Jon Divine, MD, professor of orthopaedic surgery at the UC College of Medicine and head team physician for UC Athletics, discussed the neuroscience behind hand-eye coordination for tennis players.
Q: What is hand-eye coordination?
A: Hand-eye coordination is a reflection of our reaction to avoid, or in tennis, strike an object. Exceptional hand-eye coordination is a skill that’s developed over time by athletes to hit a moving ball.
Q: How important is vision in hand-eye coordination?
A: Vision is our most dominant sense in terms of brain power required to process information. At least 30% of the brain is directly involved in processing vision. We estimate that as much as 85% of the brain could be involved in hand-eye processing.
Q: What systems in the body work together for hand-eye coordination? What parts of the brain are involved with hand-eye coordination? Lastly, what does your team do to help athletes improve their hand-eye coordination?
A: The 30-85% involvement of the brain in mastering hand-eye coordination consists of developing several vision and motor skills:
Simple vision acuity – how well you can see at near and far distances.
Photographic memory – the ability to initiate a rapid cascade of actions or movements based upon a split-second visual exposure.
Peripheral vision – ability to rapidly process what we see on the periphery of our vision field. Our primary theory is that by regularly doing vision training exercises, we’re improving an athlete’s ability to see and react to objects in their peripheral visual field. This enables them to protect themselves and reduce the risk of concussions.
Depth perception – not only how near or far an object is away from us, but also if the object is moving and in what direction and how fast it’s moving.
Vestibulo-ocular reflex – an involuntary reflex that controls eye movement to track a moving object. We perform several tests during a sideline or clinical exam of an athlete suspected of having a concussion.
Visual memory and motor memory – when we see an object moving towards us, we know from memory to duck, move or strike it. Like a tennis player returning a cutting serve, experience and memory enable the athlete not only where to strike the moving object but how quickly to adjust to different ball movements.
Faster twitch muscles equal a faster reaction time – the muscle controlling the eyes is primarily fast twitch. An athlete with a higher concentration of fast twitch muscles in their arms or legs will have a faster rate of concentration and movement than an athlete with a lower concentration of fast twitches.
Reflexes like a cat – in addition to involuntary reflexes involving eye movement and posture, we have involuntary reflexes linking our extremities and spinal cord. Those that react quickly to a rapidly changing target have both voluntary and involuntary input from the brain as to how to react and move most effectively.