In order to achieve greater activation of the muscular and nervous systems, training on unstable surfaces is often used today. In this article we will try to explain what it is and highlight the usefulness of this type of training.
Training on unstable surfaces
In recent years, training on unstable surfaces has become a widely used tool both in sports centers, rehabilitation clinics and gyms. It is used to achieve all kinds of goals, relating to sports performance, health, injury prevention and sports rehabilitation.
When we talk about unstable surfaces we refer to surfaces used for the purpose of increasing the requirement for active stabilization. In fact, training in an unstable environment improves proprioceptive activity and the needs of neuromuscular control.
Definition of stability
Stability is “the ability of a body to maintain balance, that is, to avoid being unbalanced”. It is also defined as “the ability of a structure to return to its position when a disturbing force is exerted on it”.
Several authors share the idea that, in order to have adequate stability, correct functioning at the level is necessary:
- Muscle : to restore a state of balance we must have enough strength to do it.
- Neural : it is not enough to have the muscular structures trained to generate certain levels of strength, but we must also possess and manifest the ability to activate them at a certain intensity and at the right time.
Training on unstable surfaces primarily affects neurally. Despite this, to generate stability in the face of a movement performed in an unstable situation, we must first train the muscular component. In addition, training on unstable surfaces allows for good core activation.
It is important to know this, as we may have the neural component very well trained to stabilize a movement, but if we do not have the appropriate structure to do so, we will not succeed. This would create excessive joint load on the person exercising and can lead to injury.
Definition of equilibrium
In general, with balance we mean “the posture of the body that prevents falls”. It can also be defined as a “concept related to the forces acting on the body and to the inertial characteristics of the body segments”.
At the neural and physiological level, balance depends on three factors:
- Proprioception : proprioception provides us with information on muscle and joint structures.
- Vestibular : Responds to body movements through space and changes in head position.
- Visual : Refers to the system that provides visual information.
Effects of training on unstable surfaces
Many studies, including Behm, Drinkwater, Willardson, and Cowley, show that training on unstable surfaces increases core muscle activation more than training on stable surfaces.
Greater lumbar and abdominal activation can be explained by the need to stabilize the spine and maintain postural control. Therefore, according to authors such as Grenier, in situations of instability it is necessary:
- Greater activation of the central muscles.
- Increased activation ratio of agonist and antagonist muscles.
- More activation of the antagonist musculature.
- Additional need for joint stability.
- Pronounced joint stiffness.
- Less ability to produce strength and power.
Training in unstable situations offers a clear advantage. The cited authors explain that although force production with this type of training is reduced by instability, increased contraction plays a very important role in joint stability.
Instability for rehabilitation and health
From the point of view of rehabilitation and health, this type of training increases the possibility of reducing the incidence of low back pain. In addition, it helps to increase the sensory efficiency of the soft tissues that stabilize the ankle and knee. Therefore, this type of training allows you to:
- Restore the normal functions of the stabilizing muscles.
- Maintain or improve central muscle function.
- Facilitate proprioceptive re-education of injured lower limbs.
As for strength and power training, the increase in muscle co-activation produces a decrease in the production of force which, in turn, improves the stabilizing function of the muscles involved.
Instability in accident prevention
As for the effects of this type of training on injury prevention, numerous studies show the effectiveness of exercises performed on unstable surfaces.
Joint training with potentially destabilizing forces may be a necessary stimulus for the development of compensatory neuromuscular patterns that can help prevent lower extremity injuries.
For example, one of the conclusions drawn from the studies described is that training on unstable surfaces reduces the risk of suffering a lower limb injury by about 40%. This may be due to improved soft tissue proprioception or even improved balance.
Progression in training on unstable surfaces
Below, we show an example of training on unstable surfaces. This work is based on progressing from less difficult to more difficult tasks. This will make it easier for you to plan your training sessions.
- Support base (from highest to lowest).
- Movement speed, from isometric to dynamic.
- Associated motor systems (oculopedic and oculomanual coordination).
- Change of the regular balance system (visual system and position).
- Unstable surface: progression from greater to lesser degree of movement and level of instability.
- Media: from major to minor.
- Increased muscle tension with external resistance.
- Use of displacements.
All these variables can be introduced in isolation or jointly, depending on the specific situation of the person exercising. In any case, it is very important to customize the type of training.
Training on unstable vs stable surfaces
After this analysis, we can draw some conclusions about whether to train on unstable surfaces or, conversely, do it on a stable surface:
- Some studies compare core muscle activation through training on unstable surfaces with exercise without instability but with high loads. The results show that maximum activation is achieved through stable type training.
- A 2010 study demonstrated muscle activation of the vertebral area after performing a deadlift on a stable surface and an unstable surface. After analyzing the recordings of electromyographic activity, the researchers found that the best results in terms of force produced and muscle activation were achieved in performing this exercise on a stable surface.
- Most studies conclude that, at higher levels of external instability, there is less application of agonist force. Therefore, to improve the strength performance, it is necessary to have high levels of external stability.
- Regarding upper limb muscle activation, studies explain that triceps and deltoid muscle activation was greater with the push-up when performed in unstable conditions. However, no significant differences were found in muscle activation when performing these exercises on stable or unstable surfaces.
Not all studies have been able to demonstrate a higher level of electromyographic and muscle activation when performing exercises on unstable surfaces. Furthermore, it is important to know that muscle activation can be affected by the use of an unstable surface.
This circumstance is due to the fact that there is not always a greater activation of the muscles that participate in the movement.
First, you need to know what the real goal of the training is, then be able to choose whether it is useful to use this support as a complement, and never exclusively. It is worthwhile to properly investigate and analyze your physical situation, in order to understand if there are major advantages or disadvantages with this type of training.