Question: what is the name of the main muscle that forms the calf
Answer: In humans , the gastrocnemius muscle ( / ˌɡæstrɒkˈniːmiəs / or / ˌɡæstrəkˈniːmiəs / ; plural gastrocnemii ; Latin , from Greek γαστήρ `` stomach '' and κνήμη ( knḗmē ) `` leg '' ; meaning `` stomach of leg '' ( referring to the bulging shape of the calf ) is a very powerful superficial bipennate muscle that is in the back part of the lower leg .