Risk factors for ‘whiplash’ in drivers: a cohort study of rear-end traffic crashes

doi:10.1016/S0020-1383(96)00186-6

Injury

Volume 28, Issue 3, April 1997, Pages 173-179

https://doi.org/10.1016/S0020-1383(96)00186-6 Get rights and content

Abstract

‘Whiplash’ injuries are a common cause of road traffic accident (RTA) related morbidity. However, few epidemiological studies have investigated risk factors associated with the occurrence of such injuries. The purpose of this study was to examine relationships between vehicle and occupant factors and the incidence of ‘whiplash’ in drivers with recent experience of a rear-end impact in an RTA. A cohort of 246 car drivers with recent experience of a rear-end impact in the Adelaide metropolitan area was recruited. Structured telephone interviews were used to obtain information about driver demographics, the circumstances of the crash, and injuries resulting from the crash. Two factors were identified as independent risk factors for ‘whiplash’ injury: a history of neck injury (adjusted odds ratio = 4.50, 95 per cent confidence interval 1.97–10.28) and female sex (adjusted odds ratio = 2.08, 95 per cent confidence interval 1.13–3.82). The relative weight of the striking vehicle to the driver's vehicle was also positively associated with risk of ‘whiplash’ injury. There was no evidence that the driver's occupation or level of education are predictors of occurrence. Methodological aspects of the study which might have resulted in bias are discussed and suggestions are given for overcoming these in future work.

