Bone & Joint Health, Joint Knowledge
Joint Knowledge: Tendons vs Ligaments
Jul
Do you get confused by the terms tendon and ligament? If so, you are definitely not alone.
These two types of connective tissue tend to be used interchangeably by many because they are, in fact, similar. Yet, they do have different and essential functions.
Tendons vs Ligaments
First and foremost, both tendons and ligaments fall under the category of connective tissue along with:
- Cartilage
- Bone
- Adipose (fat)
- Blood
Yep, blood is a type of connective tissue!
Connective tissue gets its name from what it does in the human body — it creates connections.
The functions of connective tissue include:
- The transport of nutrients
- Protection
- Mechanical support
Tendons and ligaments fit into the last group: mechanical support.
If you’ve ever strained a tendon or sprained a ligament, you are familiar with the major similarity between these two connective tissues: they allow us to move. (And when injured, our movement is limited and often painful!)
Putting together what we’ve learned so far: tendons and ligaments are connective tissues that allow us to move.
So, what are tendons?
Tendons are very tough bands of connective tissue that attach muscle to bone.
Let’s take a look at one of the most well-known tendons of the body: the Achilles tendon. This strong tendon connects your calf muscle to your heel bone. When healthy, your Achilles tendon allows your foot to move at your ankle joint.
To be clear, it’s not the tendons that do the work–it’s your muscles that work!
Your tendons are what anchors the muscle to the bone.
Going back to our Achilles example, your calves generate the strength and power to move, and your Achilles’ tendons act as anchors to the heel in your foot can move. Without your Achilles tendon, walking would be nearly impossible, and your foot would merely flap back and forth!
You have tendons in places you wouldn’t expect, too. They help move your eyes, eyelids, and jaw. Your head is attached to your neck with the help of tendons, and they play a critical role in its movement.
Here are some examples of what tendons allow you to do:
- Twist in a chair
- Give two thumbs up
- Wiggles your toes
- Kick a soccer ball
What Are Ligaments?
Ligaments connect bone to bone (unlike tendons, which attach muscle to bone).
You can argue that a joint is a joint because of its ligaments involved. After all, if your upper leg and lower leg aren’t connected…your knee joint isn’t…well, jointed.
The knee joint is a great example to look at when it comes to studying ligaments. There are four ligaments that work together to keep your knee joint sturdy and secure by keeping the upper and lower leg bones (i.e., the femur to the tibia) connected:
- Anterior Cruciate Ligament (ACL)
- Posterior Cruciate Ligament (PCL)
- Medial Collateral Ligament (MCL)
- Lateral Collateral Ligament (LCL)
If one of these ligaments is torn or injured, walking is possible…it’s just considerably less stable (and most likely, painful)!
As with tendons, you probably have ligaments in areas that you wouldn’t think about. For example, the periodontal ligament attaches teeth to the jawbone, and the suspensory ligament in your eye suspends the lens in place so it can reflect the light that allows you to see.
Tendons, ligaments, and your joint health
Now that you know the main structural differences of these two connective tissues, let’s get to the practical part of this article: how tendons and ligaments contribute to joint health.
Imagine your hip joint.
You have four ligaments connecting your upper leg bone (femur) to your hip bone (pelvis), very much like a ball in a socket. These ligaments help maintain the stability of your hip joint, preventing it from coming free or dislocating every time you take a step.
The tendons, on the other hand, connect the muscles of the leg, back and buttocks to the bones of the joint. If that sounds like a lot of muscle to you, you’re right! Besides walking, running, and jumping, your pelvis is the anchor for a lot of flexing and extending movements, like bring your knees to your chest, standing up from a seated position, or bending over to pick something up from the floor. In other words, tendons at the hip joint help aid movement.
4 key things to remember about tendons and ligaments
- Tendons connect muscle to bone
- Tendons play a big role in the movement of a joint
- Ligaments connect bone to bone
- Ligaments play a big role instability of a joint
It’s easy to confuse tendons and ligaments, but if you keep in mind these basic points…you’ll be on your way to making better joint health decisions!
