By SUSAN CALLAHAN, Associate Editor and Featured Columnist
As I get older, I sometimes catch myself taking inventory of the things I can no longer do that I used to do easily. The list grows longer every year. Being the curious sort, I have researched why is it that we tend to fall apart in some basic ways as we age. I mean, quite apart from general physical strength which I know we need to improve, why is it that simple motions such as getting up off the floor become so much harder. The answer, it appears from a growing body of research, is that certain very specific physical tasks start to deteriorate at age 65.
One of the most important physical skills we start to lose at age 65 is something called "cross midline" coordination. The midline is what it sounds like --- an imaginary line right down the middle of your body.
As we get older, starting at age 65, we lose the ability to do simple things like reaching with our right hand across our body --- cross the midline -- to the left side of our bodies. Or, reaching with our left hand to the right side of our bodies. Of course, we don't suddenly lose this ability all at once, unless we have a stroke or something, and most of us can still do this at age 65. But the amount of time it takes to accomplish this simple task gets loner and longer as we age.
Why Crossing the Midline Is So Important to Your Overall Brain Health
We've all seen those movies where a police pulls over a driver, orders them to get out of the car and walk a straight line to see if they are drunk. They may also ask them to stretch their arms out and then try to touch their nose with the index finger.
Well, the reason these tests are used at all is that science has shown that alcohol slows down your brain's ability to coordinate your body's movements. Alcohol also makes it harder for us to know where are body parts are.
Aging affects the brain in a similar way. As we age, we lose more and more of the ability to coordinate our body parts, to know right from left and vice versa.
Something Magical Happens to Our Brains at Age 8
This ability to coordinate right and left wasn't something we've always been able to do. In fact, from the time we are born up until around age 8, most of us lacked the complete ability to coordinate our left and right halves. When asked to touch a knee or another joint with a hand on the other side of teh body, children at age 4 often simply use the hand and the knee on the same side of the body, according to studies led by Dr. Sharon Cermak of the University of Southern California.
The reason this is so is that our brains are made up of two hemispheres, the right and the left. Taking your left hand and placing it on your right knee may sound like an easy thing to do but it actually is an intricate complex coordination of bran circuitry. The same goes for using your right hand and taking it across your body.
Scientists call this ability "cross lateral integration". And the inability to coordination across your body either totally or partially or slowly is called "cross lateral inhibition".
At Age 65, Cross Lateral Coordination Falls Off a Cliff
After we learn to integrate our left and right sides at age 8 or 9, pretty much all goes well for the next 50 years or so. That is, until age 65.
At age 65, we start to revert back to childhood in a sense.
We begin to lose our ability cross lateral integration abilities, according to a 2000 study. The study, called " Age Differences and Changes in Midline-Crossing Inhibition in the Lower Extremities " was led by Dr. Julie Lombardi and Dr. Paul Surburg, both of Indiana University.
The interest in midline integration problems dates back to 1920 when scientists first noticed that brain damaged adults had trouble doing motions that crossed their midlines.
The Indiana University study showed that people over age 65 are much slower in performing body crossing movements. These are any movements that require you to reach across or step across or even look across your midline.
Work on Improving Your Ability to Cross Your Midline
Here are a few simple exercises that you can do at home to help to retain your ability to coordinate across your midline:
1. Look Sideways. Crossing the midline includes the ability to look across your midline. Practice by first sitting straight up and looking straight ahead. Then slowly turn to look over your left shoulder to your left. Return to the center.
Then slowly turn your head to look over your right shoulder to your right. Don't strain your neck. Do the motion slowly and smoothly. Repeat 8 times on each side every other day.
2. Touch Your Knees. While standing and looking straight ahead, use your right hand to touch your left knee. Return to center.
Now, use your left hand to touch your right knee.
Repeat this exercise 8 times per side every day.
3. Touch your shoulders. Use your right hand to touch your left shoulder. Return to center.
Then use your left hand to touch your right shoulder. Repeat 8 times each day.
4. Close Your Eyes and Touch Your Knees. Repeat the knee exercise with your eyes closed while sitting down.
Sports and Activities That Train Cross Lateral Integration
Ping Pong (table tennis)
Doing the Twist dance (dust off the old Chubby Checkers tapes or look him up on youtube)
Playing "patty cake, patty cake, baker's man" the children's game.