Twitter) (August 16, 2023 ・ その他 ・ 1:52). Watch and download it on XCLYP.