A Device for Simultaneous Measurement of Pressure and Shear Force Distribution on the Plantar Surface of the Foot

Abstract

A device has been designed to simultaneously measure the vertical pressure and the anterior-posterior and medial-lateral distributed shearing forces under the plantar surface of the foot. The device uses strain gauge technology and consists of 16 individual transducers (each with a surface area measuring 2.5 × 2.5 cm) arranged in a 4 × 4 array. The sampling frequency is 37 Hz and data may be collected for 2 s. The device was calibrated under both static and dynamic conditions and revealed excellent linearity (±5%), minimal hysteresis (±7.5%), and very good agreement between applied and measured loads (±5%). Vector addition of the distributed loads gave resultant forces that were qualitatively very similar to those obtained from a standard force plate. Data are presented for measurements from the forefoot of 4 diabetic subjects during the initiation of gait, demonstrating that distributed shear and pressure on the sole of the foot can be measured simultaneously.

Estimating the complete ground reaction forces with pressure insoles in walking

“…However, the measurement is often restricted by the number and the 30 location of force plates. In attempt to measure vertical and shear ground reaction 31 forces without such restriction, different devices were developed, such as a thin layer 32 of strain gauge transducer (Davis et al, 1998) or piezoelectric copolymer film (Razian 33 et al, 2003), and instrumented shoe with two sensors mounted beneath the forefoot 34 and rearfoot (Liedtke et al, 2007;Schepers et al, 2007). However, these devices were 35 limited to its specific purpose and thus were not readily available for other researchers.…”

“…Line 32: please correct "...including a thin layer..." or even better, "...consisting of a thin layer..." >>> The paragraph lists some different devices, so it read "including a thin layer of strain gauge transducer (Davis et al, 1998) or piezoelectric copolymer film (Razian et al, 2003), and instrumented shoe with two sensors mounted beneath the forefoot and rearfoot (Liedtke et al, 2007;Schepers et al, 2007)". The term "including" is revised to be "such as" in the revised manscript.…”

Spectroscopic Study of Poly(Vinylidene Fluoride)/Poly(Methyl Methacrylate) (PVDF/PMMA) Blend

“…In the films of PVDF/PMMA blend before and after exposure to artificial weathering and to the salt spray it is noted that the bands at 510, 839, 880 and 1406 cm -1 are those of the β crystallinity phase of the PVDF [9,10]. The α-phase is identified by the presence of peaks at 763 and 948 cm -1 [11,12].…”

Estimation of Ground Reaction Force and Zero Moment Point on a Powered Ankle-Foot Prosthesis

“…Several investigations have compared the abilities of commercial in-shoe pressure measuring systems to accurately quantify vertical force and temporal parameters with measurements from gait lab and force plate measurements (Lawrence & Schmidt, 1997;Barnett, 2001). Previous work has also been developed to determine the pressure distribution in prosthetic interfaces, and for the measurement of the force and pressure distribution on the plantar surface of the feet (Williams et al, 1992;Davis, et al, 1998) Even though the in-shoe systems previously discussed allow the estimation of the vertical component of the ground reaction force, they have a major draw-back, which is the lack of direct quantification of the medio-lateral and anterior-posterior forces. Razian & Pepper (2003), investigated the development of an in-shoe triaxial pressure measurement transducers based on piezoelectric film components in order to simultaneously measure shear and vertical forces during gait.…”