noun
involuntary movement
Medical term for movements that occur without conscious control, such as tics, tremors, or spasms.
パーキンソン病では、不随意運動が見られることがある。
In Parkinson's disease, involuntary movements can sometimes be observed.
随意運動 means voluntary movement, the opposite of 不随意運動.
Compound of 不 (fu, 'not') + 随意 (zuii, 'voluntary') + 運動 (undō, 'movement'). A straightforward medical term.