If we focus on the locomotor apparatus, a ligament is a fibrous cord that connects one bone to another. Most of the time, it is a simple thickening of the articular capsule, of which the ligament is therefore part.
It is composed of connective tissue, the fibers of which, essentially made of collagen, all have the same direction.
The ligaments have at the same time a role of mechanical restraint and act as a support of sensitive information.
Indeed, it contributes to the stability of the joint by resisting traction thanks to collagen fibers. But if it is exposed to too much tension or traction, the ligament may then distend or tear, it is a sprain.
The ligament is also very rich in sensory nerve receptors of proprioception. Sensitive to pressure, tension, acceleration, it allows the brain to know where this part of the body is in space.
In the event of a sprain, the nervous system will be damaged at this location, which explains why sprains often repeatedly occur in the same place, since sensory information perceived and emitted by the area has become less reliable.
Conclusion: never try to stretch a ligament!
On the other hand, our body hygiene, our daily posture can cause some ligaments to remain “wrinkled”, as Blandine Calais-Germain put it, in a chronic way, it is then useful to work to restore their initial length.