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.
Bilateral exercises work both sides of your body, as both limbs share the stress of the exercise. A barbell biceps curl is a bilateral exercise; a dumbbell biceps curl is a unilateral exercise. A bilateral exercise can be a multi-joint or single-joint movement. The barbell biceps curl previously mentioned is a single-joint bilateral exercise. The squat is a multi-joint bilateral exercise.