Detecting functional contralateral deficits in acceleration (force) pattern in soccer players: chronic groin injury.

This another example from an amateur spanish soccer player from FC Cambrils (Tarragona), in which after an standard training session and the corresponding analysis, we have detected some contralateral functional deficit in the acceleration (force) pattern on different axes, but specially in the contralateral one. After detecting it, I have ask the player if he was suffering any special problem, injury or whatever, and the answer has been that after some months, he is suffering from a chronic groin injury.

Hope you enjoy,

Detecting functional bilateral deficits in acceleration (force) pattern in soccer players: chronic patellar tendon pain.

Today you can see some data related with the detection of a functional bilateral deficit in acceleration pattern in an amateur spanish soccer player who is suffering from a chronic patellar tendon pain. In this case, this deficit is detected during the execution of a typical finishing task, in which the player must do an sprint to win the ball and try to score goal.
Usually it is necessary to look in all three axis of the acceleration data, but then the deficit can be detected in one or more axis, in this case you will see it in the vertical axis during the propulsive phase.

Next post we will see some data of another player who is suffering from adductor chronic pain.
Enjoy and stay tuned,

Detecting functional bilateral deficits in acceleration (force) pattern in soccer players: maximal speed (Part 3).

And here it comes the 3rd part of this issue.
As I have had so many requirements about this issue, After this post I will show you some more data in which you will see the detection of other functional bilateral deficits in acceleration, but this time associated with other sort of physical problems.

Enjoy and stay tuned!!!

Detecting functional bilateral deficits in acceleration (force) pattern in soccer players: maximal speed (Part 2).

Wow! A lot of expectation about this issue, some friends and colleagues consults, and also some professional work offers from all around the world confirms my initial thinking that this could be a future trend topic issue for at least some professionals working on sport performance (not only soccer).

As these is going to be a long familiar weekend (so busy!!!) I just share with you this 2nd part of this issue in which you will see ... better you go for it.

Enjoy!

Detecting functional bilateral deficits in acceleration (force) pattern in soccer players: maximal speed (Part 1).

As I supposed, it seems that this issue (and previous) has "wake up" the interest of lot of people around the world, not only in the net, and I'm getting so many invitations to explain and deepen on it in different forums (universities, federations and clubs, mainly), so just give me the chance to thank all of you for it.

And it arrives the moment, after a previous introduction of the issue, of sharing with you a series of videos where you will see how it is possible to detect (under specific circumstances) some functional differences between the acceleration demonstrated supposedly by each leg (IMPORTANT: remember the limits of the technology and methodology ...), and monitored by a GPS integrated system in some amateur and professional soccer players when training and competing.

I will start with an intro, and then with the first data related with some horizontal acceleration in the propulsive phase.

Hope you enjoy!

Detecting functional bilateral deficits in acceleration (force) pattern in soccer players: maximal speed (Intro).

After this long series of posts where we have analyze some data related to the collective metabolic power exertion of professional and amateur soccer players in training and competitions, it's time to go to another issue.

This lasts two months I have been talking with some friends and colleagues working in different professional soccer clubs in Spain and around world, and one issue that seems to be of some interests for more or less everybody is the prevention of injuries.

Also recently I have had the opportunity to assist to the 4th MuscleTech Network Whorkshop, celebrated in Barcelona by FC Barcelona, in where there have been presented some works related with this issue, and also where some of the bests world specialists in analyzing and preventing injuries have stated that actually there exists some doubts about the injury prevention methodologies, given that after implementing different protocols in top level european soccer clubs during the lasts 10 years, it seems that the  number of muscle injuries suffered in training and competition are more or less the same than in past years ...

Here we will analyze some acceleration data measured by the triaxial accelerometer that it's integrated in the GPS unit, given the direct relationship between acceleration and force applied. It's important to check that this short of analysis has it's own limits, as for example the relative position of the GPS unit (so the triaxial accelerometer position) with respect of the body of the player (usually not so close to the center of mass), and the ground (in some movements and some accelerations its not "perfectly" perpendicular to the ground, and what that implies ...).

