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 :
The Lord of the Rings film trilogy. In the Lord of the Rings film triloft, Pippin is played by Billy Boyd, who is the oldest of the actors portraying the four protagonist Hobbits (Elijah Wood, who plays Frodo, is the youngest).Pippin's foolish acts are mainly for comedic relief.he Lord of the Rings film trilogy. In the Lord of the Rings film triloft, Pippin is played by Billy Boyd, who is the oldest of the actors portraying the four protagonist Hobbits (Elijah Wood, who plays Frodo, is the youngest).