Data have been presented relative to the strength and force-elongation relationships of rat ligaments. The findings indicated that the testing methods employed are sufficiently reliable for experimental purposes. Results showed that body weight, sex, and age of the animals are important parameters when evaluating separation force results. Absence of adrenal or thyroid glands had no significant influence on the strength of the medial collateral ligament. It was concluded that the strength of the medial collateral ligament was dependent upon its osseous attachment.
Force-elongation data suggested that ligamentous strength and elongation are independent properties. Ligaments from adrenalectomized and thyroidectomized rats exhibited significantly more elongation than ligaments from normal rats. The responsible mechanisms are unknown and are the focus for current studies.