In 1980 Alberca et al. described a patient with a syndrome of increased muscle irritability, who presented ondulating muscle rolling movements and electrically silent cramps, myoedema and muscle reactions to mechanical stimulation similar to myotonic response, suggesting a disfunction at myofibrillar level.
For c-3po, it was a costume, Anthony Daniels played c-3po: For R2-D2, It was a costume and a remote controlled robot. CGI was also used in the prequel trilogy. So, they had Kenny Baker to play him : And from Portrayal section of wookieepedia article on R2-D2 :
Pat Harrington Jr. as Schneider on 'One Day at a Time.' He won an Emmy and a Golden Globe for playing the colorful Dwayne Schneider on the long-running CBS comedy. Pat Harrington Jr., who played the cocky superintendent Dwayne Schneider on the CBS sitcom One Day at a Time, has died. He was 86. Harrington, who won a Golden Globe in 1981 and an Emmy Award in 1984 for his work on the show, died Wednesday night in Los Angeles surrounded by his family, his children Tresa and Terry reported on Facebook.