痙攣 こむら返り
Sometimes known as a Charley horse or corkie, a cramp is associated with strenuous activity or for keeping an uncomfortable position for too long and it can be intensely painful—though skeletal cramps can occur while relaxing. 

For use with images:
Any image depicting a character looking at or grasping their thighs, calves, or a foot while in pain.

h4. See also

* [[stomach ache]]
cramp