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.
Neck muscles are bodies of tissue that produce motion in the neck when stimulated. The muscles of the neck run from the base of the skull to the upper back and work together to bend the head and assist in breathing.The motion of the muscles of the neck are divided into four categories: rotation, lateral flexion, flexion, and hyperextension.eck muscles are bodies of tissue that produce motion in the neck when stimulated. The muscles of the neck run from the base of the skull to the upper back and work together to bend the head and assist in breathing.