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Subjects. (A) Anterior view of subjects sitting in driver and FSP position. Infrared-reflective markers were attached at anatomical landmarks. The LED-flash (at the middle-top of the figure) was triggered when the pendulum hit the bumper. The steering wheel was trimmed to provide a better view for the motion capture cameras. (B) Posterior (C) and lateral view of the subjects. The EMG electrodes were placed at the sternocleidomastoid, trapezius, and paraspinal muscles. https://doi.org/10.1371/journal.pone.0209753.g002
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Background
Low-velocity motor vehicle crashes often lead to severe and chronic neck disorders also referred to as whiplash-associated disorders (WAD). The etiology of WAD is still not fully understood. Many studies using a real or simulated collision scenario have focused on rear-end collisions, whereas the kinematics and muscular responses during...
Contexts in source publication
Context 1
... electrode placement was done according to Hermens et al. (1999) [39] and Falla et al. (2002) [40]. For the SCM, the electrodes were attached along the sternal portion of the muscle, with the electrode center at 1/3 of the distance between the sternal notch and the mastoid process [40] (Fig 2C). For the TRA, the electrodes were positioned halfway between Table 1. ...
Context 2
... subject A subject B 3 tense 2 subject A subject B 6 tense 3-6 subject A subject B 3 or 6 tense or relaxed 7-10 subject B subject A 3 or 6 tense or relaxed https://doi.org/10.1371/journal.pone.0209753.t001 the 7th cervical vertebra (C7) and acromion while the PARA-electrodes were located laterally to the spinal column directly under the hairline (Fig 2B). The common ground electrode was affixed at C7. Tape was used to secure the electrodes. ...
Context 3
... markers were attached to the head, breast, shoulders, upper arms and forearms (Fig 2A). Except for the shoulder markers, all subject markers were grouped in clusters of three or four so that the 3D orientation of the body segment could be computed in addition to the 3D position. ...
Context 4
... for the influence of the belt, the orientation of the customary 3-point lap and shoulder belt is different in the driver and FSP position (Fig 2A). While in frontal, rear-end, and lateral collision directions the influence of the shoulder belt's asymmetry is expected to be minor, oblique impact directions may interact with an asymmetrical shoulder belt orientation in an exacerbating manner, and this interaction may affect the driver and the FSP differently. ...
Similar publications
Numerical human body models that can predict occupant head and neck responses are essential for the development and assessment of motor vehicle safety systems. Including the contribution of neck muscle responses is needed to improve model predictions, in particular during simulated pre-crash manoeuvers. While a general purpose model that can predic...
Citations
... Injuries to the larynx, trachea, cricoid, or supporting structures carry substantial early mortality, approaching 35% in some reports, due to the threats of asphyxiation and hemorrhage [5,6]. Blunt mechanisms such as motor vehicle collisions, clothesline injuries, and penetrating neck trauma contribute to airway compromise syndromes [7][8][9][10]. ...
Background: Laryngotracheal trauma is associated with a substantial risk of mortality. Age can be a critical factor in trauma management, as older adults often have diminished airway protective reflexes and preexisting respiratory conditions. Objective: This study aimed to characterize the clinical profiles and outcomes in different age groups of adult patients with laryngotracheal trauma using data from the National Trauma Data Bank (NTDB). Methods: We retrospectively analyzed the NTDB and included adult patients (aged ≥ 18 years) who had laryngotracheal fractures (closed or open) and were admitted directly after the injury. The patients were categorized into different age groups for analysis. A multivariate logistic regression analysis was performed to assess whether the elderly population (age ≥ 65 years) was predisposed to post-trauma death under care. Results: The study included 1171 patients, with the following age distributions: 13.7% aged 18–24 years, 21.6% aged 25–34 years, 55.2% aged 35–64 years, and 9.6% aged ≥ 65 years. Notable differences were observed in comorbidities, mechanisms, types of injuries, and associated injuries among age groups. There was no significant trend in airway surgical outcomes according to age. In-hospital mortality was highest among patients aged ≥ 65 years (22.3%), compared to 14.4% for those aged 18–24 years. Regression analysis indicated that age ≥ 65 was an independent mortality predictor. Conclusions: These findings underscore significant age-related differences in the presentation and outcomes of laryngotracheal trauma, emphasizing the need for age-specific treatment protocols, primarily to address the elevated risk among elderly patients.
... Based on 1001 individual medical examinations performed at the OFI Orthopädisches Forschungsinstitut Münster, we found that most of the WAD cases occur subsequent to rear-end collisions (56%). Interestingly, frontal-oblique collisions (16.7%) induced WAD more often than purely frontal (7.4%) or lateral collisions (7.7%, non-published data, see Mühlbeier et al. (2018)). Hence, it appears relevant to investigate frontaloblique impact directions, which typically occur during intersection accidents and sliding collisions. ...
... Therefore, we conducted an extensive study with 60 voluntary subjects exposed to low-velocity left-frontaloblique impacts, to gain further insights into the neuromuscular mechanisms underlying whiplash-like perturbations that may cause the sex differences in the prevalence of WAD. In a within-subject study design, we varied several impact parameters to investigate their effect on the neck muscle response amplitude and delay, i.e. impact velocity difference ∆v (3 / 6 km/h), seating position (driver / front seat passenger), and deliberate pre-tension of the musculature (tense / relaxed) (Mühlbeier et al., 2018). In a between-subject design, we analyzed possible sex differences in the kinematic responses as well as in the neck muscle responses. ...
