0 Question: your sternocleidomastoid is the muscle on your neck. what does it do? Keywords: muscle, neck, sternocleidomastoid Asked by gejl to Helen, Mark, Martin, Stu on 22 Jun 2011.
Helen O'Connor answered on 22 Jun 2011:
It helps us pull the head forward and down, and also stops the head from falling backwards. http://www.round-earth.com/SCM.html
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