One foot in front of the other, back straight, arms swaying – walking is more complicated that we realized. Every step is different, says Kathleen Cullen, a physiology professor who performed a study on movement at McGill University. Her study found a pocket of motion-detector neurons that alerts the brain when the body moves in unexpected ways, such as tripping over a shoelace. The neurons trigger compensating reactions to keep the body upright. “The cerebellum is computing unexpected motion within milliseconds to send information to the spinal cord to maintain balance,” Cullen said.
Studying these neurons might help doctors better predict people’s risk of falling and improve athletic training and rehabilitation strategies, especially for the elderly.