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.
Trapezius Muscle. The trapezius is one of the major muscles of the back and is responsible for moving, rotating, and stabilizing the scapula (shoulder blade) and extending the head at the neck.It is a wide, flat, superficial muscle that covers most of the upper back and the posterior of the neck.Like most other muscles, there are two trapezius muscles â a left and a right trapezius â that are symmetrical and meet at the vertebral column.The trapezius arises from ligaments at its origins along the nuchal crest of the occipital bone and the spinous processes of the cervical and thoracic vertebrae....ike most other muscles, there are two trapezius muscles â a left and a right trapezius â that are symmetrical and meet at the vertebral column. The trapezius arises from ligaments at its origins along the nuchal crest of the occipital bone and the spinous processes of the cervical and thoracic vertebrae....