A force platform for large human displacements

This paper provides details of a force platform assembly suitable for measuring the magnitude, position and direction of ground reaction forces for manual handling tasks involving several footsteps in any horizontal direction. An approach to increase the natural frequency with the use of a vibration absorber is used; this frequency was found to be 41±2 Hz. The results show a maximum error of 22 N (2% of the full scale output) when a person performs repetitive movements from a squat position to a full extension and back to the squat position. Static tests show the maximal errors to be, vertically, 1.5% of the full scale output (1818±33 N), and horizontally, 4.9% of the full scale output (1177±6 N).