This study determined differences in spinal-pelvic kinematics sitting on (i) mat (ii) block and (iii) novel 10º forward inclined wedge (ButtaflyTM) in a same-subject repeated measures cross-over design in 60 healthy individuals (34 females). Repeated measures ANOVA revealed statistically significant differences between sitting conditions and lumbar and pelvic sagittal angles. Both, the inclined wedge and the block seating aids reduced overall flexion, but the inclined wedge had a greater influence in the lumbar region whilst the block induced the greatest change in the pelvis. This may be relevant for seating aid design personalised to posture type. Statistically significant gender differences were identified in all 3 seating conditions with males adopting more flexed lumbar spine and posteriorly tilted pelvis. Females flexed less in thoracic spine when sitting on an inclined wedge and a block. These statistically significant differences between males and females may provide first explorative direction for bespoke seating aids design.
Keywords: lumbar; pelvic tilt; personalised design; photogrammetry; posture; seating aids; thoracic spine.