Researchers at the Indian Institute of Science created footwear that can self-regulate the pressure distribution when a person walks, helping to avoid pain and friction that can lead to issues for people with diabetes. Patients with diabetes can have an abnormal gait, sometimes because of pain or numbness in the extremities, potentially leading to complications such as foot ulcers when shoes rub or otherwise damage feet. These new shoes contain several arches that snap back into position when pressure that exceeds a certain level is applied, helping to distribute the pressure evenly and avoiding excessive pressure and friction on any one part of the foot.
Patients with diabetes often experience a loss of sensation in the feet because of diabetic peripheral neuropathy, and this can affect their gait. With a healthy modern gait, the heel strikes the ground first, followed by the ball of the foot and the toes, and this helps to evenly spread the pressure over the whole foot.
However, for those with diabetic peripheral neuropathy this gait can be disrupted, leading to abnormal pressure in specific areas. Over time, this can lead to issues such as foot ulcers, which can be particularly bad because of the underlying diabetes. To combat this, these specially developed shoes contain numerous arches that can respond to the pressure of walking and help to redistribute it. The arches “snap” into an inverted shape when they encounter too much pressure.
“When we remove the pressure, [the arch] will automatically come back to its initial position – this is what is called self-offloading,” said Priyabrata Maharana, a researcher involved in the study. “We consider the individual’s weight, foot size, walking speed and pressure distribution to arrive at the maximum force that has to be off-loaded.”
The researchers claim that their solution is more effective than existing designs, some of which employ memory foam to make shoes less abrasive. “There are a lot of commercial shoe manufacturers selling costly footwear in the name of giving comfort using what they call memory foam, but we have tested them, and they don’t have the required characteristics,” said GK Ananthasuresh, another researcher involved in the study. “This footwear can be used not only by people suffering from diabetic neuropathy, but by others as well.”
One of the strengths of the system is its simplicity. “This is a mechanical solution to a problem,” said Ananthasuresh. “Most of the time, people use electromechanical solutions. Such solutions involve using sensors and actuators that can rack up the price of the footwear and make them very expensive.”
Study in Wearable Technologies: Self-offloading therapeutic footwear using compliant snap-through arches