Let me ask you a question: are you mobile or are you flexible? I’m sure this is not a question you get asked a lot and you may be asking yourself, “what is the difference?” Well, I’m glad you asked because we are constantly explaining this to our patients in physical therapy.
Think of these two terms in the following way: flexibility is like the gas tank in your car and mobility is the gas that fills that tank.
The larger your gas tank, the more gas you can put into it, however an empty gas tank isn’t very useful!
Flexibility is a measure of how pliable your tissues are. In other words, flexibility measures how much motion a given area of your body has passively.
Imagine, for a second, that you are lying on your back and someone begins lifting your leg to stretch your hamstring. This demonstration is a measure of how much flexibility you have. Take into consideration that you are not actively performing this motion.
Mobility is a measure of how much motion a given area of your body possesses which you can use actively. Imagine, once again, that you are lying on your back as described above. But this time, you are keeping your leg straight, actively lifting it up on your own. The distance you are able to lift your leg is a measure of your mobility because you executing this activity independently.
Great mobility requires the ability to generate strength throughout the large amount of flexibility made available in our bodies. This is one way that athletes can become more resilient to injury.
Injury risk increases as the gap between flexibility and mobility widens. In this situation, an individual has a large range of motion which he or she cannot use effectively. Therefore, when this person goes into their end ranges of motion, injury risk increases because he/she is unable to generate the necessary amount of strength for the activity (ie. They have the flexibility to get there, but not the mobility to use it).
One easy way to protect against this is to contract the muscles involved in a stretch when in the stretched position. This method of stretching reinforces the use of these muscles when they are close to the end of their range of motion.
In the below videos, my colleague, Dr. Alex Immermann does a great job demonstrating these drills.
Seated 90/90 External Rotation PAILs
Wall Ankle Stretch PAILs/RAILs
Take a look and let us know what you think!