The graduation thesis of Experimental Research on Exercise Physiology points out that the upturned shoes can keep the toes above the road, keep the posture of upward bending, and help the forefoot roll forward when squatting or jogging-this design scheme is mostly adopted in contemporary leisure shoes. However, their effects on natural feet and whether their feet are fragile have not been generally studied.
FreddySichting of chemnitz University of Technology, DanLieberman of Harvard University, NicholasHolowka of the State University of New York at Buffalo, and friends, used a group of control groups to study the harm of flip-ups to the sports physiology of feet. In the experiment, 13 participants walked barefoot on the home treadmill at a comfortable walking speed, and then were asked to put on clothes, especially the design scheme of 4 pairs of sandals. Repeating this whole process, the toe areas of these sandals will be inclined upwards in different degrees on the horizontal ground, thus simulating the bending degree of contemporary leisure shoes.
The author of graduation thesis uses trackers placed on everyone's knees, bare feet and soles to collect 3D fitness data. They found that upturned shoes would reduce the work of the whole body muscles connecting the toe and foot osteoarthrosis. The greater the upward force between the toes and the feet, the lower the work that the muscles of the feet can exert on the joints when walking.
The author of the graduation thesis said that the results of this study explain why upturned shoes are so comfortable and popular, but also remind that upturned shoes are likely to weaken the foot muscles under long-term wear. They believe that this may make the wearer vulnerable to common pathological conditions, such as plantar fasciitis, which links ankle fracture with toe inflammation.