July 01, 2021

What's the difference between a ligament and a tendon?

Q: I thought I was experiencing a bout of tendinitis in my wrist, but my doctor said I actually have a torn ligament. What's the difference between a ligament and a tendon?

Ligament and tendon

A tendon begins at the end of each muscle, connecting the muscle to a bone. Its primary purpose is to assist in joint movement. In contrast, a ligament connects one end of a bone to another with no muscle involved in the connection. Ligaments provide joint stability and guide joint motion.

 

A: Ligaments and tendons work in conjunction with muscles, joints and cartilage to support, stabilize and power body movements. When you shrug your shoulders, point your toes or sit up straight, your body's tendons and ligaments are at work.

There are some similarities in the makeup of ligaments and tendons. They are both formed from dense, fibrous connective tissue. The tissue contains collagen and elastin fibers, giving them strength and flexibility. But they have important differences in their placement and function.

A tendon begins at the end of each muscle, connecting the muscle to a bone. Its primary purpose is to assist in joint movement. As the body's natural shock absorbers, tendons are cordlike and can be stretched up to 15% of their original length without being damaged.

The Achilles tendon is the longest tendon in your body. It connects your calf muscles (gastrocnemius and soleus) to your heel. This connection allows for a variety of motions, including pointing your toes and pushing off when running or walking — all while helping to hold the heel in place.

In contrast, a ligament connects one...