Shoes, sandals with an upward curve around toes may ease movement but can weaken foot muscles, study claims

Check out any jogging, running or walking shoe out there; no matter the brand, you’ll find toe springs as a key modern feature in most of them. Toe spring is the slight rise or upward curve around the forefoot of most athletic shoes and it’s what gives you a roomy feeling around the toes when you try a shoe on. It makes walking or running in those sneakers so much easier and more comfortable that we almost cannot imagine good athletic shoes without them. But a new study published in Scientific Reports suggests that this feature is likely to lead to deforming or painful foot-related problems. The study suggests that although most features of modern footwear have been intensively studied, there has been almost no research done on the effects of the toe springs. This is the first study to throw light on how toe springs affect the biomechanics of walking. Understanding the effects of toe springs The researchers behind the study argue that the upward curvature of the sole around the forefoot elevates the toe box dorsally above the ground and thereby holds the toes in a constantly bent or dorsiflexed position. This bending of the toes facilitates the ability of the forefoot to roll forwards at the end of each stance, making walking, jogging and running a lot easier and faster. To understand the effects of toe springs on foot biomechanics, the researchers collected data from 13 participants (nine male and four female) ranging in age from 19 years to 33 years with an average weight of 74 kilos and an average height of 182 cm (5.9 feet). All participants were healthy at the start of the study and had no injuries. The participants were asked to walk on a treadmill barefoot and then in four pairs of custom-made sandals with varying degrees of toe-spring angles. Each pair of these sandals had a toe spring curvature of 10 degrees, 20 degrees, 30 degrees or 40 degrees. The researchers chose to use sandals rather than shoes because of their relative ease of construction and, more importantly, they allowed them to place detailed marker sets on the feet of the participants. The cost of toe spring comforts The scientists found that the varying degrees of the toe springs did not have any significant effect on arch stiffness. They also found that the greater the degree of curvature of the toe spring, the less force the metatarsophalangeal joints of the toes had to exert to make forward propulsion easier as well as more comfortable. It is precisely because of this biomechanics that toe springs make walking, jogging or running more effortless and easy. However, the study indicates that this comfort and ease has its own cost. The researchers hypothesized that since the foot has to do much less work to make forward movement or propulsion possible, its endurance is likely to lessen with increased or prolonged use of shoes with toe springs. This may lead to the weakening of foot muscles as well as the metatarsophalangeal joints, which in turn can increase the risks of foot-related diseases like plantar fasciitis. Plantar fasciitis is an inflammation of the plantar fascia (the fibrous tissue along the bottom of the foot), which connects the heel bones to the toes. It is a common, painful and hard to repair condition. While this weakening of the foot muscles is hypothetical as per this study, the scientists behind the study insist that shoes with toe springs do alter the function of the foot and so, instead of wearing just these types of shoes, people should wear a wider variety of footwear - and also try barefoot shoes and running - to minimise the harm done by just one kind. For more information, read our article on Running.

Health articles in Firstpost are written by myUpchar.com, India’s first and biggest resource for verified medical information. At myUpchar, researchers and journalists work with doctors to bring you information on all things health.