Training Quiets Aging Reflexes

Special exercises on a wobble board targeted muscle fibers and motor neurons associated with their gastrocnemius and soleus muscles, which are the calf muscle and the muscle immediately beneath it. These muscles are important for balance because they help people stand upright.

The special exercises were designed to help the participants, ages 80-90, retrain the 1a sensory fiber and motor neurons in the spinal cord in an attempt to have subjects rely less on reflex corrections, which are involuntary, and more on cortical control from the brain, which is much more effective at controlling balance.

Koichi Kitano, a doctoral student in the Department of Kinesiology in IU's School of Health, Physical Education and Recreation and the Program in Neuroscience, said he and his colleagues determined that after training, the reflex measured in the soleus muscle showed little change, but that the changes measured in the gastrocnemius were "significant."

Background: This study is part of a larger research effort by motor control experts at HPER to develop a screening technique that could alert older people to their increased risk for falls. Falls involving a broken bone can be fatal and also can result in a dramatic decline in mobility, health, independence and quality of life as the person changes her lifestyle to avoid more falls. IU researchers have recently found that a psychological inventory that probes such things as planning strategies and short-term memory is surprisingly effective in predicting balance ability. 

Kitano's study involved 12 people who participated in a 45-minute balance class three days a week. In addition to stretching and strengthening exercises, they spent 15 minutes of each class using a specially designed wobble board to target the postural and balance muscles.

This research was presented on November 4, 2007 at the annual meeting of the Society for Neuroscience in San Diego.