Have you never seen a person having a convulsion? I'm not expert, so I'm not sure - I'm only posting this to point that there may be a medical explanation.
Extract.
Symptoms[edit]
When a person is having a convulsion, they may experience several different symptoms. These may include: a brief blackout, confusion, drooling, loss of bowel/bladder control, sudden shaking of entire body, uncontrollablemuscle spasms, temporary cessation of breathing, and many more. Symptoms usually last from a few seconds to around 15 minutes. If someone has a fit like this, it is advised to make sure they don't fall and injure themselves, cushion their head and loosen any restricting clothing/jewelry, and also call for medical help. Do not try to pin/hold them in place, as this could possibly cause harm or injury to the individual.[1]
