Relationships between foot muscular strength and plantar pressure, shear force, and lower back and dorsum pedis angular velocity in patients with diabetes：Examination using a new simultaneous measurement method of plantar pressure, shear force, and lower back and dorsum pedis angular velocity in four patients with diabetes

Abstract

 To prevent callus development in diabetics, plantar pressures and shear force need to be controlled, and these are related to gait and foot muscular strength. We verified relationships between foot muscular strength and plantar pressure, shear force and hip and foot angular velocity using a new system we developed to measure these parameters simultaneously. Plantar pressures, shear force and angular velocities of the dorsum pedis and sacral parts of 4 diabetics hospitalized for education in exercise therapy and diet therapy were measured while walking on admission and at discharge. Checker-kun（Nisshin Sangyo CO., LTD, Saitama, Japan）was used to measure the pressure between the first toe and the second toe to estimate muscular strength under the knee. Two patients with increased foot muscular strength showed lower yaw angle velocity at the lumbar part, and one patient with decreased foot muscular strength had higher yaw angle velocity at the lumbar part. Regardless of changes in foot muscular strength, pitch angle velocity at the dorsum pedis and shear force were increased. Decreased pitch angle velocity at the dorsum pedis might indicate steady walking. To secure steady walking, increasing foot muscular strength may be effective. The results suggest that controlling the manner of walking and selecting shoes as well as increasing muscle strength should relieve shear force to prevent callus development in diabetics.