Balance is the ability to maintain equilibrium when stationary, or moving, through the coordinated actions of our sensory functions ( vision,hearing, and proprioception ).
Comprised of ‘static’ balance – the ability to retain the centre of mass above the base of support in a stationary position, and ‘dynamic’ balance – the ability to maintain balance under changing conditions of body movement.
Balance is maintained as a result of the interaction of three systems : the visual, the vestibular, and the proprioceptive systems.
Vision plays a significant role in balance. Your eyes give you a picture of the world, and where you are in relation to other things in it. Approximately 20% of the nerve fibres in the eyes interact with the vestibular system.
The vestibular apparatus, an organ located in the inner ear, is responsible for maintaining general equilibrium. The vestibular apparatus exerts direct control over the eyes, so they can directly compensate for head movement. This is crucial in sports where tracking moving objects, or an opponent with head and eye movement is a constant necessity. Even standing still is an exercise in dynamic equilibrium. A person is swaying very slightly all the time to all four sides, and balance is maintained by alternate contraction and relaxation of the leg muscles.
When assessing balance, there are two key factors to consider : dynamic flexibility and strength. With respect to flexibility, it’s important to consider the athlete’s range of motion in the parts of his body that are being tested in order to properly load the muscles to allow balance to occur. For example, if an athlete performs a single – leg forward reach in the sagittal plane, and at a certain point in the movement he loses balance and has to step out of it, it may be assumed that he does not have good balance in the sagittal plane. However, if you look closely at the athlete’s ankle joint, you might find that it lacks the proper amount of dorsiflexion to allow the balance reach to occur. It is this, then, that limits his ability to perform the movement.
Strength can also limit dynamic balance. If the muscles do not have the strength to eccentrically decelerate a motion, the athlete may not be able to control his position, and thereby regain balance and change direction in a truly agile manner. For example, a tennis player who is running cross-court to play a backhand, and who begins to decelerate to set up the return shot. If he does not have the strength to control eccentric loading on his body to slow movement, or to load the legs, hips, and back in rotation to set up the backhand, he will be out of balance, and unable to respond with a powerful return shot.
In the body, muscles comprise a continuous chain that attempts to overcome disturbances in the centre of gravity. The chain begins in the ankle. when a challenge of balance forces the body to lean forward, the muscles in the back of the ankle, the gastrocnemius, will contract to counteract this movement to pull the body back in balance. If balance is forced backward, the tibialis anterior muscle will contract, and work to pull the body back into the centre of gravity.
While standing on one leg, there is an increased challenge to balance from side to side, which will be counteracted by pronation and supination of the foot at the ankle joint. in some instances, the sway of the body will be too great for only the ankle to counteract the balance challenge. When this occurs, the muscles in the legs, hips and back counteract the movement. In this example of standing on one leg, breakdowns in strength and balance may be evident with lateral flexion of the trunk, hip rotation, poor spinal posture, or excessive arm movement involving shoulders and arms. The body will maintain or regain balance only if muscles act across all joints to hold the desired position.
Many athletes today are using balance training as an integral part of their overall programs, both for injury prevention and performance enhancement.
With balance training, the idea is to recreate and manipulate, in a controlled environment, what we do in an event or game situation.
Maintaining balance means having the centre of mass within your base of support, ie, with your trunk aligned over your feet. Our body is constantly responding to feedback, in order to maintain balance.
as well as the centre of mass, we have to appreciate the importance of the centre of pressure within the balance equation. Balance is a dynamic process which applies to everything we do, including walking and running, where we are perpetually losing and regaining our balance. The questions we have to ask ourselves as athletes are : How far out of the centre can I go? How far, and how fast can I load my system, decelerate those forces, and reel myself back in? And, am I able to deal with those forces and torques in all three planes of movement?
To understand the body’s dynamic balance capabilities, you need first to have some grasp of the ‘proprioceptive system’, which feeds back information about position, movement, and balance from the body’s other systems, including the central and peripheral nervous systems. It has been shown that generally, the ankle is the dominant source of corrective action to maintain balance. However, under greater conditions of greater challenge – as with a foam surface, or eyes shut, there tends to be more corrective action at the hip and/or the knee. In other words, the more unstable the surface, the more compensatory action is needed further up the chain, in the knee, hip and trunk.
Balance training for your sport should involve replicating components of function associated with that sport.
We do not have to ‘switch the core on’ to provide balance and stability. If it is not switched on, there is a bio-mechanical explanation. And if your balance on one leg is worse than the other, it could mean something as simple as a tight calf or a stiff heel.
