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.
U.S. National Library of Medicine(0.00 / 0 votes)Rate this definition: Goiter, Substernal. An enlarged THYROID GLAND with at least 50% of the gland situated behind the STERNUM. It is an unusual presentation of an intrathoracic goiter. Substernal goiters frequently cause compression on the TRACHEA leading to deviation, narrowing, and respiratory symptoms.