Plantar plate dysfunction is a common problem of the metatarsophalangeal joints that often just used to be called metatarsalgia. The problem is a strain or tear of the plantar plate that is a thickening of the plantar aspect of the joint capsule.

 

Resources:
https://podiatryarena.com/index.php?tags/plantar-plate/
http://www.podiatryexperts.net/uapage/22
https://thescienceandmyopinion.com/plantar-plate-tear-the-science-and-my-opinion/
https://plantarplatetear.com/