The application of the motor control plan: from simple to complex, from the generalization to the specialization -> CHAOS.
The practical application of the concepts we’ve introduced to you in the part 1 of this chapter doesn’t imply a new and dedicated training session or a complete change in the rehabilitation/training processes; in fact, the ultimate goal isn’t even to create a program that is highly specialized in promoting changes in motor control or in motor learning but to adapt the point of view and mentality towards this component of injury prevention.
The goal of this 2nd part of the chapter is to help the reader to integrate what was discussed in the theoretical domain, with general and easy suggestions to put it into practice.
The neuromuscular training doesn’t directly improve the movement quality in specific sport tasks; therefore, there is the need to incorporate these tasks in order to maximize the coordination during the output tasks. This is achieved by training motor control in a progressive way as in, for example, small increases in the complexity of the movement. (Buckthorpe, Villa, et al., 2019)
There are always contextual differences in a spectrum that starts at the pre-planned gymnasium session, has the general coordination work in the field, and ending at the football match, with its specific movements and tasks (Chaos!!). These differences include the reactive nature of the movements, the surrounding environment stimulus and the requirements the decision making moment calls for (as mentioned before, the constraints).
Taking the example of a movement of acceleration and sprint to a free space in response to a long pass. The task on it’s own is the gradual increase of velocity in the change of position; however, this is mediated by spatial factors (location of the field, of the teammate, of the opponents, of the ball), temporal (pre-placement of the team mate, timing of the shot, timing of the run) and contextual (the good/bad recent form, the current result of the match, the duration of the match so far, etc.). These are the factors that create the chaos in which our athlete will decide, showing us how he’ll approach the acceleration/sprint.
We hope that, with this in mind, it becomes obvious that when rehabilitating a muscle injury, simpy checking if the athlete if capable of performing the acceleration and sprint effectively, will be misleading/deceitful (to say the least) if done in an isolated and controlled environment – not optimally contributing to the pretended end goal of this process: maximally reduce the risk of new injuries.
It is therefore mandatory, for a complete return to play, to include realistic environments into practice, both sufficient in quantity (number of exercises and repetitions) and adjusted to the unique set of skills/requirements of each player.
What can be manipulated?
The program should begin with a general coordination program, with a gradual increase in pre-planned movements (either single-joint or multi-joint) in a controlled environment as a gym and should progress through the simple linear running, followed by the introduction of curvilinear running and finally reaching the change of direction at peak velocity. This example of a progression is aimed both at facilitating motor (re)learning and increasing the confidence of the athlete in that movement.
After these pre-planned domains, introducing reactivity and agility (open tasks in which the movement occurs as the result of the external stimulus), passing through the retention of specific football movements, with or without the presence of an opponent.
Motor learning: practicing and assessment of the progress
Motor learning, as defined by individual capacity to acquire and retain new motor abilities, with a relatively permanent change in performance of a task or experience. The most common way of testing this is through the assessment of the resulting motor behaviour.
The instructions given and the additional feedback are important influencing factors that support this motor learning process. In almost all situations, athletes are instructed about an ideal movement pattern or technique. The instructional language – expressed as cues– has an influencing role both in the performance of the movement as well as in the outcomes of learning. As an example: instead of asking an athlete to straighten their back, asking him to show the chest team logo to the sky.
In order to obtain specialization and induce motor learning, a skill has to be repeated. For structuring this practice, some variables should be taken into account such as quantity, type and distribution throughout time. The best program isn’t the one that promotes direct effects in performance but the one that promotes long-term learning (good retention); even more important, the task-specific or task-centered practices should be done in order that there is a transfer of the skills towards the sport, while being meaningful, challenging and motivating to the athlete (for example: a competition strategy against himself or colleagues, time-trial against the clock, aiming for and recording the personal best, etc) (Gokeler et al., 2019).
