Hey Vally! Welcome to Bluelight. I love easy questions. This is indeed not a normal or expected reaction associated with Oxycodone (Percocet; Oxycontin) or other Opioids for that matter. This would be filed under "abnormal reaction" but that doesn't mean it's an abnormal reaction for you, it just means that your physiology for one reason or another causes what I assume would be called Myoclonic Tics At any rate, I wouldn't keep using it if you're experiencing strange or unexplained neurological symptoms.
All good?