In ball sports, two different individuals might receive the same sensory information about a ball travelling fast in their direction. But it is the ability to perceive information about the flight path of the ball before it moves that gives one an edge over the other. This ‘advanced perception’ allows him to anticipate where to move in order to intercept the ball.
Accurate anticipation relies on two forms of information:
1.
Prior information, based on knowledge of how a particular opponent tends to
operate
2. Detection of advance ‘cues’ that predict the direction and force of an
opponent’s response
Clearly, while most sports people will be able to gather the first type of information, access to the second type would propel that person into a different and privileged league. Here’s how:
When vision training was compared with physical agility training, researchers found that visual quickness or ‘anticipation’ can take the place of physical speed by buying the player enough time to start his move early.
When the two kinds of training are combined it creates an almost unbeatable outcome.
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In tennis, the ball has only around 24m to travel before it reaches the returner. When balls are travelling at such speeds it seems obvious that anticipation and the perception of important visual cues is vital. In fact, the evidence suggests that, for a ball served at 150kph, a responding player has only about half a second to determine the speed, direction and spin on the ball before organising and producing a response. Up against someone like Greg Rusedski, serving at 230kph, Agassi has even less time.
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If you know what to look for, you’ll see some players of other sports such as cricket; squash and basketball have similar skills. For those players the ball always seems to bounce just where they need it to make that winning move.
The analysis of sport is reliant upon
Dynamic Sensory Perception
Motor Response
You have probably heard the phrase ‘keep your eye on the ball’. Well, as I explain below, this won’t help your perceptual training much! It will however make facilitate fine adjustments in the late phase where adjustment to variable such as bounce occurs. But these are dependant upon early preparation, which in turn is dependant upon anticipation of gross location and spatial perception.
In tennis, when you watch the ball, it moves into your visual field and is detected by the eyes. This information is transported from the receptors via the optic nerve towards the central nervous system (your brain and spinal cord).
It is here that the incoming information is processed, as the stimulus is identified by comparison with past experiences, allowing for a decision on the most appropriate response. Once the movement sequence or motor programme has been selected, the motor neurones transport the relevant information to the muscular system, where information about the force and timing of muscular movements allows for an efficient response.
Although the above procedure happens very quickly, the novice or average player takes time to organise his response. He may seem fast, but he’s just not quick enough to beat an elite competitor.
Quite clearly, the ability to accurately perceive or anticipate what is about to happen, and when, provides the sports performer with a distinct edge over his or her opponents.
Vision training improves your ability to selectively attend to and detect important pre-shot (advance) cues that specify the kinematics of the opponent’s stroke. In other words, just before a ball is struck cues are available about body positions and limb movements that allow you to predict the direction and force of response.
The ProSportsVision report explains how best performers (the elite) focus on different pre-event cues in order to accurately anticipate what will occur.
During the execution phase, top tennis players concentrate more on the racket and holding arm than novices, who pay more attention to the ball. Elite players apparently need less information to identify the type of serve being produced -- and their speed of decision-making was quicker.
The evidence, together with examples from other sports suggests that the standard coaching advice to ‘watch the ball’ would cause the observer to miss important cues and fail to react rapidly.
Elite players focus on different sources of information, on shoulders, trunk and hips rather than the ball or the contact point. Thus it appears that the movements made by players when they are preparing to play a stroke are what the masters use to enable quicker responses.
The visual scene needs to be assessed. This requires peripheral and spatial awareness and then a perceptual interpretation/processing of the information at a subliminal level. This is achieving “the zone” where the processing is done without conscious thought processes and therefore allows the conscious processing to develop strategies and react to variation. At this level the players often don’t know how they got to the shot or in deed played it. It is simply a matter of intuition or natural ability. In fact this can be trained if the sensory acquisition of information is achievable.
The first requirement in elite performance is to acquire the sensory information. This can be trained and has little to do with static high contrast acuity such as the Snellen Test (20/20). (We have included a simple self test for visual acuity on the site click here to do the test). In fact a dynamic measure of the central and para-central visual field is required in order to pick up all the relevant cues, Arms, Legs, Ball Toss, Racket Path. These are all featured in the visual field but the eyes cannot track each and every one of these actions. Athletes have different levels of this dynamic sensory perception that allow for the ability to “recognise the game” and this is the primary process before being able to process the images and “read the game” or read the serve. Advanced studies in cricket have demonstrated by improving the Dynamic Sensory Perception of the central visual field it helps anticipation on events and allows more time in which to assimilate the information in order to make an appropriate motor response.
Vision Training in Sports it multifaceted but comprises
All of these need to be customised to the individual sport and athlete.
It is important that these are implemented in a method as close to the sporting environment as possible and integrated into a general training program. It is important that these enhance and are delivered in a positive format offering benefits rather than emphasis on a pre existing deficit.
Visual processing is taking the information and initiating the appropriate response. This is to a large degree natural ability or coaching strategies to play percentage shots or alter a game plan. This is outside the remit of vision training. However the improvement in visual training allows the earlier detection of the shot/ball and therefore enables greater time for the shot selection. The visual processing is subconscious and allows greater focus on the conscious decision of shot selection or variation.
The response time in performing the task is a neuro-muscular action. Improving the motor responses can be achieved by appropriate co-ordination exercises. Coaching fast and accurate limb movements is core to performance. This is a mix of bio-mechanics, nutrition and psychological effects. However training should be customised to an appropriate visual stimulation to enhance the neural linkage and pathway between sensory perception and motor response. Vision training improves accuracy of the motor response by more precise visual location assessment.
Tennis is a dynamic sports. Acquiring and processing the visual cues is the first process that requires analysis and training. Without the appropriate sensory inputs the natural ability or training of elite players will be limited. To allow a player to achieve their potential it is imperative that all aspects of play are optimised. Although their technique may be excellent if they cannot or do not see the ball as early as an opponent then their success may be suppressed.
You have to see it to play it.
Nick Dash BSc MCOptom. Clinical Director , ProSportsVision is Optometrist to the Lawn Tennis Association, and works with many UK Professional Players.
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January 14, 2006
