The Difference Between Flexibility and Mobility: How to get more movement in a tight joint.
When someone notices stiffness in their body they tend to think about increasing their flexibility, not realizing that the concept has evolved and with it the language we use to describe our capacity to move with grace and control at the limits of our joints’ range.
Feeling stiff and uncomfortable as we try to get ourselves to do various motions that come up in our life or sport is not pleasant, and indeed it is a marker of a lower state of physical fitness.
But is stretching the answer?
Before I move on with what I have to say, I want to acknowledge that there is more than one type of stretching. I’m only speaking of the one that I know comes to mind for most people when I say…
Stretching is not the best path toward reducing our stiffness and limited joint range.
Stretching, as done by most people, is the process of putting a joint into positions at the end of its range and waiting a little while for the sensation to change. But any additional motion that’s gained is only available when forces outside of the joint are used to create the position.
For instance, if I grab my foot and pull my leg out in front of me and up as far as it will go. I’m stretching my hip joint, but it’s the effort of my arms that was used to create the motion.
This is flexibility. In flexibility the involved joint is passive, it’s not working to create the position.
Mobility is flexibility plus strength and control. Actually it’s flexibility plus control, and the tool to get there is strength.
You know that its mobility when the muscles around the involved joint are being used to create the motion.
For instance, if I lift my leg out in front of me without using my hands, then it’s the muscles around my hip joint that have to create the motion.
It will always be the case that my range of mobility (active movement) will be less than my range of flexibility (passive movement).
If our body can be placed in a position, but can’t control that position, injury can occur. The body knows this, so it continues to limit the available range of movement until control is present.
So, in mobility training a person will be working on increasing the ability to actively move their joint, while maintaining internal, local control of the motion.
I hope it’s clear now how this is different than stretching, where a person will be working on increasing how far a joint will move, but not thinking about whether they can control that motion internally and with the muscles that are nearest to the involved joint.
In order to control motion we need strength.
In this video on hip mobility the authors have created a progression from passive flexibility to active mobility. If you watch it you’ll notice that the presenter at one point says, “No weight is needed with this. You’re just doing body weight, end range activation.”
What he means is that, as with most exercises, after mastering an easier version of the exercise we need to change to harder and harder versions so that we can continue to gain strength, skill etc. But for this mobility exercise it’s not necessary to make it more difficult through the use of external weight, just using the weight of the leg creates enough work for the muscles around the joint.
If we were talking about mobility for the shoulders we would want to quickly progress to using more weight than just that of the arms. Some exercises are set up so that the weight comes from the shoulders moving the rest of the body, and some exercises are set up by adding weight to the arms by holding onto dumbbells. It can be too much of a leap to go from just using the weight of the arms to trying to move the weight of the whole body because the body is so much heavier than the arms.
Whether you progress (make more challenging) the exercise by adding weight, or whether you just do the exercise by actively engaging the muscles around a joint to create movement, you are doing a mobility exercise and there is great benefit to those movements.
You’ll also notice he points out that the model is holding onto something because “this is a mobility exercise, not a balance exercise.” Mobility and balance are both important markers of fitness, but it’s helpful to know which one you’re working with so you can put your focus on that element.
When you make an active movement you are choosing to contract and relax a muscle (or several related muscles). This helps it show up on your mental map of your body. Which in turn gains you a more detailed awareness of the area and allows you to regain your ability to engage it consciously. All skeletal muscles are under our control, but sometimes we lose the ability to choose by losing track of our body.
By choosing to move your joints with control you change your nervous system and regain control of your body.
Also, a lot of the time what limits movement is not the shape of our joints or some underlying pathology, but the body’s nervous system itself. It has the option to stop us until we take the time to slowly practice the motion and show it that we can do it safely.
By practicing motions actively we can demonstrate to our own nervous system that we have a coordinated control of our body. By practicing them slowly we allow ourselves to explore the unknown and thereby to extend our safe range–in the same way that we would slow down if we were blindfolded. Once the range is known to be safe we can speed the motion up to the rate that we would do it in our daily activities.
The benefit of slowing down the motion is the same as the benefit of moving around slowly with a blindfold on–more of the nuances of sensation can be detected, and they can also be responded to with more nuance, rather than triggering a sudden, reflexive response.
I should point out that everything I’ve said applies to the spine as well as the arms and legs.
