A quantitative comparison showed that the contours of the SIPT and J826 manikin are similar in the areas they share.
The SIPT differs from the J826 manikin in having a lower center of mass and a more concentrated mass.
In contrast, the SIPT is readily installed and measured.
Substantial discrepancies between the J826 manikin and SIPT arise primarily when the contouring of the seat interacts with the parts of the tools that have different shapes.
In the driver seat used in the Seated Soldier Study, the fixed, prominent lumbar support creates a very upright back angle measurement with the J826 relative to the SIPT back angle tool.
Like the H-point machine, the SIPT provides a reference point relative to the seat that does not account for body armor or body borne gear.
The ISO 5353 SIPT is similar in contour to the J826 manikin in areas they share.
The repeatability and reproducibility of the two tools is similar, except that the SIPT is more repeatable in seats with seat cushion angles close to horizontal and with both very upright and very reclined seat back angles.