... The following methods description is partially adopted from Mühlbeier et al. (2018), as both studies are part of a bigger research project. ...
Low-velocity motor vehicle crashes frequently induce chronic neck disorders also referred to as whiplash-associated disorders (WAD). The etiology of WAD is still not fully understood. Women are affected more often and more severely than men. A frontal-oblique collision direction leads to WAD relatively frequently, but is poorly investigated as compared to rear-end or frontal collision directions. An oblique impact direction is assumed to strain the contralateral neck side more than the ipsilateral side, provoking an asymmetrical response pattern of the left and right cervical muscles. In this study, we examined the muscle reflex responses of the sternocleidomastoid, the paraspinal, and the trapezius muscles as well as the kinematic responses of 60 subjects during left-frontal-oblique collisions. Neither the reflex delay nor the peak head acceleration revealed significant sex differences. Thus, the elsewhere reported higher injury risk of females as compared to males cannot be explained by the electromyographic and kinematic results of this study. In females as well as in males the right muscle responses revealed shorter onset times than the left muscle responses. Thus, cervical muscles seem to be activated depending on the specific direction of the impact. Moreover, the difference between right and left muscle responses cannot be explained by a startle reflex. The movement of the head in relation to the torso (female mean ± SD: 92 ± 16 ms; male: 87 ± 16 ms) started almost simultaneously to the onset of the first muscle activation (right paraspinal muscles: female mean: 95 ms and 95%-CI 82 − 109; male mean: 95 ms and 95%-CI 84 − 108) indicating that the initial muscle activity seems not to be triggered by a stretch reflex in the PARA muscles.
Instinctive response was produced for protecting drivers from injury when facing incoming collisions. For better understanding it’s influence of lower extremity injury, this study proposed an approach to analyze the collision injury considering the instinctive response posture and musculoskeletal characteristics. 20 male drivers were recruited for an instinctive response test in driving simulator and their lower extremity postures and muscle activation of 8 major ones at the collision moment were collected. The difference between different postures and muscles were analyzed and their influence on injuries were investigated by collision simulation. Results showed that increased possibility for the right leg holding on the air or even on the accelerator pedal with increased emergency level at the collision moment. Significant difference existed in different muscles between different postures. The introduction of instinctive response changed the driving posture and musculoskeletal characteristics, which further influence the lower extremity injury. This study help understanding the accurate behavioral and injury procedure and providing support for design a better restraint systems.
Occupants exposed to low or moderate crash events can already suffer from whiplash-associated disorders leading to severe and long-lasting symptoms. However, the underlying injury mechanisms and the role of muscle activity are not fully clear. Potential increases in injury risk of non-nominal postures, i.e., rotated head, cannot be evaluated in detail due to the lack of experimental data. Examining changes in neck muscle activity to hold and stabilize the head in a rotated position during pre-crash scenarios might provide a deeper understanding of muscle reflex contributions and injury mechanisms. In this study, the influence of two different head postures (nominal vs. rotation of the head by about 63 ± 9° to the right) on neck muscle activity and head kinematics was investigated in simulated braking experiments inside a driving simulator. The braking scenario was implemented by visualization of the virtual scene using head-mounted displays and a combined translational-rotational platform motion. Kinematics of seventeen healthy subjects was tracked using 3D motion capturing. Surface electromyography were used to quantify muscle activity of left and right sternocleidomastoideus (SCM) and trapezius (TRP) muscles. The results show clear evidence that rotated head postures affect the static as well as the dynamic behavior of muscle activity during the virtual braking event. With head turned to the right, the contralateral left muscles yielded higher base activation and delayed muscle onset times. In contrast, right muscles had much lower activations and showed no relevant changes in muscle activation between nominal and rotated head position. The observed delayed muscle onset times and increased asymmetrical muscle activation patterns in the rotated head position are assumed to affect injury mechanisms. This could explain the prevalence of rotated head postures during a crash reported by patients suffering from WAD. The results can be used for validating the active behavior of human body models in braking simulations with nominal and rotated head postures, and to gain a deeper understanding of neck injury mechanisms.
Mild traumatic brain injury (mTBI) and whiplash-associated disorder are the most common head and neck injuries and result from a sudden head or body acceleration. The head and neck injury potential is correlated with the awareness, level of muscle activation, and posture changes at the time of the perturbation. Environmental acoustic stimuli or a warning system can influence muscle activation and posture during a head perturbation. In this study, different acoustic stimuli, including Non-Directional, Directional, and Startle, were provided 1000 ms before a head impact, and the amplitude and timing of cervical muscle electromyographic (EMG) data were characterized based on the type of warning. The startle warning resulted in 49% faster and 80% greater EMG amplitude compared to the Directional and Non-Directional warnings after warning and before the impact. The post-impact peak EMG amplitudes in Unwarned trials were lower by 18 and 21% in the retraction and rebound muscle groups, respectively, compared to any of the warned conditions. When there was no warning before the impact, the retraction and rebound muscle groups also reached their maximum activation 38 and 54 ms sooner, respectively, compared to the warned trials. Based on these results, the intensity and complexity of information that a warning sound carries change the muscle response before and after a head impact and has implications for injury potential.
