Plantar shear stress measurements — A review

BackgroundMechanical stress at the plantar surface has two components, pressure acting normal to the surface and shear stress acting tangential to the surface. Typically only pressure is measured and reported. However, plantar shear stress also plays a major role, especially in diabetic ulceration.MethodsDuring the last few decades, a variety of methods have been developed for the measurement of plantar shear stress. This paper reviews the technologies used in plantar shear stress measurements.FindingsSeveral technologies have been used, e.g. magneto-resistors, strain gauges, optical methods, piezoelectric materials and capacitive sensors. Examples of plantar shear stress values measured with the developed devices are also collected here and the relationship between sensor characteristics and the measured plantar shear stress distribution is discussed.InterpretationEven with the limitations of current plantar shear stress measurement technologies, they can provide useful information on the plantar stress distribution.