Autonomous driving will lead to a variety of non-standard occupant postures that will require novel countermeasures, such as adaptive restraints, which will require sensing of occupants’ dynamic repositioning. This study aimed to understand if loads under the vehicle seat could discriminate occupants’ position during lowacceleration manoeuvres. Seat loads were collected for:​ (1) 16 forward-leaning adults restrained with high-force, low-force, or no pre-pretensioning (PPT) in a 1 g frontal impact;​ and (2) five nominally, moderately, and severely reclined booster-seated children in a 2 g lateral-oblique impact. Net magnitude and direction of torque on the seat were calculated. In the frontal impact tests, a significant effect of PPT level was found, showing that torque magnitude was greater with low-force PPT (290 ± 42 Nm) than with no PPT (251 ± 37 Nm) (p<0.0003), and with high-force PPT (291 ± 46 Nm) than no PPT (p<0.0002), with no significance between low- and high-force PPT (p>0.8). In the lateral-oblique tests, no effect of seatback recline angle was found (p>0.19). Occupants’ repositioning due to PPT in forward manoeuvres were detected by seat loads, but differences in occupants’ displacement in reclined postures in lateral-oblique manoeuvres were not. Future studies are warranted to explore different postures, countermeasures and loading conditions.