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.
Deep Neck Flexor Exercises. The deep neck flexors can be activated by a simple nodding movement of the head on the neck called a chin-tuck. The tucking the chin activates the deep flexor muscles and moves the chin closer to the âAdamâs appleâ (Thyroid cartilage).eep Neck Flexor Exercises. The deep neck flexors can be activated by a simple nodding movement of the head on the neck called a chin-tuck. The tucking the chin activates the deep flexor muscles and moves the chin closer to the âAdamâs appleâ (Thyroid cartilage).