And if we detect any functional bilateral deficit that doesn't means that a injury is going to happen!!! It is just showing us that something happens ... 

Therefore, all this means that we have to be careful when handling this information.

So what I have done is just to prepare some data acquired (with the use of a GPS system) some years ago in professional soccer players, and recently in amateur players, in order to show you how we can detect if it could exist any functional bilateral deficit in the pattern of acceleration of the body, when training or competing.

This GPS system units incorporate a triaxial accelerometer that can measure its acceleration in the 3 axis at 100 Hz.

What is important to know is that as with any technological system of measure, it has its own limitations that have to be known (but this is another issue, not for today).

In any case, it's of vital importance to understand that this is just experimental data, so the methodology of use must be developed (this is one of the issues I'm working on), and that at the end, the main problem falls (as always in soccer!!!) in the decision taking, that is, how to act when detecting this short of info.

So here I just want to show you that it is possible to identify some functional bilateral deficits using GPS integrated systems in soccer training and competition, under some specific situations.

Stay tuned for the next video!!!

Collective metabolic power exertion in soccer training: recapitulation 2.

And here we go again ...!
The concept of intensity ... so many times confused by the concept of exertion, specially when talking in an intermittent environment.
A higher exertion can be experienced by the increase of one or more aspects of the intermittence:
- the intensity of the actions (basically closer to its maximum, and always related to speed, acceleration, metabolic power, mechanical power ...)
- the duration of the actions (clearly longer time maintaining a higher intensity during an action)
- the intensity of the periods of relative pause, that is, between one and the next action
- The duration of those pause periods between actions (key factor in specific training tasks and competition!!!)

With this in mind, we are now just checking out the collective exertion based on metabolic power, because during a game, and also when performing an specific training task (as small sided games and others ...), specially those more similar to games (so with more number of players participating), the conditional effectiveness depends not only in one or two physically generous players who always accept the challenge of giving to his partners all his physical power, but much more important depends on the collective physical exertion, which implies a balanced conditional demonstration between all the players of the same teammate.

This leads as to the point of having to differentiate between individual conditional demonstration, more related with the individual experience of fatigue and the possibilities of increasing the individual specific conditional level (this is the usual approach), and the collective conditional demonstration, that is much more related with the collective performance (so not only conditional performance but also how this conditional performance adapts to the collective tactical demands of the game or training task.

So we have seen the main characteristics of the phases of higher collective metabolic power exertion during games of professional and amateur soccer players, and also how this collective metabolic power exertions is demonstrated during some specific tasks performed during professional and amateur soccer training.

Once decided which specific task we want to propose to our players in order to develop any of the targets that can be acquired (technical, tactical - cognitive, conditional, volitive - emotive, socio affective, creative - expressive ...), and with the idea of getting them ready for the competition, we have to choose which is the better way (and usually there is not only one way ...), so the methodology to be applied in training.

In practical terms, maybe we want our players to be able to achieve one or more of this targets:
- demonstrate higher collective metabolic power exertion during the more stressful phases
- demonstrate longer phases of higher collective metabolic power exertion
- demonstrate more frequent phases of higher collective metabolic power exertion (so lees time between this more stressful phases)
- demonstrate higher collective metabolic power exertion during the lower stressful phases
As you see, we are just applying the intermittence concept to the collective exertion.

So at this point, we have to decide the characteristics of the task in order to achieve the target.
And one important characteristic to decide is the duration of the interval time of the task (of each repetition).
Basically there are two main approaches: the traditional one, that implies to use longer interval times or the more recent approach that implies to use shorter interval times ...
And now we have to remember what we have seen that happens when using some specific tasks in training, in comparison with what happens in competition.
In general, longer interval time leads to a lower collective metabolic power exertion average. Depending of the demands of each task (related with the number of players participating so how the individual player must perform conditionally during the task), we will also see a progressive decrement of the collective metabolic power exertion (for the more demanding tasks) or just more or less constant alternation of those more stressful phases.

