The inclusion of mobility in the training unit has become an increasingly common practice in recent years, and gradually the ratio of different variants of the static form of stretching is changing in favor of mobility, which is certainly commendable. Several factors contribute to this phenomenon, including the long-term popularity of CrossFit and the associated demands for mobility. We can certainly also talk about the growing enlightenment of corrective exercise, where mobility belongs. Third in line, I see more interest from practitioners in their health, which they prefer over exercise. On the other hand, the concept of mobility is often misunderstood and the practical implementation is far from what I consider to be real mobility training, in any form (classical mobility, busy mobility, spatial mobility, etc.).
The aim of the article will be to clarify the experienced half-truths and to show a new, correct and, most importantly, effective approach to using mobility to improve health, performance and overall contribution to everyday life. I will also touch on the “ageless” issue of the harmfulness or benefits of flexibility training using a static form of stretching.
What is the difference between mobility and flexibility
At the beginning of the whole article, I would like to encourage everyone to think before trying to read and try to define both terms themselves. Can you define the difference? If so, the rest of the reading will be all the easier. Otherwise, I recommend reading the article several times at intervals of several days. Let everything rest in your head and don’t be afraid to contact me with specific questions.
From my own experience, I can say that mobility is often confused with flexibility, or even understood as the same concept. A large percentage of the training population does not recognize the difference, and therefore cannot choose appropriately when to include mobility and when to deal with flexibility (if at all). We will now discuss both terms in more detail, so you know what is what.
Flexibilityis a deadline for decades, and whoever is flexible is automatically healthy, as proponents of stretching say. There are many ways in which it can be defined, depending on the context in which it is used. I will analyze flexibility in the context of human movement and physical activity. Flexibility can be defined here in many ways, and I choose both traditional and modern approaches to deciphering what flexibility means to give you an idea of how the definition has evolved over time. For example, Wilson and Wood (1991), Shellock and Prenticc (1985), DeVries (1986) or Hubley-Kozey (1991) have defined flexibility as the ability to passively stretch muscle. Shellock and Prenticc (1985), among other things, came to a timeless conclusion in their study, which, in my opinion, they wrongly attributed to flexibility. This was the importance of flexibility in the context of injury. Both authors state that it is precisely flexibility that is crucial for the elimination of injuries if we get beyond the extreme range of motion during active movements. I will explain why I do not agree with the authors during the mobility analysis. This is closely linked to that finding.
Kent (1998) conceives flexibility as the ability to move a joint smoothly throughout its range of motion. Witvrouw et al. (2003) understand the flexibility of the passive range of motion and the whole team of authors also mentions the help of the sparring partner, gravity or aids to reach the extreme position of the range. Clark, Lucett, and Corn (2008) understand flexibility as the normal “extensibility” of all soft tissues that allow full range of joint movement. In this definition we see a certain complexity and development compared to the first two of the 80’s and 90’s. The closest is the “modern” modern definition, which takes into account the context of mobility that will be discussed now.
Spina (2019) perceives flexibility as the ability to passively stretch a muscle or muscle group to the currently maximum range of motion. It further emphasizes that flexibility means only the range of motion without control and emphasizes the inclusion of flexibility in the subset of mobility. It is the control of movement that is what should be the main thing, because without control we cannot adequately use muscles and tissue.
Other authors of flexibility studies point out that muscle contraction is naturally three-dimensional, and if we take into account the geometric axes of human movement that configure the muscle structure, we conclude that flexibility in the form of passive static stretching only occurs at one time. in one axis. And while, for example, we “stretch” the tissue around the longest axis, at the same time the tissue will shorten to two more. In particular, the physiological cross-section of the muscle is reduced and this causes a transverse “shortening”. Nevertheless, many experts still prefer static passive stretching to mobility (Clark et al., 2011; Pescatello et al., 2014). As a result, we do more harm than good and from this point of view I see static passive stretching as a suboptimal technique for health and performance. However, for someone who is really bad in movement (large shortening, restrictions, etc.), can benefit from virtually any technique in the very beginning, and thus also from this form of stretching. In the case of a specific group of the population (seniors, people after injuries), some movement is still better than none at all.
We can see that flexibility is so important in contextual meaning rather than on its own. Simply put, you can’t achieve active results with passive training. While it may seem at first glance that you are more “flexible”, the real impact on performance will be minimal because the nervous system is simply not stimulated enough to “tell the muscles” to keep the newly acquired range of motion longer and longer. ideally be able to use it actively. I will explain the relationship of the nervous system to the whole concept in the text separately, because it is a fundamental player in motion in general.
