Ocular Dominance in Snowboarding by Nathaniel Hammerli

Ocular Dominance in Snowboarding by Nathaniel Hammerli

 

How often do we, as snowboard instructors, witness riders turning down the mountain with their front shoulder and hips opened toward their heel edge, front leg extended and back leg more flexed, just to see down the hill?  I see riders of all ability levels, of every age, and in every type of terrain that ride this way, but why?   I have always heard the explanation that this riding style comes from a skiing background, and skiers are accustomed to looking down the fall line.  If this were the case, wouldn’t they have the same tendencies in their switch stance?  I have taught people to snowboard who have never seen snow prior to their lesson, and they still demonstrate these tendencies. Students have learned to ride in a nice aligned switch stance, in the same day that they began to turn out of alignment in their dominant stance.  There must be a more in depth explanation for this phenomenon.

According to Schmidt and Wiseberg, “Visual dominance is the tendency for visual information to supersede information coming from other senses during the process of perception.”  When your eyes are open, they are the most dominant sensory system.  Ocular dominance is the tendency to prefer visual input from one eye over the other.  The more trusted eye is referred to as the dominant eye.  The dominant eye, with its ability to process information milliseconds faster than its neighbor, plays a large roll in balance.  The brain relies on both the dominant eye and dominant side inner ear to make subtle adjustments in balance.  The information delivered to the central nervous system is used to coordinate, regulate, and control our bodily functions in response to various stimuli.  Neurological maturity is complete by late childhood and eyedness is fixed at that point.

In most cases, left or right-handedness (or left or right footedness) coincides with left or right eyedness, but this doesn’t always hold true.  Cross-dominance is when the opposite hand and eye are dominant (right hand and left eye or left hand and right eye). This combination seems to be advantageous in sports requiring side-on stances such as baseball, cricket, golf, and potentially snowboarding.  Approximately two-thirds of the population is right-eye dominant, and one-third is left-eye dominant.  Interestingly enough, these statistics hold true for all mammals.  Eyedness affects our gait pattern as well as our handedness.   The dominant eye makes minute adjustments in our line of travel. We take a slightly larger step with our dominant foot, and the toes of the dominant foot point more directly down the line of travel.  The difference in step or gait often causes a slight difference in muscle development.  The dominant side calf is often slightly larger, and the thigh of the opposite leg is slightly larger.  In addition, the shoulder on the dominant eye side tends to rest a little lower.  The later trait is very noticeable in many riders: rear shoulder slightly lower and head tilted to position the dominant eye to better take in the terrain.  These tendencies tend to disappear when the rider rides in a switch stance with the dominant eye closer to the action.  A cross-dominant rider’s dominant eye would be the lead eye in their stance; therefore, the tilting of the head and the shoulder should be less noticeable.  These physical differences are less noticeable in athletes who spend a lot of time training to overcome these dissimilarities.

Determining eyedness early in lesson can aid the instructors by making them aware of possible physical tendencies and preferences the rider may have. There are several simple tests that can determine which eye is the dominant if you are not yet aware.  The most popular is to form a triangle with both hands by overlapping your thumbs and crossing the knuckles of your index (pointer) fingers.  Choose an object in the near distance to focus on through your triangle.  Make sure that both eyes are open when focusing, then once you have the object centered in the middle of your triangle, take turns closing each eye, if when you close your right eye the object miraculously disappears, then you are right eye dominant.  If the opposite holds true, then you are left eye dominant.  Using the same hand made triangle, focus on an object in the near distance with both eyes.  Slowly bring your hands toward your face, remaining focused on the object the entire time.  Whichever eye your hands land on is your dominant eye.

We cannot change our dominant eye, but we can train our less dominant eye to be stronger.  There are many aspects of our vision that can be improved by exercising them. Peripheral vision can be improved with exercises that force the eye to focus on an object in front of you while trying to take in the sights around you.   As snowboarders, we are constantly looking over our shoulders to gather information from our blind sides.  Peripheral vision allows us to take in more information.  One simple exercise to improve peripheral vision involves holding your arm fully extended in front of you with your thumb sticking up.  Focus on your thumb while trying to decipher colors, objects, and actions going on around you.  A similar task can be done using your computer or television.  Focus on a spot in the distance slightly above the screen, or your thumb, while at the same time trying to describe to yourself what you see happening on the screen out of the corner of your eye.  Get creative; come up with some new exercises using what’s around you.

Contrast sensitivity, the ability to see differences in shading, is very important in the snow sports world, and improving your non-dominant eye can improve your contrast sensitivity.  There are studies that say playing video games can improve contrast vision as well.  Playing video games with your dominant eye closed could improve contrast sensitivity in your less dominant eye.  Simply closing the dominant eye while performing a task, such as snowboarding, can improve the less dominant eye.  Be careful with this one; remember the dominant eye plays a large part in taking in the information that aids in balance. Be sure that you are comfortable in your athlete’s ability; this exercise can be very intimidating to most.

Our body and mind can be trained to learn new things.  The more knowledge we have    as snowboard instructors the more successful we will be instructing others in the sport of snowboarding. Ocular dominance is not the only cause of how we behave on snowboards, but I believe it can be an important factor, and being aware of the effects will only enhance our ability to help others improve their riding.

 

 

 

Bibliography

Blakeley, Peter. “Understanding Eye Dominance.” Texas Parks and Wildlife. Nov.2006.
4 April 2011. www.tpwmagazine.com/archive/2006/nov/skillbuilder.

Griffiths, Geraint .”Eye Dominance in Sport.” 15 Aug. 2003.  6 April 2011.
www.teambath.com/wp-content/uploads/articleeyedominance.pdf.

Schmidt, Richard, and Craig Wriseberg. Motor Learning and Performance. Champaign: Human Kinetics, 2004.

Vallandigham, Paul H. “Eye Dominance and Your Body”. Wild Wood Tracking. 1994. 1 April 2011.
www.wildwoodtracking.com/limbdominance/pveyedominance.

“Video games’ can improve vision”. 29 March 2009. 6 April 2011.
news.bbc.co.uk/2/hi/health/7967381.stm