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.
Another type, called toxic nodular goiter, results when one or more nodules, or adenomas, develop in the thyroid and trigger excess production of thyroid hormone. In short, a goiter is any enlargement of the thyroid gland. A goiter may be a temporary problem that will remedy itself over time without medical intervention, or a symptom of another, possibly severe, thyroid condition that requires medical attention.