Why babies need to move in the womb [sciencedaily.com]
Scientists have just discovered why babies need to move in the womb to develop strong bones and joints. It turns out there are some key molecular interactions that are stimulated by movement and which guide the cells and tissues of the embryo to build a functionally robust yet malleable skeleton. If an embryo doesn't move, a vital signal may be lost or an inappropriate one delivered in error, which can lead to the development of brittle bones or abnormal joints.
[...] "Our new findings show that in the absence of embryonic movement the cells that should form articular cartilage receive incorrect molecular signals, where one type of signal is lost while another inappropriate signal is activated in its place. In short, the cells receive the signal that says 'make bone' when they should receive the signal that says 'make cartilage'."
Prior to this discovery, using chick and mouse embryos where movement could be altered, the scientists had previously shown that when movement is reduced the articular cells at the joint do not form properly, and that in extreme cases the bones can fuse at the joint, but they didn't know why. Now, they have isolated the mechanism underlying healthy development, which has provided new insights into what type of embryo movement is important and the specific signals that are needed to make a healthy joint.
This could have implications for physiotherapy as well as artificial wombs [soylentnews.org].
Precise spatial restriction of BMP signaling in developing joints is perturbed upon loss of embryo movement [biologists.org] (DOI: 10.1242/dev.153460) (DX [doi.org])