Twitch, e.g. (5)
I believe the answer is:
spasm
(Other definitions for spasm that I've seen before include "Sudden convulsion" , "Sudden involuntary contraction of a muscle" , "Painful muscle contraction" , "Muscle twitch" , "sudden movement" .)
I believe the answer is:
spasm
(Other definitions for spasm that I've seen before include "Sudden convulsion" , "Sudden involuntary contraction of a muscle" , "Painful muscle contraction" , "Muscle twitch" , "sudden movement" .)