To be honest, SMR is the name of doing massage on your own, releasing tension and relaxing the trigger points. You can do it with your own hands, foam rollers, balls (tennis balls or specially designed lacrosse balls).
To make it simple, it's all about making pressure on particular points on the body in order to remove pain, achieve flexibility and the proper work of muscles.
In other words, there are Golgi tendon organs in fascia, which are sensitive to the changes in muscle tension. Stimulating them from outside (by rolling) causes the decrease of intramuscular tension and their relaxation. Moreover, rolling causes breaking the clumped muscle fibres. Those which occur inside fascia are the trigger points. Our aim is to find them and release.
They are sometimes easy to find, because they occur in the place of pain. However, it sometimes happens that the pain we feel is the result of radiating from another place of tension.
Rolling may be painful and it is definitely not the nicest activity. But remember, that pain should be bearable and you should feel better after rolling.
Why should we do something that causes pain? Isn't stretching enough?
Stretching is not enough. It's impossible to remove the trigger points during stretching and you don't relax your muscles then. Stretching, in a situation when you have painful trigger points, may be adverse. At such moment, it may contribute to extending one part of the muscle more than the other, which is why the intrafascial relaxation is not equal and you may overload some part of the muscle.
It's good to do the rolling, because releasing trigger points allows bringing back appropriate movement patterns and makes it possible to move without pain, which leads to bigger efficiency.
If you are able to to the movement properly without pain, your work is more efficient.
It is visible especially while doing squats. Tight fascia makes it impossible to do proper deep squat.
Working on releasing trigger points improves the technique of this exercise.
Rolling also helps to bring back the proper blood flow. By improving it, you will be able to provide nutrients to the tired muscles after workout. You will speed up the recovery time and you will make the relaxing time more valuable, therefore, you will gain power for further workouts.
There are few techniques of using foam roller. It's good to know them and use them.
In the first method, you should do the rolling until finding a swelling/trigger point. In this place you can feel pain. You should stop there and keep the roller tight in this place for 1-2 minutes.
Another method requires rubbing the trigger point. When you find a painful spot, go deeper in it and move in two sides in small range of motion. Do such movements 10-20 times.
In the third method you should do a rotatory movement after finding the trigger point. Thanks to that, you can reach much deeper. This way you influence the outer and deeper parts of fascia. You can do such movement, for example when releasing tension in glutes with the use of lacrosse ball by rotating the leg outside and putting the knee on the mat, then lifting the knee.
You should annoy the trigger poits, but you should also remember not to limit yourself to those particular points, but to roll whole muscles or the whole bands of muscles connected with attachements. None of the muscles are isolated in our bodies, therefore, we cannot focus only on the painful spots. We should act comprehensively.
Which foam roller should I choose?
Foam rollers differ from one another with toughness, shape and the amount of beads. The tougher roller with more beads, the bigger pain you can feel during rolling. Those types are advised for more advanced people and for treatment therapy. The softer rollers are advised for self-massage or strengthening training. It's good to choose a softer and more delicate roller at the beginning. With time, you can start using tougher roller with beads.
Rolling with tough roller may discourage the beginners, as well as it may contribute to avoiding the painful spots. In such case, rolling becomes ineffective.
To sum up, foam roller may help us remove pain, bring back the flexibility of muscles and make it possible to do the proper full range of motion in exercises.