Each step is considered a “programming” process: lifting the foot, deciding on the target point, and if nothing is moving on the ground, then placing the foot down. Scientists previously believed that this process did not require visual input, but new research proves the opposite.
According to this research, we need continuous visual images to assist in finding the exact point to place our foot.
Previously, scientists thought that scanning the ground was only necessary during the “planning” phase of each step and not essential for tracking the actual movement of that step. However, Raymond Reynolds from the Institute of Neurology, Queen Square, London, and his colleagues have demonstrated that vision is involved not just in the “programming” phase, but also in controlling the step itself.
The team investigated how people place their feet down during walking. In half of the experiments, they “locked” the participants’ vision as they lifted their feet off the ground. The result was that the participants missed their target when placing their foot down. But when vision was restored, foot placement accuracy returned.
The potential consequence of missing a step, of course, is a fall. The scientists hope that by understanding what controls this fundamental walking action, they can gain better insights into human discrepancies.
“The important thing is that by knowing how healthy individuals control their steps, we can understand what goes wrong in those with neurological disorders, leading to falls,” Reynolds stated.