Effect of Shod Walking on Plantar Pressure with Varying Insole

Abstract

Walking and running are very critical factors in human being’s everyday life. A human being takes more than 2,000 steps to walk 1.6 km. The human being wear a boot with insole to protect feet when walking, playing and doing various activities. The boot with insole provides significant impact on the feet during these events and transmitted through the feet due to intense force and pressure. Measurements of plantar pressure are important for diagnosing lower limb disorders, designing footwear, injury prevention and applications in sports biomechanics. The objective of this study is to investigate the plantar pressure exerted on the feet during shod walking (wearing boot with three types of insoles); to identify effective insole for reducing plantar pressure during walking (wearing same boot with three insoles). Eighteen fits, healthy male adults volunteered for this study with mean and SD (mean±SD) age (36±9) years, height (169±4) cm, and weight (71±8) kg. During experiments, each volunteer underwent 5 min of treadmill walking (4.5 km/hr speed) with wearing of boot with varying types of insoles (Low-density polyurethane (LDPU) insole 1; High-density polyurethane (HDPU), insole 2; and Silicone rubber (SR), insole 3). Plantar pressures were measured by using a foot pressure measuring device. A paired t-test was conducted to observe significant changes in plantar pressures of different foot region (P<0.05). Observations of the present study revealed that plantar pressures (N/cm²*s) were minimum during the use of LDPU insole than HDPU and SR insoles. It was also noticed that during the using of LDPU insole, less plantar pressure observed in the heel (3.84 ±1.16 in right foot) followed by forefoot (right 3.92±0.88), lateral (right 3.56±0.85), and medial foot (right 3.60±0.69). Hence, the present study suggested that using LDPU insole reducing the transfer of impact forces to the body/foot in comparison to HDPU and SR insoles during walking and minimizing the risk of foot-related injuries in long term use.