Flexibility, Mobility, Stability, & Strength
Clarifying Mobility & Flexibility
Mobility and flexibility are terms that are often used interchangeably when in actuality they are two different things. Flexibility is how much range of motion is available at a joint while it is being passively moved. For example, a hamstring stretch where you position the leg being stretched up against a door frame while you're laying down. You are laying down and letting the door frame passively stretch your hamstring, making this very much a passive modality.
To contrast that, Mobility is how much range of motion you actively control at a joint. To keep on the topic of hamstring and hip range of motion, an example of testing mobility in your hamstring and at your hip joint would be doing an active straight leg raise while laying down. You are actively trying to flex your hip against gravity and seeing how much range of motion you have control over in this manner. Another, more advanced example of this would be a Single Legged Romanian Deadlift. Why does this matter? Flexibility is a measure that can be a good indication of what may be happening at a joint, but for some, is not the appropriate goal or focus. Generally, we might want to focus on how much range of motion we have access to through movement, which would be our mobility metric. If you can do a toe touch while sitting perfectly fine, but then you try and do a loaded RDL and aren't able to without form errors and losing balance, then maybe our focus should flip from doing passive stretches to improve flexibility, and transition into exercises, stretches, and positions that will help us improve your mobility. Control is the name of the game. Improving mobility in a joint can be a very important part of you managing a nagging injury, improving performance in your sport, making you feel more confident in your daily tasks, etc. From mobility, we want to move into the realm of stability. Stability gives us control over our positions so that we can eventually go and load. So what is stability? We define stability as the ability to resist force. (Pre-Script) Think of it this way. If we are looking to do a task, let's say pick a box up from the floor, we need to coordinate musculature contractions concentrically and eccentrically to be able to do so. With this, force is produced moving our body through space. But in order for there to be the most efficient production of force, there needs to be a stable structure for us to act against. Something that would be able to resist the force we are producing.
Without stability, there is a higher likelihood of leakage of force through the kinetic chain somewhere. The body is really efficient at finding the path of least resistance and making up for that stability somewhere else- often somewhere that shouldn't be taking on that load. This could potentially lead to an injury, lack of confidence doing specific tasks throughout your day because you feel "unstable", or decreased performance in a sport.
How do you test stability? Evaluate your movement and notice where there may be inefficiencies and use specific tests/movements that will give insight into your ability to be stable in unstable positions. Finding ways for you to challenge stability internally is key. Deviate your Center of Mass (COM) or lessen your Base of Support (BOS). By doing this your body needs to internally stabilize to prevent you from falling over. For example, you can deviate your COM by holding a Kettle Bell in one hand, and then further challenge stability by standing on one leg, lessening your BOS. You can do the same with the upper body by holding a KB overhead.
Stability should be challenged as often as can be tolerated. The more capacity you have to stabilize at a joint, the more that that joint will be able to tolerate load and produce force, which takes us to the next level of progression strength. Strength As we mobilize into new positions and have the ability to create stability in these positions, we can then begin to add load and get strong. Strength can be defined as the ability to produce force and is often where the rubber meets the road.
This is where progressions can go far and beyond what you thought you were capable of. Oftentimes it is a familiar metric that we associate with while being in the gym; graduating from using 40lb dumbbells for chest press up to 50lb, having more weight on the bar for squats, etc.
The way to test strength is pretty straightforward. See how much you can lift a weight at a certain amount of reps until failure or close to it to test how strong you are at something. The lower the reps that you test how much weight you can lift for, the more accurate you will be in determining your maximal strength at that movement. So then how do we get stronger? To put it as simply as possible, you have to lift more weight over time and at a lower rep range. For general strength purposes, it is recommended to stay within the 3-6 rep range for compound movements in your training, of which over time you go to the lower end of that range, allowing you to get more specific to the task of strength by loading more weight for fewer reps. In week 1 of your training you can bench press 100lbs for 5 reps, then the next week you can go up to 105 lbs. (Of course this weight increase depends on individual capacity and factors). By increasing the working weight over time, within reason, your nervous system will adapt and make you more proficient at being able to recruit musculature to exert force. There will also be muscular changes, such as an increase in size, but this may take a bit longer. Remember to get stronger, you need to lift more than you previously have.
When you get more advanced, strategies will change and you will need to have a bit more thought put into your programming, but to start, just try and do more than you have in the past.
We hope that the importance of gaining the mobility to move into positions, then gaining the ability to stabilize in these newly acquired positions so that we can load them and become stronger has been shown over the past few weeks. All of these are important in becoming pain-free, better at your sport, and more comfortable moving through life. Once you can identify which spot you need to work on it becomes easier to create a plan of action to recover and become better.