Perceived discomfort and neuromuscular fatigue during long-duration real driving with different car seats

INTRODUCTION: Identification of the seat features that could improve driving experience is a main issue for automotive companies. OBJECTIVE: Long duration real driving sessions were performed to assess the effect of three seats (soft–S(1), firm–S(2) and suspended–S(3)) on perceived discomfort and neuromuscular fatigue (NMF). MATERIALS & METHODS: For each seat, the muscular activity of bilateral Trapezius Descendens (TD), Erector Spinae (ES) and Multifidus (MF) muscles of twenty-one participants was recorded during real driving sessions of 3-hours each lasting approximately 3 hours and following the same itinerary. During each driving session, participants were also regularly asked to self-evaluate their level of whole-body and local discomfort. In addition, an endurance static test (EST) was performed before (ESTpre) and after (ESTpost) each driving session to assess the seat effect on physical capacity. RESULTS: Whole-body discomfort increased with driving time for all seats, but this increase became significant latter for S(3). The highest scores of local discomfort occurred for neck and lower back. Contrary to S(1) and S(2), the duration of ESTpost was not significantly lower compared to ESTpre with the S(3). Interestingly, muscular activity of S(1) remained stable throughout the driving task which could be attributed to sustained muscular contraction, while muscular recruitment adjustments occurred for S(2) and S(3) from 1H00 of driving. This muscular compensation concerns mostly the right side for S(2) and S(3) but with different profiles. On the left side, the muscular adjustments concern only the MF with S(2) and the ES with S(3). CONCLUSION: Overall, our results demonstrated that S(3) could be considered as the most suitable seat to delay discomfort and NMF appearance.