There are no guidelines to help physicians choose insole stiffness for patients with diabetes.
Patients with diabetes and their healthcare providers face significant challenges in achieving disease control and preventing complications. Unfortunately, many patients with diabetes experience limb-related complications, which can result in foot and leg amputations.
The proper footwear and inner sole of the shoe can remove pressure from the feet of patients with diabetes, but there is no uniform approach in determining the best approach. In many cases, a patient’s body mass index (BMI) is used to determine the stiffness of shoes.
A new study published by the Annals of Biomedical Engineering provides assistance to healthcare professionals tasked with choosing proper footwear for patients with diabetes based on scientific evidence.
Prior research has found that the stiffness of the material in shoes corresponds with treatment response and the mitigation of adverse events; however, there are no set guidelines that lead to a proper decision, leading many physicians to rely on anecdotal and empirical evidence for footware decisions.
In the current study, the authors examined different bespoke polyurethane cushioning that is manufactured normally. These materials were observed to have the same qualities, but differ in stiffness.
The investigators performed various tests using a 3D printed heel and on the feet of 10 healthy patients. Pressure measurements were taken of the entire foot to determine the mechanical characteristics and cushioning properties of the insoles, according to the study.
The results show the importance of BMI when determining insole stiffness, because patients with a higher BMI need a stiffer insole to reduce pressure. The authors noted that different materials could be necessary for the right and left foot since pressure is not typically distributed equally.
The findings also show that optimal cushioning stiffness can reduce pressure resulting from standing and walking by 16% and 19%, respectively.
The authors found that the optimal material for walking and standing differs, with stiffer materials offering minimized pressure when walking. Physicians should consider different cushioning for highly active patients compared with sedentary patients, according to the study.
"Using different material to minimise [sic] pressure could further enhance the offloading capacity of therapeutic footwear and orthoses, as long as it doesn't have a detrimental effect on gait and postural balance," Dr Chatzistergo said.
The investigators note that additional studies are needed to create material selection recommendations for physicians. The results suggest that optimum stiffness could be determined without costly gait analysis and plantar pressure measurements, according to the study. These factors could greatly improve clinical management of patients with diabetes.
"Every 20 seconds someone in the world is losing their limbs to diabetic foot complications,” said researcher Nachiappan Chockalingam, PhD. “Our work focuses on prognosis and prevention of diabetic foot complications in addition to effective treatment options. We strongly believe that this study will influence the material selection process for any prescription footwear."