Long-term whiplash-associated disorders, sickness absence, and disability pension following rear-end car crashes and associations with whiplash protection systems: a longitudinal cohort study

1. Older cars without WPS were linked to higher long-term WAD and PMI, especially in men. 2. WPS offer more protection to men than women in rear-end collisions. 3. Long-term WAD leads to sustained increases in sickness absence and disability days. 4. Newer cars without WPS still show increased risk for men. 5. Improved WPS design is needed to better protect women in crashes. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s12889-026-27404-2.