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.
Toxic multinodular goiter: A condition in which the thyroid gland contains multiple lumps (nodules) that are overactive and that produce excess thyroid hormones.Also known as Parry disease and Plummer disease.oxic multinodular goiter: A condition in which the thyroid gland contains multiple lumps (nodules) that are overactive and that produce excess thyroid hormones.