Assertion: jerk | /r/CreatedBy | sudden muscle contractions
Facets:
value: usually
type: TEMPORAL
value: by muscle relaxation
type: CAUSE
Source sentences:
text: Myoclonic twitches or jerks usually are caused by sudden muscle contractions, called positive myoclonus, or by muscle relaxation, called negative myoclonus.
text: These myoclonic twitches, jerks, or seizures are usually caused by sudden muscle contractions (positive myoclonus) or brief lapses of contraction (negative myoclonus).