In addition, since isometric exercises are done in a static position, they won't help improve speed or athletic performance. They can be useful, however, in enhancing stabilization â maintaining the position of the affected area â since muscles often contract isometrically to aid in stabilization.
Etiology. Most (85-95%) substernal thyroid masses represent benign goiter. Historically, goiters have generally occurred because of iodine deficiency, although this is now observed primarily in developing nations.
Thyroid nodules vary greatly in size. Many are large enough to see and feel (palpable nodules). Some multinodular goiters can become enormous, bulging out of the neck and over the collar bones or extending down into the chest behind the breastbone, a condition called substernal goiter.