DYNAMIC EQUILIBRIUM

The precision forward, and the proper stance or posture while moving backward allows the player to change direction at any given moment while going into, or out of the court's corners. Loss of dynamic equilibrium would impede the player from doing so. Even when the player stops into position and hits the ball, he is never still. There is always some part of his body moving. Hence, our great interest in dynamic, rather than static balance. In some cases, while a player is executing a shot and his legs seem perfectly still, it may seem that all he has to do is hold that static position while he hits the ball. Such reasoning is not realistic, as it does not take into account the movement of the player’s arms and shoulders. Therefore, some degree of weight transfer does occur and the player must learn to both counterbalance, and make use of these forces. However, most important of all, his muscle fibres must become sensitive enough to detect variations and respond accordingly. The muscle fibres can twitch and adjust; thanks to our body's built in sensors which fire impulses back and forth. Dynamic balance could be best understood as the management of unstable equilibrium. A finely tuned nervous system, which reacts at subconscious level, permits top sportsmen the ability to control movement. However, technique, co-ordination and posture are cultivated also consciously to achieve improvement. Posture is important because a well-positioned centre of gravity is the key to efficient movement.

Moving slowly to an easy ball may render the task fairly simple. But, what happens when the striker is coming in at full speed and has to hit the ball very hard? The notion of dynamic equilibrium becomes very important. In this case, the forces involved are huge and the athlete’s muscles and nervous system must be finely tuned to cope adequately. Also, a player must strive to have a low centre of gravity. Without a low centre of gravity, maintaining balance would become almost impossible and the muscular exertion would be immense.

Any aspiring player will have noticed the difficulty of making a good return when the opponent’s shot is clinging to the sidewall. The problem is compounded when the retriever has to move fast before actually reaching the ball. Without good dynamic balance, at worse the racket will end up in the changing room bin. At best, the player will mishit the ball. There is no point in being the fastest on a squash court when every tight drop shot is retrieved into the middle of the court or results in a stroke awarded. Being fit and fast is only rewarding when the quality of retrieving permits the player to regain some control of the T.

defined, tested, and improved in academic terms? This refers us to the work done by Prof. Dario Riva, Director of the department of research at the Scuola Universitaria Interfacolta` in Scienze Motorie di Torino.

Subjects are tested on a single axis balance board equipped with sensors. The sensors are capable of graphing the inclination of the board. The graphs are updated constantly with no time lag on a screen in front of the subject. The visual feedback permits the subject to make a much greater number of adjustments per second compared to the same conditions without the graphs. The task may become easier but the benefits are much greater with visual feedback. The greater number of subconscious adjustment processed by the archaic part of the brain provide the greatest benefits in terms of unstable equilibrium management. 

Photo courtesy of

Delos International

There are three distinct methods for "regaining equilibrium". (Regaining equilibrium is stated as opposed to "maintaining equilibrium". This is more accurate, as conditions are always changing as the balance board oscillates. "Maintaining equilibrium" may be misinterpreted and thought to imply static conditions. As we are discussing unstable equilibrium management, referring to constant adjustments to regain equilibrium renders the concept clearer. Note that in most cases, a good athlete will make micro adjustments that may make the position seem static. In reality it is dynamic and changing.)  a) The use of the arms to counterbalance the board's inclinations, b) the use of the upper body and hips to readjust the body's centre of gravity, and finally, c) the use of the leg joints to adapt. This final method is the most refined and precise of the three, and used by top sportsmen. The nervous system and its interaction with the muscle cells, to twitch, adjust, and reposition the joints, all occurs at a local level without conscious intervention by the brain. The adjustments are also minimal, but most frequent, permitting the subject to maintain the original posture. Hence, rendering it the most refined management system. 

In order to achieve the most amount of neuro-motor stimulation in the legs for optimal unstable equilibrium management, the subject is instructed to place the hands onto his hips to exclude the use of the arms as a balancing agent. A sensor is placed on the spine, just below the neck. This sensor gives instant graphic feedback on the screen in front of the subject. The graphs indicate any sideways inclinations by the truck. The subject must try to eliminate such compensation. That is, use of the upper body and hips should be excluded in order to rely on the lower limb as the sole management system working together with the visual feedback. 

