Tires â Retreading is less expensive than new tires and is a large portion of this cost. Although mere pennies per mile, an average tire can cost over $250 and annual tire expenses can exceed $4,000 ($0.03 per mile), enough to purchase 16 new tires annually, but still not enough to replace every tire of an 18-wheeler.
With the head in a forward position, a passive tensile force is created in the hyoid muscles resulting in hyoid muscle tension, causing the mandible to be depressed and translated posteriorly. The patient is therefore forced to contract the temporalis and masseter muscles to keep the mouth closed.
When a person bends forward, his paraspinal muscles are lengthening; when he stands up again, they are contracting to pull him back to a standing position. Paraspinal muscles on the left and right side of the body work together in the same way when the person bends sideways.When the person is not bending, the paraspinal muscles keep the spinal column in vertical alignment while he is sitting or standing.hen a person bends forward, his paraspinal muscles are lengthening; when he stands up again, they are contracting to pull him back to a standing position. Paraspinal muscles on the left and right side of the body work together in the same way when the person bends sideways.