So what is the context of flexibility in the context of mobility? What exactly is mobility and what development has the definition undergone? We will say this in the next part of the article, where I will also clearly combine both terms into one interconnected definition. As with flexibility, a brief history, the development of the definition and understanding of mobility will be described to begin with.
For example, Wang and Cochrane (2001) define mobility as the ability of a joint to move within a given range of motion. Harvey et al. (2017) or Medeiros and Martini (2018) point out that the human body moves through rotations around joints and mobility means three-dimensional movement, see previous text.
During my preparation for the SFL certification in 2016, I defined mobility as preparation for movement through movement. And I saw it as an effective tool to prepare the body for any physical activity. However, I did not consider strengthening the final range of motion, which I will get to immediately.
In 2020, I had the opportunity to discover a completely new concept of exercise (FRC, Kinstretch), which, however, works with established procedures, but gives them a new context and a comprehensive form, as the author Dr. Spina says. According to its definition, mobility hides flexibility and, above all, control over the performed movement, which is an active process. In other words, we cannot achieve optimal mobility without flexibility and vice versa. And mobility can thus be understood as control over actively performed movement. Spina also emphasizes the expansion of the usable range of motion. By extension is meant the load on the end range of the currently executed motion. In the Czech language, such an understanding of mobility can be defined as “tension mobility”.
In other words, if we want to work to improve the range of motion, we must be able to control it and, above all, strengthen it. This is the only way to achieve a sustainable range, reduce the risk of injury and move performance forward. You will now see on what principle the whole system of tension mobility works and what role the nervous system plays.
The role of the nervous system during mobility training
The issue of the nervous system is so complex that it simply would not even fit into the content of a separate article, so only the most important thing will be described, especially for the purposes of practical use.
The central nervous system (CNS) is the part of the nervous system consisting mainly of the brain and spinal cord. The name “central” derives from the main function, which is the processing and integration of the received information and the coordination of all parts of the body on the basis of incoming stimuli. The CNS simply gives orders to other centers in the body (Purves et al., 2018). Along with this are many seemingly complex-looking terms, such as sensory (afferent) neuron and motor (efferent) neuron (motoneuron), interneuron, axon, synapse, neurotransmitters, neural circuit, and others. Sensory neurons are responsible for converting external stimuli coming from outside to internal stimuli. Specific types of stimuli such as vibrations are transformed into “action potentials” by neurons and the whole process of transmission is called sensory transduction. Sensory transduction in the nervous system usually refers to events that alert to stimuli, where the physical stimulus in the form of mobilization of the joint capsule is transformed into an action potential transmitted by sensory neurons (more precisely its axonal projections) to the spinal cord and brain, which evaluates everything (Abraira and Ginty, 2013).
For simplicity, the transfer process is as follows:
- stimulus (signal) → collection (of data) → sensory transduction → processing of “data” in the brain → “action” in the form of movement
It logically follows that if the stimulus is too strong, the CNS will evaluate the action as dangerous and the muscles, tendons, ligaments will be given an impulse to contract and restrict movement. In this case, there will be no progressive improvement and we will still be moving in the same range of motion. This is the case, for example, with swing movements, where, in good faith, only the limbs are swinged, but the effect is minimal.
Within tension mobility, it is mainly a gradual adaptation of the nervous system and communication with it through impulses. The purpose is to convince the nervous system of the safety of movement and thus obtain “permission” from the nervous system to continue and especially the hard-earned range, although it can be a few millimeters, to maintain in the future and use for example for squats or cranks. From this point of view, strength training is recommended after tension mobility, where new ranges can be loaded immediately and the organism will gradually appropriate them.
As a nice example, let’s take the situation of a hockey player who decided to start attending yoga classes in the belief of increasing “flexibility” and performance. By the way, yoga is a very good tool for improving the perception of the mind and body, however, in this context it will be taken as an inappropriate example mainly because it is not specific enough for specific purposes. Hockey players tend to be more stiff, and therefore, in good faith, reach for some of the passive forms of stretching, which may at first glance look more movement-based. Unfortunately, the intensity is so low here that the hockey player does not reach the required activation level, because, among other things, the real strengthening effect begins somewhere around 80% of the maximum voluntary muscle contraction. The body will learn to be more flexible, but the nervous system will not be sufficiently stimulated and the muscles forced to work in new ranges of motion. Related to this is the adaptability of soft tissues, especially fascia.
