Some fans on Reddit noticed similar hand tremors during Hamill’s appearance at Star Wars Celebration in Orlando last year.
Hand tremors can be caused by something innocuous, but can also be an early symptom of serious neurological illnesses.
DailyMail.com has reached out to Hamill’s representatives for comment.
The star reprises his role as Luke Skywalker in Star Wars: The Last Jedi, out December 15. Also in the movie is the late Carrie Fisher.
(Source: Daily Mail UK)