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.
To Correct Forward Head Posture, the muscles which need to be stretched comprise of: 1  Upper cervical (capital) extensors: Semispinalis capitis, splenius capitis, longissimus capitis and suboccipital muscles. 2  Lower cervical flexors. Sternocleidomastoid muscle, medial and anterior scalene muscles.
Function. A unilateral contraction of the sternocleidomastoid muscle flexes the cervical vertebral column to the same side (lateral flexion) and rotates the head to the opposite side. A bilateral innervation leads to an elevation of the head (dorsal extension).unction. A unilateral contraction of the sternocleidomastoid muscle flexes the cervical vertebral column to the same side (lateral flexion) and rotates the head to the opposite side. A bilateral innervation leads to an elevation of the head (dorsal extension).