Biodynamics and Discomfort of the Human Body in a Seated Posture with a Large Backrest Inclination Angle
Source abstract
Abstract
Large-reclined seating has emerged as a favored configuration in the luxury transport sector. While the static advantages are evident, the effect of this posture on dynamic comfort is not clear. This study investigated the objective biodynamics and subjective discomfort of the human body sitting in a large-reclined posture (58° from the vertical) under single axis vertical and lateral vibration excitations. The transmissibility of the human–seat system and apparent mass of the human body were measured respectively. The results revealed a critical transition between static and dynamic comfort: while the 58° posture offers superior static relaxation, dynamic discomfort dominates the overall perception when the excitation intensity exceeds a threshold of 0.249 m/s2 r.m.s. Objective measurements indicated that dynamic comfort degradation in large-reclined postures is primarily driven by altered inherent biodynamic characteristics. These findings highlight that future luxury vehicle seating must incorporate targeted dynamic isolation to compensate for posture-induced comfort degradation and ensure premium ride quality.
Source: crossref · Quality: baseline
Research context
OpenAlex topics: Effects of Vibration on Health · Ergonomics and Musculoskeletal Disorders · Pressure Ulcer Prevention and Management
SciVX discovery tags are terminology-based. OpenAlex topics are source-provided classifications.
Affiliations
College of Energy Engineering, Zhejiang University, Hangzhou 310027, China
MoE Key Laboratory of Human Factors and Intelligent Reduction of Vibration & Noise, Fuzhou 350109, China
School of Vehicles and Intelligent Transportation, Fuyao University of Science and Technology, Fuzhou 350109, China
Funding
National Natural Science Foundation of China · Zhejiang Provincial Natural Science Foundation of China
References (48)
Show source-provided references
1. A study on biodynamic models of seated human subjects exposed to vertical vibration10.1016/j.ergon.2006.06.008 ↗
2. The apparent mass of the seated human body: Vertical vibration10.1016/0021-9290(89)90031-6 ↗
3. Dynamic forces over the interface between a seated human body and a rigid seat during vertical whole-body vibration10.1016/j.jbiomech.2017.07.015 ↗
4. Fore-and-aft and dual-axis vibration of the seated human body: Nonlinearity, cross-axis coupling, and associations between resonances in the transmissibility and apparent mass10.1016/j.ergon.2018.08.007 ↗
5. The apparent mass of the seated human body in the fore-and-aft and lateral directions10.1016/0022-460X(90)90890-C ↗
6. Tri-axial forces at the seat and backrest during whole-body fore-and-aft vibration10.1016/j.jsv.2004.02.047 ↗
7. Nonlinearity in the vertical transmissibility of seating: The role of the human body apparent mass and seat dynamic stiffness10.1080/00423114.2012.715652 ↗
8. Non-linearities in apparent mass and transmissibility during exposure to whole-body vertical vibration10.1016/S0021-9290(00)00052-X ↗
9. Non-linear characteristics in the dynamic responses of seated subjects exposed to vertical whole-body vibration10.1115/1.1499959 ↗
10. Biodynamic responses of the seated human body to single-axis and dual-axis vibration10.2486/indhealth.MSWBVI-26 ↗
11. Nonlinearity in apparent mass and transmissibility of the supine human body during vertical whole-body vibration10.1016/j.jsv.2009.02.017 ↗
12. Sitting comfort in vibration environment: Inter-axis equivalence and equivalent comfort contours for fore-aft, lateral, vertical, and pitch motion
13. Effects of Posture and Vibration Magnitude on Apparent Mass and Pelvis Rotation during Exposure to Whole-Body Vertical Vibration10.1006/jsvi.2001.4251 ↗
14. An analytic model of the in-line and cross-axis apparent mass of the seated human body exposed to vertical vibration with and without a backrest10.1016/j.jsv.2011.06.026 ↗
15. Biodynamic response of the seated human body to single-axis and dual-axis vibration: Effect of backrest and non-linearity10.2486/indhealth.MS1298 ↗
16. Transmission of vertical vibration through a seat: Effect of thickness of foam cushions at the seat pan and the backrest10.1016/j.ergon.2015.03.006 ↗
17. Apparent mass of the human body in the vertical direction: Effect of a footrest and a steering wheel10.1016/j.jsv.2009.11.015 ↗
