We often tend to throw yoga concepts left and right without fully understanding what they mean.
Calling someone flexible is automatically perceived as praise and approval. Whereas lacking flexibility is the curse and one of the chief complaints beginners have when they find themselves not being able to do many yoga poses.
But what if I told you that flexibility is often the last thing you should worry about? And lots of times your hamstrings are not to blame for the fact that you can't touch your toes?
If you think that mobility is equivalent to flexibility and stability is the same as balance, I invite you to explore these ambiguous, yet so different, concepts with me.
Read on about the difference between flexibility, mobility, and stability, how they associate with each other, and why you should bother about the terminology when getting on your yoga mat.
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Every joint in our body has its range of motion (ROM). A range of motion in simple terms means how well and far a joint can move within its joint capsule without causing you pain, discomfort, or any other issues.
Flexibility is the ability of muscles and connective tissues (ligaments, tendons) to temporary elongate so a joint could move through a range of motion (ROM).
When we show off our flexibility, it often involves the help of some external force: a person, a tool, a wall, etc. So the range of motion we can achieve with the help of external force is always passive.
Think of flexibility as a passive static action. The degree of your flexibility determines how ‘deep’ you can get in your yoga poses and stretches without involving any other body resources such as strength, coordination, and the like.
Let's use Tree Pose Vriksasana as a visual example here.
If you bend over and grab your foot to place it on your thigh, that's your degree of flexibility in the pose or a passive range of motion. You used the external force, in this case, the strength of your hands, to lift the foot and put it as high as you could.
Good old static stretching exercises are the first thing that comes into mind when we want to improve flexibility. They can be effective, according to science.
But there's one problem. Well, several problems, if to be more accurate.
First, the increased ROM or flexibility gained by stretching is hard to sustain. If you haven't noticed before I've mentioned the phrase 'temporary elongate.' Often, your increased range of motion will go back to the usual as soon as you stop your stretching routine.
Second, nobody really knows how much, how long, and how often you need to stretch to become more flexible. That might even depend on your genetics. Oh, and there's no one proper stretch that will get you to your flexibility goals fast.
Third, there is no real science-backed evidence that says that stretching and passive flexibility are good for us. You can check more on why we stretch and the benefits of stretching in the post about my 30-Day Splits Challenge.
Mobility is the ability of your joint to move through a range of motion actively while maintaining control over the movement. Mobility is also sometimes referred to as active flexibility or active range of motion.
Here's how that works in practice.
Try to get in the same Tree Pose. But instead of grabbing your foot with your hands, see how high you can place it without the aid of hands. That means you have to lift the foot using your muscles, rotate it externally and put it on your thigh.
The thing is that you'll always have a greater passive range of motion than the active range of motion.
Because of the brain!
I won't get into the nitty-gritty of how our nervous system is controlling our movement. What is essential to understand here is that our brain is in charge of everything that's happening in our bodies. It is responsible for keeping us alive and safe.
So whenever we're trying to execute an active movement that might be harmful to our joints or body in general, it imposes a neurological barrier that limits us from going where it thinks we're not prepared to go yet.
Every time you're actively lifting your foot off the floor to get into Tree Pose, your brain asks itself: "Is the joint safe? Do they have sufficient motor control (aka stability) and strength to move further in the pose?"
If your foot goes only as high as the knee even though you can passively get your foot all the way up to the hip crease, it probably means the answer is "No." Your brain is trying to protect the body from pain and damage because you're actually not ready to accomplish the movement in full.
There is a strong association between flexibility and mobility. While flexibility determines how far you can move, your mobility shows how much control you have over your movement and how safe this movement is for you.
This grey area between how deep you can get into a yoga pose with external help (flexibility) and how deep you can go using only your body (mobility) is exactly where lots of dirty yoga injuries happen. Because though you can get your body move that way, you don't really have any control over that movement.
Another clear example of the difference between flexibility and mobility is the Full Splits pose, aka Hanumanasa.
Say you ask a highly flexible person to get into full splits. They will be able to do this because they have good passive ROM. Though, probably they won't be able to activate their muscles and get up without using their hands because they don't have adequate control over this posture. A person with high mobility at the same time will be able to use the strength in their legs and core to get into and out of the full splits.
So apart from flexibility, mobility also involves strength and stability that help protect your joints and allow you to have active control over your movement.
Mobility = Flexibility + Strength + Stability
Stability is the ability of your body to prevent unwanted movement under the influence of external forces and maintain control over your joints. If that sounds all too confusing and similar to balance, let me clarify it for you.
If you can stand still in Tree Pose with your hand in the prayer position for 5 minutes, you probably have good balance. But this doesn't necessarily mean you're stable.
Now imagine you're standing in Tree Pose. You're so perfectly still that your classmate next to you gets jealous and throws a yoga block at you (let's just hope the block isn't wooden).
If you rock but return back to Tree Pose without falling, that means you're stable, and you have a great balance. Whereas in case your muscles in the standing leg were not engaged (passive Tree Pose), you'll probably lose the balance soon after the ball touches you.
Stability and mobility are interdependent. All our joints have a certain degree of both stability and mobility. Some favor one over the other for efficient and healthy movement. For example, hip joints favor mobility over stability, while the lumbar spine needs stability.
Understanding the needs of each joint can help you choose (or create by yourself!) a functional at-home yoga program that will encourage a healthy balance between mobility and stability for safer and better movement on and off the yoga mat.
Check out more about 'joint-by-joint approach' if you're interested.
The answer is, of course, all of them. All three concepts are interconnected.
There's no strength without stability and no stability without strength. There's no mobility without a healthy range of motion and joint stability. But there's a whole dangerous world of passive flexibility without control.
You can't just train one thing without the other. Well, the truth is that you can, but it’s not efficient and might be potentially dangerous.
The concepts of flexibility, mobility, and stability are essential for movement. You need muscle strength to support the movement and elasticity to be free to move.
Understanding the difference between stability, flexibility, and mobility can drastically change how we view our yoga practice, how we approach it, and how we structure yoga classes.
While being flexible may look dandy, it actually does nothing in terms of performance, better movement, or injury prevention.
In fact, increased passive flexibility around which many yoga classes are built can be downright dangerous and lead to an excessive range of motion in the joints (also called as joint instability or joint hypermobility) and potential injuries.
It is actually mobility and training an active range of motion that we should focus on most of the time on the yoga mat. Mobility stretches and drills can not only increase the joint range of motion but also reduce the risk of injury, correct muscle imbalances, decrease muscle tightness, and joint pain.
Takeaway message: Passive flexibility without strength and control is dangerous and useless. Finding a balance between strength, stability, and flexibility is the key to making all our movements safer, better, more efficient, and pain-free.