Société de Biomécanique Young Investigator Award 2019: Upper body behaviour of seated humans in vivo under controlled lateral accelerations.
Head
Kinematics
Lateral bending
Neck
Sled
Stabilization strategies
Volunteer experiments
Journal
Clinical biomechanics (Bristol, Avon)
ISSN: 1879-1271
Titre abrégé: Clin Biomech (Bristol, Avon)
Pays: England
ID NLM: 8611877
Informations de publication
Date de publication:
05 2023
05 2023
Historique:
received:
18
11
2022
revised:
21
02
2023
accepted:
04
04
2023
medline:
22
5
2023
pubmed:
16
5
2023
entrez:
15
5
2023
Statut:
ppublish
Résumé
A deep understanding of human reactions and stabilization strategies is required to predict their kinematics under external dynamic loadings, such as those that occur in vehicle passengers. Low-level frontal accelerations have been thoroughly investigated; however, the human response to different lateral accelerations is not well understood. The objective of this study is to gain insight regarding the responses of seated humans to lateral perturbations from volunteer experiments in different configurations. Five volunteers anthropometrically comparable to the 50th-percentile American male, were seated on a sled and submitted to 21 lateral pulses. Seven configurations, each repeated three times, were investigated in this study: a relaxed muscular condition with four pulses, namely, sine and plateau pulses of 0.1 and 0.3 g in a straight spinal posture; a relaxed muscular condition with a plateau pulse of 0.3 g in a sagging spinal posture; and a braced condition with both plateau pulses in a straight spinal posture. Upper body segment kinematics were assessed using inertial measurement units. The maximum lateral bending of the head was found to differ significantly among the four acceleration pulses (p < 0.001). Braced muscles significantly reduced lateral bending compared to relaxed muscles (p < 0.001). However, no significant difference was found in lateral bending between straight and sagging spinal postures (p = 0.23). The study shows that not only pulse amplitude but also pulse shape influences human responses to low accelerations, while spinal posture does not influence lateral head bending. These data can be used to evaluate numerical active human body models.
Sections du résumé
BACKGROUND
A deep understanding of human reactions and stabilization strategies is required to predict their kinematics under external dynamic loadings, such as those that occur in vehicle passengers. Low-level frontal accelerations have been thoroughly investigated; however, the human response to different lateral accelerations is not well understood. The objective of this study is to gain insight regarding the responses of seated humans to lateral perturbations from volunteer experiments in different configurations.
METHODS
Five volunteers anthropometrically comparable to the 50th-percentile American male, were seated on a sled and submitted to 21 lateral pulses. Seven configurations, each repeated three times, were investigated in this study: a relaxed muscular condition with four pulses, namely, sine and plateau pulses of 0.1 and 0.3 g in a straight spinal posture; a relaxed muscular condition with a plateau pulse of 0.3 g in a sagging spinal posture; and a braced condition with both plateau pulses in a straight spinal posture. Upper body segment kinematics were assessed using inertial measurement units.
FINDINGS
The maximum lateral bending of the head was found to differ significantly among the four acceleration pulses (p < 0.001). Braced muscles significantly reduced lateral bending compared to relaxed muscles (p < 0.001). However, no significant difference was found in lateral bending between straight and sagging spinal postures (p = 0.23).
INTERPRETATION
The study shows that not only pulse amplitude but also pulse shape influences human responses to low accelerations, while spinal posture does not influence lateral head bending. These data can be used to evaluate numerical active human body models.
Identifiants
pubmed: 37187012
pii: S0268-0033(23)00083-9
doi: 10.1016/j.clinbiomech.2023.105952
pii:
doi:
Types de publication
Journal Article
Research Support, Non-U.S. Gov't
Langues
eng
Sous-ensembles de citation
IM
Pagination
105952Informations de copyright
Copyright © 2023 Elsevier Ltd. All rights reserved.
Déclaration de conflit d'intérêts
Declaration of Competing Interest No competing financial interests exist.