The assessment of the progress is done continuously, without the need of a formal dedicated moment. It should always be done in order to maintain the ideal “ingredients” to learning and retention of concepts (the linguistic complexity of feedback, meaningfulness for the athlete, goal of the task defined while having in mind the final goal, challenging and motivating the athlete to the output), while being consolidated by repetition.
It should be noted, however, that even though there isn’t a need for a formal assessment (as seen during the physical examination). The variables that influence the motor learning process should be clear, as well as their influence in each moment and in the context throughout the program progression. Knowing these variables allows the professional to make an ideal structure of the sessions, facilitating the motor patterns in a form that is adjustable and transferable to a real situation and to their progression to the field work and the match day. Below, we present some of these variables:
|Difficulty of the task|
(Guadagnoll & Lee, 2004)
|This variable’s influence depends on the expertise level of the athlete, the complexity of the task and the training environment – all presenting an inverse relationship towards performance.|
Simple vs complex tasks: in simple tasks, a basic action pattern can be developed in few repetitions; however, in more complex tasks (with an increase in the range and plains of motion), the task could be initially divided in a series of independent subcomponents and build towards the complex task. It will take longer to excel and will take more effort as there is more information to process.
The exception of expertise:
The capacity of developing/learning versus the saturation of the motor learning system is defined by aspects like the level of experience of the athlete.The capacity of processing new information – a capacity needed for the acquisition and retention – depends on the difficulty of the task, and is also affected by the level of expertise of the athlete.
|It isn’t common to observe big increases in learning simultaneously with good performance. To maximize evolution, the task should be at the ideal challenging level that allows for growth, even if the moment doesn’t match with the ideal moment of performance.|
Practicing until the output movement is performed in a consistent, reproducible manner is the ideal process to potentiate the learning of complex skills.
The exception of expertise: For an athlete at their peak form, the goal could be immediate performance. For others, in which a margin of progression is expected, the goal should be to potentiate this progression, making sure the task is aiming at this goal while reaping the side benefits which still arrive from this strategy.
(Porter & Magill, 2010)
|This is defined as the practical interference of performance and learning of one task, in the context of others.|
A big contextual interference appears to be ideal for learning.
One example is the role of sprint training in the context of tactical attacking team drills. It should be obvious that this stimulus in a team and match context has a bigger benefit compared to the same stimulus while performed in a “no-context” situation, with “pure sprinting”. However, in an initial phase, the context may be limiting the ideal performance of the technical gesture (sprinting).
|Low contextual interference may be beneficial in a starting point of a new task, allowing the athlete to “get the feeling of the movement”. |
When the practice environment is adjusted throughout the training and the development of the skill, the athlete is getting challenged at the “sweet spot” needed to master the skill.
(Porter et al., 2015; Wulf, 2013; Song, 2019; Hill et all, 2017 e Schucker e Parrington, 2019)
|The attentional focus refers to what the athlete is paying attention to during the execution of the drill. This can either be an internal or external focus.The internal focus occurs when the attention is dedicated to a body region or the movement occurring in said region throughout the execution of the motor skill.On the other hand, external focus occurs when the attention resources are directed towards the effects that the movement promotes on the surrounding environment.|
Some studies found that the internal focus may facilitate the execution/performance in short sprinting actions (20m); in other words, the focus on components of the motor pattern and not on the “sprinting task” on its own.
However, other findings in runners who focused on the movements of running showed that these changed their usual patterns, becoming less efficient and with an increase in the vertical displacement and oxygen consumption.In coherence with these latter findings, several studies found increasing in the oscilations in kinematics and kinetics when an external attentional focus was used.
The exception of expertise:This higher effort economy resulting from the external attentional focus has been suggested to be experience dependent.