18. The transmission of vertical vibration through seats: Influence of the characteristics of the human body10.1016/j.jsv.2011.07.033 ↗
19. Effects of sitting postures on biodynamic response of seated occupants under vertical vibration10.1016/j.ergon.2004.04.009 ↗
20. Mechanism associated with the effect of backrest inclination on biodynamic responses of the human body sitting on a rigid seat exposed to vertical vibration10.1016/j.jsv.2021.116299 ↗
21. Fore-and-aft transmissibility of backrests: Effect of backrest inclination, seat-pan inclination, and measurement location10.1016/j.jsv.2006.06.053 ↗
22. Sitting comfort and discomfort and the relationships with objective measures10.1080/0014013031000121977 ↗
23. Lumbar disc pressure and myoelectric back muscle activity during sitting. IV. Studies on a car driver’s seat10.2340/1650197761128133 ↗
24. Effect of the seating condition on the transmission of vibration through the seat pan and backrest10.1016/j.ergon.2014.12.005 ↗
25. Whole-body vibration exposure in unfavourable seated postures: Apparent mass and seat-to-head transmissibility measurements in the fore-and-aft, lateral, and vertical directions10.1080/00140139.2022.2063950 ↗
26. Mănescu, A.M., and Mănescu, D.C. (2025). Self-Supervised Gait Event Detection from Smartphone IMUs for Human Performance and Sports Medicine. Appl. Sci., 15.10.3390/app152211974 ↗
27. Modelling the fore-and-aft apparent mass of the human body and the transmissibility of seat backrests10.1080/00423111003695594 ↗
28. Vibration reduction of human body biodynamic response in sitting posture under vibration environment by seat backrest support10.1038/s41598-024-56109-y ↗
29. Effect of sitting posture and seat on biodynamic responses of internal human body simulated by finite element modeling of body-seat system10.1016/j.jsv.2018.09.012 ↗
30. Finite element modelling and biodynamic response prediction of the seated human body exposed to whole-body vibration10.1080/00140139.2023.2168064 ↗
31. Subjective discomfort caused by vertical whole-body vibration in the frequency range 2–100 Hz10.1080/00140139.2018.1533145 ↗
32. Equivalent magnitude-dependent discomfort under vertical vibration up to 100 Hz10.1080/00140139.2022.2152108 ↗
33. (1997). Mechanical Vibration and Shock Evaluation of Human Exposure to Whole-Body Vibration—Part 1: General Requirements (Standard No. ISO 2631-1:1997).
34. Discomfort during lateral acceleration: Influence of seat cushion and backrest10.1016/j.apergo.2012.11.009 ↗
35. Discomfort of seated persons exposed to low frequency lateral and roll oscillation: Effect of backrest height10.1016/j.apergo.2015.11.010 ↗
36. Predicting discomfort from whole-body vertical vibration when sitting with an inclined backrest10.1016/j.apergo.2012.10.006 ↗
37. Equivalent comfort contours for vertical seat vibration: Effect of vibration magnitude and backrest inclination10.1080/00140139.2012.678390 ↗
38. The vibration of inclined backrests: Perception and discomfort of vibration applied parallel to the back in the z-axis of the body10.1080/00140139.2011.624200 ↗
39. The vibration of inclined backrests: Perception and discomfort of vibration applied normal to the back in the x-axis of the body10.1016/j.jsv.2011.04.021 ↗
40. (1995). Volume I—Man-Systems Integration Standards (Standard No. NASA-STD-3000).
41. (2015). Devices for Use in Defining and Measuring Vehicle Seating Accommodation (Standard No. SAE J826-2015).
42. A literature review on optimum and preferred joint angles in automotive sitting posture10.1016/j.apergo.2013.04.009 ↗
43. Specifying comfortable driving postures for ergonomic design and evaluation of the driver workspace using digital human models10.1080/00140130902763552 ↗
44. Biodynamic response of seated human body to roll vibration: Effect of armrest support10.1016/j.jsv.2022.116939 ↗
45. Issues in psychophysical measurement10.1037/h0031324 ↗
46. Li, J., Zhao, Y., Zheng, H., and Guo, R. (2025). Vehicle vibration modelling via road profile reconstruction and simulation: Coupled analysis of IRI, speed, and ride comfort for driving assistance. Road. Mater. Pavement Des., 1–26.10.1080/14680629.2025.2574300 ↗
47. Ride comfort assessment for automated vehicles utilizing a road surface model and Monte Carlo simulations10.1111/mice.12787 ↗
48. Payton, C.J., and Bartlett, R. (2007). Biomechanical Evaluation of Movement in Sport and Exercise, Routledge.10.4324/9780203935750 ↗