But if we want to achieve the targets mentioned above, maybe is gonna be much more time saving to choose the more recent approach, that implies to use interval times adjusted to the capabilities of our team players to show a higher collective power exertion.
This approach becomes much more evident in those more stressful specific tasks, in which we want our players to be able to show a higher "exertion" based on higher intensity of the actions performed, on more frequent actions (less time between actions), longer actions if needed, and also more "active" low stressful phases (more intensity in the pauses between actions), and also when there is a clear conditional main target for a specific task.
In those other specific tasks, more related with longer number of players participating, so with a prevalence of a more "tactical" target, then we have to choose again:
- tactical development in specific high collective metabolic power exertion will need a shorter interval time duration (and of course to apply the proper characteristics of the task in order to be able to develop the wanted target! not only the interval duration time ...)
- tactical development in the specific conditions of the game should need more longer interval time duration, in which the collective metabolic power exertion will show a similar alternation pattern than that showed during games.

If not, what do you thing will happen if when you look for increasing the exertion (also the intensity of the actions) performed in a specific task, you propose longer interval time duration ...?
As we have seen, lower collective metabolic power exertion, less intensity of the actions, more time between actions ... so the opposite of the target wanted!!!

Remember, if you want intensity, then propose any task with the constraints that allow the players to demonstrate your target.

Hope this make you thing about our own methodology in order to improve it (if possible!!!).

Stay tuned!!!

Collective metabolic power exertion in soccer training: recapitulation 1.

After so many posts in which we have share some specific data about this issue in different specific activities as games, tactical games, and small sided possession and soccer games of different number of players (professionals and amateur players) participating and different rules and field dimensions, is time of a little recapitulation.

The original idea of all this work is to be able to propose a different than traditional approach for the specific conditioning of soccer players.

This more traditional approach is based on the general assumption that for the development of the endurance concept, there is a way based on the interval time duration of each, in this case, specific task.

So a first point to take into account is that we want our players to have a better endurance ... but, what we understand for this term "endurance" when we refer to the specificity? and specially when we refer to the characteristics of the competition (games and also the fact of playing games in non-complete recovered situation?

A basic common idea is just to be able to maintain all along the duration of the game the demands that competitions could impose to the players.

Not here the problem.

After this common idea about endurance, then it arrives another "hurdle" to go over: how to develop this "endurance" ...

To big issues with so many curves to go through!!!

Let's come back to the start point: competition.

We have seen how our players demonstrate their collective metabolic power exertion in competition. We have seen some of the characteristics of this specific exertion, related to it's duration and intensity, so at first, we have a picture of the direction we have to follow in order to achieve the main target: be ready for competition. That will mean that we have to prepare our players specifically for being able to maintain their collective metabolic power exertion at least under similar characteristics that are demonstrated during games, but probably we should be ready to try to increase their collective specific conditioning performance to a further step, and that means that our players should be ready to demonstrate or higher values of collective metabolic power exertion intensity, or higher values of its duration, or much more difficult, both aspects at the same time.

And all this during the game, and during consecutive games ...

To keep focus, despite we are talking about "endurance", we cannot loose the view of the hole picture, and that means also that related always to specific conditioning, our players show an intermittent pattern of activity, in which they alternate actions and relative pauses (so different levels of intensity and duration).

But about this actions, we surely want the players to be ready to perform them more intense and longer and more frequent ... really difficult, but this is the "idea" ...

So we want them to keep intensity both with exertion, and this is not so easy to do but also not easy to train specifically, because that requires using specific tasks with some characteristics that allows the players to demonstrate exactly this: higher intensity (not only exertion!!! That's a common mistake).

And here is where the evidence of the data recollected in professional and amateur soccer players, and shared with you, should make you reconsider if we are going to the correct direction ...

Stay tuned!