Validating force-estimating insoles for calculating centre of pressure and vertical ground reaction forces during occupational tasks

Force estimating insoles offer a mobile alternative to in-ground force plates for measuring ground reaction forces (GRFs) and centre of pressure (CoP) in occupational settings. However, their validity in measuring GRFs for occupational tasks has yet to be validated and CoP estimation approach has yet to be developed. This study developed this method for a three-compartment force estimating insole and introduced a force drift correction approach. Thirty-nine participants completed lifting, packaging, palletising, and above shoulder work tasks while wearing insoles on force plates. A weighted algorithm and linear drift correction were developed and compared against force plate data. The CoP method resulted in root mean squared errors (RMSEs) between 1.7 and 3.4 cm. Drift correction reduced ground reaction force RMSE by approximately 28 N. These findings suggest that three-compartment force insoles may be able to provide valid CoP and force estimates, making them a prospective tool for in-field biomechanical measurements of occupational tasks.