All connective tissue structures have a rich nerve supply (see ‘bone bruise’ for details), particularly ligaments and tendons, which are the third most innervated structures in your body, behind the ‘mucous membranes’, like the surface of your eye, and your skin.  Ligaments and tendons have the third most sensory nerve fibers per volume of any structures in your body.  Nerve fibers have an interesting ‘structure’, which does not allow for any ‘stretching’.  Other than bone, nerve fibers are the least ‘stretchable’ structures in your body.  If you stretch a nerve fiber, you damage it.