It is also important that, in general, people do not distinguish between usable and unusable range of motion. Deliberately try to “stretch” the front of the thighs in the step (see the following picture). It will be easy with the help of a hand. When you release your hand, watch as your foot begins to drop and it will be difficult to keep it. In this way, it is easily possible to describe the passive and actively usable range of motion.
Once again, our model hockey player comes on the scene, who wants to play faster, more dynamically and without the risk of injury. It is he who will benefit from the art of actively using (neurologically controlling) the range of motion, see the previous comparison. Muscles and soft tissues will suddenly work completely differently – increased motor control, muscle growth, regeneration and many other aspects.
Tension mobility (FRC, Kinstretch) does exactly what is described above, namely increasing the body’s capacity to move along with learning the nervous system how to control and monitor newly acquired ranges. This makes the muscles more contractable and more usable in a wider range of movements.
Before the selected techniques from the training protocol are shown and described, it is also necessary to say a few words about the ratio between mobility and strength training. In general, the more I train, the more compensation I should give the body. For responsible professional athletes, the ratio is 1: 1, sometimes even more. For those who only want performance on their body, the ratio is completely different, often approaching the overwhelming predominance of training only. Openly speaking, until nothing goes wrong, there is no need to deal with compensation. From my own practice, I can talk about numerous problems, for example, in the general population with sedentary jobs who perform CrossFit several times a week for several years. Almost everyone who worked with me as part of the remedy confirmed the pain, limitations and injuries after only a few months of exercise, when after the “euphoric” part of which is the stagnation associated with the discovery of a segment of the body that is no longer willing to take large training doses. With increasing time and further training without adequate compensation, the risk of injury will only multiply.
Tension mobility – basic training protocol and recommendations
First of all, it is necessary to say that what we start with mobility training is crucial and it is always best to choose the procedure where we start either from the cervical spine downwards or from the ankles upwards. The so-called the segmental approach has been tried and tested for years. It is very easy to get on each of the main joints of the body and it is not a problem to choose more exercises even in a specific problematic place. The first thing to pay attention to is the joint sleeves and their surroundings, because it is the joint sleeves that not only stabilize the whole joint but also nourish it. Their health is so crucial. If the joint capsule does not work, the movement cannot be “healthy” and global muscle training will be risky. The technique that takes you to the level of communication with joint sleeves and joints is called complete controlled joint rotation.
internal rotation together with extension (taken in the direction of the arrows)
Efforts to achieve the widest possible range of motion will ensure a gradual adaptation of the joint and the surrounding tissue “moves”. However, you have to start really carefully and the best thing that can be done is to be tested before the exercise, how you are doing with active ranges. By no means do I recommend that you start with the ranges you see in the videos. On the contrary, the key phase is getting to know and ideally writing down feelings during exercise. Within the progressive approach, it is mainly a matter of increasing the usable range in the joints, and we will only achieve this by focusing on limited places. As for the selection of exercises, the following will be suitable for everyone except those with serious health problems. The best way to know if an exercise suits you or not is to follow a few principles.
The first principle is to be able to distinguish pain. If something so-called “snaps”, that’s fine, because the joints and joint surfaces are centered back into a natural setting. If there is a burning pain, it is necessary to stop and seek professional help. In short, even such an exercise is harmful in this direction and will not move you anywhere. The second principle is to have full control over the practiced segment. To do this, we use isometric contraction, where the whole body except the mobilized segment will be in tension. The tension will not only eliminate overlaps, but will also show the true range in a particular place. There will be no collisions and use of other parts of the body. The third and final principleis regularity. Yes, constantly practicing the same movements over and over again with increasing accuracy and quality is a condition for the general functioning of everything we do.
Selection of exercises
The basic variants of exercises will be demonstrated, which include the context of tension mobility and are suitable for the beginning of each training session or at any time during the day. The number of repetitions is highly individual, but from my own experience I recommend measuring the time around 30 seconds or performing 3-5 repetitions on one side, ie 2x 3-5 reps in the case of exercising each side separately (right and left). The last tip is to make the exercise as simple as possible and give the body room to adapt. This path is not the fastest, but it is sustainable in the long run.