Flexibility and mobility are pretty much the same things, right? It might seem that way with a superficial glance. But really they’re different enough to warrant a discussion.
Flexibility And Mobility
So if flexibility and mobility are different, how are they different? It’s a very small difference but it’s a very important difference. For a very long time, mobility and flexibility were basically defined as the same thing. It’s only recently that they have really started to separate in the mainstream.
It’s actually a good thing they did because now we have better language to discuss movement. So let’s define these two words and look at what that means for you. And so we’re clear, these are my definitions as they relate to human movement.
Flexibility – the range of motion your joints have without active muscle engagement
Mobility – the range of motion you can move your joints through with active muscle engagement
Can you spot the difference? What does it mean to you? Here’s the way I see it.
Flexibility is the range of motion you have when you place yourself in a position and allow your muscles to relax, this will often further increase the range of motion.
However, you are unlikely to accomplish much, if any, work in this range of motion. In other words, you have very little control over your body in this range of motion.
You see this often with people pulling on their bodies to get into a particular position or to “increase the stretch”. So you are not using the muscles that control that joint to get into that position. You are using tools to assist the range of motion.
Mobility, on the other hand, is the range of motion you can move your joint through while using the muscles the control that joint. This is the difference between sliding into the splits and picking your legs up into the splits while hanging from a bar.
In the first example, you’re using your body weight and the ground to help get into the position. In the second example, you have to physically move your body into position under its own power.
Mobility should be the goal. If you have a lot of flexibility with little mobility you’ve set yourself up for injury and poor joint health. Muscles are what really hold the joint together. Ligaments are just there for emergencies and basic stability. They shouldn’t be keeping your knee or shoulder from coming apart.
Too much flexibility without enough strength in the muscles around the joint (i.e. mobility) places extra stress on the ligaments, which don’t do a good job with this added stress, and then long-term extra joint wear is the result. This culminates with a joint replacement or ligament tears at the extremes.
Flexibility work is a great way to open the door for more mobility work. But don’t forget that once you open up those joints you need to teach those joints to support themselves!