“I jammed my finger. Did I hurt my tendon or my ligament?” We often get inquiries similar to this question. People are often confused about the difference between a tendon and ligament. So, let’s take a quick look at the purpose of each structure.
According to Merriam-Webster, a tendon is “a tough cord or band of dense white fibrous connective tissue that unites a muscle with some other part (such as a bone) and transmits the force which the muscle exerts.” To put it simply, a tendon involves movement or range of motion. Muscles are made to contract. The tendon connects a muscle to bone. So, when the muscle contracts or shortens, it pulls the tendon which is attached to a bone resulting in motion. For example, your biceps muscle originates at your shoulder. The biceps tendon inserts into the forearm. When the muscle contracts, the resulting action is elbow flexion.
Now, let’s explore ligaments for a moment. According to Merriam-Webster, a ligament is “a tough fibrous band of tissue connecting the articular extremities of bones or supporting an organ in place.” The old adage is a ligament connects bone to bone. Whereas tendons are all about motion, ligaments are all about stability. Ligaments are supportive structures that help your joints remain stable. If a ligament is torn or ruptured, then the joint becomes extremely unstable and usually results in surgical intervention. A common ligament injury that most have heard of is an ACL tear in the knee. When the ACL is torn, the knee becomes unstable and normally requires surgery. So, remember that tendon connects muscle to bone and ligaments connect bone to bone. Tendons are all about motion and ligaments are all about stability.
We could go into much more detail and speak about numerous tendon or ligament injuries that affect the hand and upper extremity. However, because there are so many different tendons and ligaments, your anatomy 101 lesson for today is complete. Don’t you feel smarter already?