for such things Routines, walking are surprisingly complex. Biomechanics divides a step into phases. First there is the touchdown when the heel hits the floor. Next is his single support phase while balancing on that leg. Then roll your toes and swing your foot forward for takeoff.
All this contains mysteries. Researchers have long observed that when we walk, her planted leg bounces twice before swinging to the next step. That is, the knees should be bent and extended once when the foot first lands, then bent again just before takeoff. This initial bounce helps your feet absorb the impact of your body weight as you land on the ground. However, the function of his second bounce, a characteristic feature of human locomotion, has not been clarified until now.
and Physical Review E In a paper published last month, scientists at the University of Munich may have found the answer. By modeling the physical forces that cause double bounds in humans, we speculate that double bounds are an energy-saving technique for a species that has long prioritized endurance over speed. Now they think their models can help improve the design of prosthetics and robots, and may even give insight into the evolutionary pressures our ancestors faced.
“The foot is the key here,” says mechanical engineer Daniel Lenyewski, who led the study. Frankly, human feet are a strange thing in the animal kingdom. Humans have a 90-degree angle between their feet and legs, he continues, but few animals do. That is, most animals walk on toes or balls of feet, but we walk from heel to toe. Staying on is a mechanical challenge.
According to Susanne Lipfert, a sports scientist at the University of Munich and co-author of the study, our double-bounce gait pattern is different from a single bounce when running. While walking, the foot remains grounded for up to 70% of the step cycle, allowing you to maintain balance even at low speeds. But it comes with trade-offs. Less time to move forward.Counterintuitively, it means your body has to work Harder As you walk, recirculate your leg to the next step. “At first glance, it seems strange to aim for a gait that leaves you with little time to swing your leg forward,” he says.
Given all these challenges, how can humanity get around? Trying to model what every muscle, tendon, and joint in the lower body is doing at a given point in time A difficult, if not impossible, task that has for years limited even a mechanical understanding of how we walk. We discovered that human gait can be reduced to a single equation based on the foot motion of
To build the model, researchers reduced the foot and leg system to four joints: hips, knees, ankles and toes. Using data Lipfert collected as a graduate student (information about the force and joint positions of his 21 people recorded on video while walking on a treadmill), they measured the heel-to-toe stride of the foot. as if it were a simple object rolling on the ground. That movement is easier to understand than trying to explain the entire anatomy of the foot.
