Effects of Different Inner Pressure of Air Insoles on Plantar Pressure Gradient and Pressure Gradient Angle

Abstract

Abstract Air insoles may be applied to improve peak pressure gradient (PPG) and plantar gradient angle (PGA) for reducing foot ulcers risk in Diabetes mellitus. Dynamic PPG and PGA distributions of air insoles are uncertain. This study investigated the effects of different air insoles on the PPG and PGA. A repeated measures study design, including three air insoles and two walking durations was tested in 13 healthy participants. PPG and PGA values at plantar region of the big toe (T1), first (M1) and second (M2) metatarsal head were calculated. The PPG was lower at 80 mmHg air insoles after walking 20 min in the M1. The PGA in the M2 increased at an air insole of 80 mmHg compared to 240 mmHg. At 240 mmHg of air insole, the 10 min walking had the lowest PPG in M1 and M2. Moreover, peak plantar pressure (PPP) correlated positively with PPG for all air insoles. PPP and PGA were negatively correlated with 80 mmHg air insoles after 20 min of walking. 80 mmHg air insole lowered the PPG, decreased PPP and increased PGA compared to 160 and 240 mmHg. A shorter walking duration lowered the PPG. Air insoles might decrease foot ulcers risk by concerning PPG and PGA.