Previous Lecture Complete and continue  

  9.2 Saccades in Practice

Saccades

Saccades are another drill that are really easy to sneak into a yoga flow in a way that most of your classes coming to you for a "typical" yoga experience may not even notice. There are so many positions we come into throughout a yoga class (or in a pilates mat class) that create two targets between which we can shift our gaze.

You can call attention to why you are having your clients do so if they are a group that appreciates getting into the why's and movement science, or you can simply ask them to notice what they feel, to notice what changes for them in the pose, when they shift from a static gazing point or drishti to a dynamic gaze that toggles between two targets. This fits right in with the interoceptive work we often do in a yoga setting and doesn't have to feel sciencey/lecture-y or otherwise out of place in your class.

When I teach workplace yoga, I almost always dedicate time during warm up to visual drills (as you'll see in the sample warm up in the video) because the people I am working with generally have spent their whole day staring at a screen, with their eyes focused on a fixed (very close) distance, and making saccades for reading all day long, of course, but within a very small portion of the eye's total possible range of movement.

I might incorporate saccades again later on in the class, or they might just appear in the warm up. Wherever I use them, I build an eye rest or reset of some kind into the flow, too, before continuing on--so we ask the muscles of the eye to work in a way they maybe haven't worked in a LONG time, but then give them a true rest afterwards.

I always get comments of amazement when people do them for the first time about how good they feel, discovering muscles they didn't realize were there in the eyes, and headaches dissipating. This is good stuff!

Saccades also work really well in group exercise classes, personal training, and athletic coaching. But I wouldn't try to sneak them in within those teaching/coaching settings because they stand out so much from what we typically ask our classes/athletes to do. Help them understand why this will help them improve their performance, whether you are working with a middle-aged office worker who wants to stay fit to keep playing tennis with her kids, or a senior who has recently taken a fall and wants to be able to look down to navigate icy sidewalks while also seeing what is coming ahead of him, or an elite soccer player who wants to work on being in the right place at the right time so that she can head the ball into the back of the net.

Here's the key I share with my clients: Performance in athletics is determined not just by skill, but also by how quickly and accurately one's eyes can take in visual information to follow the target(s), while also taking in details about the rest of the environment, send that visual information to the brain for processing, so that the brain can decide what to do with the visual information received.

And we can train our eye muscles--just like we train larger muscle groups throughout the body--to be stronger through a greater range of motion and to move with more speed.

Field vision--in life but of course also in sport--is all about saccades. Our eyes simply can't move and process fast enough to keep up with the speed of a moving ball, so our eyes jump ahead, suppressing the information they are receiving in between points (saccadic suppressions) so that our brains don't perceive the world as a blur, then process information at the next location.


* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *


From THE IMPACT OF VISION AND VISION TRAINING ON SPORT PERFORMANCE

Duane Knudson, Ph.D., Baylor University and Darlene A. Kluka, Ph.D., University of Central Oklahoma

Journal of Physical Education, Recreation and Dance, April 1997. JOPERD is a publication of the American Alliance for Health, Physical Education, Recreation and Dance, 1900 Association Drive, Reston, VA 22091, USA.

http://dijq.sportsci.org/news/ferret/visionreview/visionreview.html

When there is slow relative movement between an observer and an object, the eyes can smoothly move together following the object until visual angular velocities reach 40 to 70 degrees per second (Bahill & LaRitz, 1984; Ripoll & Fleurance, 1988). In observing human movement, this translates to surprisingly slow movements, like a person walking (3 mph) slowly past an observer six feet away. Teachers who observe human movement need to remember that they usually cannot maintain visual focus on objects that are moving fast or close to them because of the high eye angular velocities required. In observing a gymnastic routine the teacher must observe one or two critical features of the movement rather than trying to track the entire routine

Most movements in sport require saccadic eye movements in order to observe parts of the action. [Emphasis mine.] Volleyball requires visual angular velocities in excess of 500 degrees per second to track the trajectory of a spiked ball (Ridgway & Kluka, 1987). Saccades can reposition eyes at angular velocities exceeding 700 degrees per second (Carpenter, 1988), but the eyes are essentially turning off as they saccade to the next fixation (Cambell & Wurtz, 1978). This is called saccadic suppression and is needed to prevent a blur of vision as the eyes move across the visual field. A simple demonstration of saccadic suppression can illustrate this missing field of view to athletes. Extend your arms in front of you about shoulder width apart with the thumbs extended vertically. Quickly change visual focus between thumbnails, noting what is missed between fixations.

It is possible that a person might appear to be focusing directly on an event, but did not see it because the eyes were essentially "off" between fixations. Saccadic eye movement ability tends to decrease with aging (Wilson, Glue, Ball, & Nutt, 1993), increasing the chance of a visual tacking error. The event might also not be seen because of a common eye blink (about 25 per minute) keeps the eyes closed about 1/10 of a second (Volkman, Riggs, & Moore, 1980). The more anxious an athlete is during a competitive situation the more frequently blinks occur (Volkman et al., 1980). It should be no wonder that occasionally an athlete misses an opponent's cut to the basket, drops a ball, or that an official's call creates a reaction in the crowd.



Discussion
0 comments