This is just a brief summary of professor Riva's work. The professor's work also explains and tests the benefits of combining dynamic equilibrium exercises with weight training to achieve greater gains. More information could be found at www.ilfisioterapista.it

moving and the court floor is stable, parallels could be drawn and useful insight is gained. The work carried out in the laboratory confirms:

a)      The importance of posture and a correctly positioned centre of gravity. For example, try staying on the board while constantly leaning to one side or backward. The task becomes almost impossible. Compare this to correct posture, which must be maintained during acceleration off the T, entry and exit into the corners.

b)      The interaction between agonist and antagonist muscles. Opposing muscles and muscle groups together with stabiliser muscles work to manage balance and posture. If the interaction is excessive while a player is on court, fluid movement is hampered. Hence, the importance of relaxation. The system must be finely tuned so that only the least indispensable muscle fibres must work to manage balance, while only the interested specialised muscles must work to propel the player into the desired direction.

c)      Unstable equilibrium management can be achieved with great energy expenditure (if the arms, upper body, and hips are utilised), or with minimal effort if management is finely tuned and limited to the legs in association with correct posture and useful visual feedback.

d)      During a situation of unstable equilibrium, a far greater number of nerve impulses are firing and interacting with the leg muscles for prompt readjustment, than during a situation of static balance. This infers that remaining on the heals of both feet with legs well bent produces a position that is too static and unfavourable for reflex reactions off the T.

e) Finally, but probably most important of all. Dynamic balance management through local                interaction between nerve and muscle fibres with the exclusion of our conscious thought process, underlines the importance of training to render a movement or stance automatic. Our sensory system works in collaboration with the most antique part of the brain. It is as if our muscles have a brain of their own. Hence, the importance of repeating an action and adopting learning techniques which permit the muscles to "feel" and "understand" what they are doing. Relate this to the advice given to coaches and players in the sections on technique and movement.

The section on training is full of exercises to improve fitness and court movement. If you would like to see those devised to improve specific dynamic balance, click here.

CHANGING DIRECTION

Squash is a fantastic game, full of tactics and trickery. Prompt reflexes will help a player survive. However, when it comes to changing direction, no amount of reflexes and power combined can substitute correct posture and balance. Directional change in this game is constant and very abrupt. A clever squash player must smoothen the harshness inherent to this game in order to reduce the effort required to chase the ball around the court.

In the sections above, the correct stance during each moment of every imaginable situation has been scrutinised. This small section will demonstrate that dynamic balance and the awareness of its importance at all times, is a key factor, in securing adequate court coverage. In other words, the player must manage his body weight and inertia through correct posture and co-ordination.

When playing an easy rally at a comfortable pace, each player is subject to directional changes. He/she may start off from the T, move forward to one of the corners, stop, then return back to the middle. On returning to the middle, he/she may pause for a fraction of a second, or immediately change direction and set off to a different corner. This type of directional change is the most simple, and is continuous during a match. When a player has a clear idea of where he/she should go, everything is smooth. The problem may arise when the pace of play is very high against an opponent who is clever at disguising his shots, or often uses deception with good skills.

Under such conditions, a player may start off in the direction of one corner, then suddenly have to adapt and change path towards another. In other words, the player must be able to cope after being slightly wrong-footed. At this point, it is important to realise that a player may go through a mental change of direction, too. That is, he may initially, for a fraction of a second, erroneously believe that the ball will end up in one corner, before understanding that it will bounce into another. An experienced player may often make such changes without committing himself in any particular direction until he/she has a clear vision of where he should be heading. Hence, the term, mental change of direction.

In order to cope best in any of the situations described above, there are two rules to follow. The first regards body posture. The player must always incline the upper body slightly forward. This is most important, either when the player is standing on the T, or in motion around the court. At no moment in time should the upper body be allowed to rock backwards or lose this correct posture. The second rule is to be quick at taking the racket back and turning the shoulders. Even when wrong-footed, a player should recover towards the correct direction by first taking the racket back towards the side to which he/she intends to move.

In this example, the player believes to be on the receiving end of a shot in the rear backhand corner, before realising that he should move into the rear forehand side. Despite misreading the situation at first, he is hardly affected. His quick reflexes with the hand, and the delayed action of the feet, save him from stepping into the wrong direction.  

In this exercise, the trainer or coach is standing at the front of the court, giving indication towards one direction, then to another just after the player begins to move. In the first example, the player makes the mistake of leaning backwards to move to the rear.  

The following is an example of an initial forward movement, which is then changed, and the player goes to the back. Again,  the incorrect position of the upper body, slows down the player,

Leaning back to move backwards may seem like a good idea, but what would happen if  a player  has to  suddenly  change direction to

go forward?  

Another most significant disadvantage of leaning backwards or even to the side, is that an eventual counter reaction is produced. The result is loss of upper body control and an excessive rocking motion every time the player stops and turns.

The player is seen here, pushing off towards the backhand side. The correct position of the trunk harnesses the push developed by the player’s right leg.

In this case, however, the player is leaning backwards, and the right leg pushes only the hips towards the left side of the court. A great deal of energy is wasted, and the player would not be in a position to play an immediate shot on the backhand.