On a linear acceleration task, trialled in football players and sprints with the two separate focus conditions, it was found that, as the level of experience increases, so does the athlete’s comprehension of the action, developing implicit motor plans which reduce the effects external focus attention has on the immediate training session.
|When designing the training environment, it should also be taken into account the impact of the verbal instructions. The choice of words during feedback will define if the focus is done on the movement or the output.|
It is important to know the usual focus that the athlete uses in the specific task, before giving any advice on where to focus on.The variability of the issues of focus may be high (for example the length of the step, the impact on the floor or the competitive score) but the instruction should still be relatable and meaningful. The change of the focus may be done, according to the goal, the stage of learning, the motor response observed and the athletes feedback.
(Williams & Hodges, 2005)
|This variable consists in the presentation to the athlete of a “visual template” or “model criteria” for the desired movement pattern. In this way, the ability to clearly demonstrate the pretended goal is critical, since motor skills often require the retention of several details simultaneously (e.g.: velocity, aiming, form, etc). |
The demonstration will have a bigger effect when the strategy to perform is underlined and the athlete is physically fit and able to reproduce the action. However, over-demonstrating should be taken into account, since it may turn out to be restraining a fluid pattern of the movement, transforming it into a non-efficient movement for that individual (a classic error: the assumption that “one size fits all”). This reveals the difficulty in using the demonstration with the verbal feedback; there isn’t a well defined rule for the balance of these two but it often turns out to be more beneficial to start from the verbal feedback and then go for the demonstration.
|It should be taken into account that the visual demonstration may compete with the verbal feedback and that this last one should be meaningful for the task, with easy to interpret expressions and low chance to misinterpret them.|
Practical idea: Starting from a verbal demonstration and progressing to its demonstration, coherently and without over characterizing/over demonstrating.
|Feedback||Athletes should be seen as “problem-solvers” and not as passive information receivers. This should be taken into account, meaning that the feedback given should provide just the necessary input in order to “solve” the motor puzzle and increase the quality of the execution.|
It is suggested that with an increase in the performance of a specific task and with the athlete’s mastery, the athlete will be able to have a better precision with a lower rate of feedback; this will also change from a characteristic “prescriptive” from the start into a more descriptive at the end of the coaching.
|There is evidence that increasing feedback precision when implementing more difficult tasks or when looking towards specific changes to be made, leads to an increase in the performance. Athletes with more skill will require more detailed information in order to develop the performance in more subtle manners.|
|Planned vs Unplanned|
(Lucas et al., 2018)
|It has been found that introducing an unplanned action increases the inefficiency of the movement seen, for example, in the increase in the vertical reaction forces when sprinting. One example of an unplanned action is the reaction to external stimulus in a short time.|
These time constraints result in an increase in the demand of the musculoskeletal system, with an increase in the articular load and the muscular activation as a consequence; with this said, the demand of an integrated training (in the context of injury prevention) should be progressive, allowing for the adaptation of the other systems’ processing speeds (as will happen with the oculomotor).This overal system adaptation leads to increased efficiency and results in higher velocity of the neuromuscular responses, facilitating the avoiding of vulnerable positions, where injury is more prone to occur.
|In the rehabilitation spectrum of an articular injury, in which the load may be an important limiting factor, this variable can be manipulated in a later phase; on the other hand, when considering a prevention spectrum or a rehabilitation in which the articular load isn’t key, these variables can be introduced in the initial/simpler/controlled phases|
With this (short) overview of these mindsets regarding the role motor control plays in coaching/rehab/prevention and manipulatable variables, we expect the reader to have a clearer idea of how these concepts can be integrated in the planning of each session.
To sum up, we believe that these concepts should be part of the reasoning throughout every moment (meaning that even in drills that have some other main goal) and not necessarily in one fully dedicated session. The answer to the title (the role of motor control in the muscle injury prevention) isn’t straight forward: for starter, to prevent muscle injury is virtually impossible. However, with these concepts in mind, you’ll be able to manipulate both the difficulty of the task as well as the transfer towards the field work and, along this process, improve the athletes’ performance, their rehab period and, eventually, reduce the risk of a more serious injury.
Authors: Bruno Rodrigues e Lucas Brink Carvalho
Special thanks for the bullet proof reading by: Tomás Correia
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