Â© 2000 John Wiley & Sons, Inc. An inverse relationship between household income and violence exposure in youth hasbeen reported in numerous studies (e.g., Garbarino & Crouter, 1978; Gelles, 1992; Gelles& Straus, 1979; Steinberg, Catalano, & Dooley, 1981).
The head, attached to the top of the vertebral column, is balanced, moved, and rotated by the neck muscles (). When these muscles act unilaterally, the head rotates. When they contract bilaterally, the head flexes or extends. The major muscle that laterally flexes and rotates the head is the sternocleidomastoid.
MUSCLE OVERVIEW The Sternocleidomastoid (or SCM) is a muscle in the neck region that runs obliquely along the side of the neck in an inferomedial and anterior direction. This muscle flexes and rotates the head. It also acts as an accessory muscle for inspiration. The muscle has two heads: (1) The sternal head and (2) [â¦]