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Sex and posture dependence of neck muscle size-strength relationships
2021, Journal of Biomechanics
Citation Excerpt :
Prior investigations of size-strength relationships lumped a single regression model without separating males and females in spite of the bimodal distributions of both strength and size (Holzbaur et al., 2007a). Such an approach inflates the correlation strength and does not allow for sex-specific analyses and insights, while sex differences have been reported not only in neck pain incidence but also in neck impact injury risk, persistency, and treatment outcome (Berglund et al., 2006; Côté et al., 2004; Dolinis, 1997; Guez et al., 2002; Hendriks et al., 2005; Hoy et al., 2010). Motivated by the belief that prolonged deviated neck posture is a risk factor for neck pain and the fact that prior injury prediction studies had only evaluated neck strength in a neutral posture, recent investigations have studied neck strength in different directions and non-neutral positions (Ariëns et al., 2001; Cagnie et al., 2007b; Gilchrist et al., 2016; Hildenbrand and Vasavada, 2013; Salo et al., 2006).
Neck muscle size and strength have been linked to lower injury risk and reduced pain. However, prior findings have been inconclusive and have failed to clarify whether there are sex differences in neck muscle size-strength relationships. Such differences may point to an underlying cause for the reported sex difference in neck pain prevalence. Thirty participants (13 males, 17 females) who underwent neck strength testing and MR imaging were analyzed. Strength was measured in three conditions that differed in posture and exertion direction. Muscle size was quantified by three metrics: anatomical cross-sectional area (ACSA), muscle volume (MV), and an estimate of physiological cross-sectional area—reconstruction-based cross-sectional area (RCSA). Inter-posture strength correlations, muscle size-strength correlations, and sex differences were analyzed with linear regression. Males were approximately 65% stronger and had significantly larger muscles. Strength varied significantly across postures, but only female strength values for different postures were significantly correlated. Observed in males only, the sternocleidomastoid (SCM) was a strong predictor of flexion strength in the neutral posture while the anterior scalene (AS) was more involved in the extended. No extensor’s size was significantly linked to extension strength. A greater amount of force variation is unexplained by muscle size alone in females than in males. Males and females exhibited distinct size-strength relationships, highlighting the need for sex-specific models and analyses and the greater potential effect of non-morphometric factors on force generating capacity in females. No advantage of one muscle size metric over another in strength prediction was evidenced.
Review of average sized male and female occupant models in European regulatory safety assessment tests and European laws: Gaps and bridging suggestions
2019, Accident Analysis and Prevention
There are two parts to the aim of this study. The first part comprised reviewing how men and women are represented in regulatory tests conducted to assess adult occupant safety in vehicles in Europe. This part also contains an overview of some differences between females and males that may influence dynamic responses in a crash. Based on the results of the review an outline for how to better represent the adult population in regulatory tests has been suggested.
The second part was to reflect on these issues from a specific critical legal perspective, that is from a Gender Legal Studies point of view, focusing on the European legal framework that governs the tests of adult occupant safety in vehicles in Europe. Since the beginning of the 1970s legal scholars have shown in several areas of law that there is a gap between superior legislation and practice, but also between gender equality as a superior legal principle and subordinate legal rules that govern safety requirements. The same pattern can be discerned in the area of Transportation Law.
The results of the review of the ECE regulations shows that the average sized male represents the adult population and that the average sized female has been excluded from regulations assessing the protection of adult vehicle occupants. The fundamental values, on which the Union is founded, including the overarching goals of the Union, seem to be rendered invisible in the laws and critically impact the safety of women in everyday life. According to the gender system theory, the interests and priorities of men are continuing to shape the law. Consequently, the law neglecting the safety of women on roads has implications on the development of society. The lack of legal provisions that demand female crash test dummies representing the female part of the population, means that there is no incentive for car manufacturers, authorities or other stakeholders to develop test methods and female crash test dummies in ways that promote political objectives expressed in legal form, i.e., the legal values expressed in general provisions and principles stated in the Treaty on European Union and the Treaty on the Functioning of the European Union, such as gender equality between women and men as well as non-discrimination
This study highlights the undeniable gap between the legal framework and legal requirements with regard to occupant safety for the whole adult population. It would be attainable to bridge this particular gender gap by providing equal representation for the female part of the population with regard to vehicle safety, as that males benefit from.
Average male and female virtual dummy model (BioRID and EvaRID) simulations with two seat concepts in the Euro NCAP low severity rear impact test configuration
2018, Accident Analysis and Prevention
Soft tissue neck injuries, also referred to as whiplash injuries, which can lead to long term suffering accounts for more than 60% of the cost of all injuries leading to permanent medical impairment for the insurance companies, with respect to injuries sustained in vehicle crashes. These injuries are sustained in all impact directions, however they are most common in rear impacts. Injury statistics have since the mid-1960s consistently shown that females are subject to a higher risk of sustaining this type of injury than males, on average twice the risk of injury. Furthermore, some recently developed anti-whiplash systems have revealed they provide less protection for females than males. The protection of both males and females should be addresses equally when designing and evaluating vehicle safety systems to ensure maximum safety for everyone. This is currently not the case. The norm for crash test dummies representing humans in crash test laboratories is an average male. The female part of the population is not represented in tests performed by consumer information organisations such as NCAP or in regulatory tests due to the absence of a physical dummy representing an average female.
Recently, the world first virtual model of an average female crash test dummy was developed. In this study, simulations were run with both this model and an average male dummy model, seated in a simplified model of a vehicle seat. The results of the simulations were compared to earlier published results from simulations run in the same test set-up with a vehicle concepts seat. The three crash pulse severities of the Euro NCAP low severity rear impact test were applied. The motion of the neck, head and upper torso were analysed in addition to the accelerations and the Neck Injury Criterion (NIC). Furthermore, the response of the virtual models was compared to the response of volunteers as well as the average male model, to that of the response of a physical dummy model. Simulations with the virtual male and female dummy models revealed differences in dynamic response related to the crash severity, as well as between the two dummies in the two different seat models. For the comparison of the response of the virtual models to the response of the volunteers and the physical dummy model, the peak angular motion of the first thoracic vertebra as found in the volunteer tests and mimicked by the physical dummy were not of the same magnitude in the virtual models.
The results of the study highlight the need for an extended test matrix that includes an average female dummy model to evaluate the level of occupant protection different seats provide in vehicle crashes. This would provide developers with an additional tool to ensure that both male and female occupants receive satisfactory protection and promote seat concepts that provide the best possible protection for the whole adult population. This study shows that using the mathematical models available today can provide insights suitable for future testing.
The risk of whiplash-induced medical impairment in rear-end impacts for males and females in driver seat compared to front passenger seat
2013, IATSS Research
Citation Excerpt :
This finding is similar to the results achieved by Krafft et al. [9] using the same methodology as in this study, that described by Evans [21] (see Material and methods section). Dolinis [4] also found an increased RR for females; twice that of males, in this case. There are several possible explanations for this phenomenon.
The objective of this study was to study whiplash injury outcome in front-seat occupants in rear-end impacts using double paired comparison technique. The combination of gender, seated position, and outcome was analyzed. Folksam, a Swedish insurance company, has a database of whiplash injuries. A questionnaire was used to collect study data. The response rate was 81%. The inclusion criteria included medical impairment one year after the impact, as judged by medical specialists. The study included rear-end impacts between 1990 and 1999 that resulted in at least one permanent neck injury impairment; in total, 430 impacts with 860 occupants and 444 impairments. Of those suffering impairment, 302 were female and 142 male; 235 were seated in the driver's seat and 209 in the front passenger seat. Relative risk estimates for impairing whiplash injury, by gender and seated position:
- 1.
  Driver male (DM)/passenger female (PF) relative risk = 0.5 n = 218
- 2.
  Driver male (DM)/passenger male (PM) relative risk = 1.4 n = 57
- 3.
  Driver female (DF)/passenger female (PF) relative risk = 2.5 n = 102
- 4.
  Driver female (DF)/passenger male (PM) relative risk = 4.6 n = 67.
Females had a relative risk of medical impairment of 3.1 compared to men after adjustment for the average increased risk in the driver position. The driver position had a doubled relative risk compared to the front passenger position. As a conclusion it may be of value to take risk differences between male and female occupants and between driver and front passenger positions into account in future automotive car and seat construction.
The role of fear of movement in subacute whiplash-associated disorders grades i and II
2013, Pain
Fear and avoidance of activity may play a role in fostering disability in whiplash-associated disorders (WAD). This study examined the role of fear after WAD and assessed the effectiveness of 3 treatments targeting fear. People still symptomatic from WAD grade I-II injuries approximately 3 months previously (n = 191) completed questionnaires (eg, Neck Disability Index [NDI]) and were randomized to 1 of the treatments: (1) informational booklet (IB) describing WAD and the importance of resuming activities, (2) IB + didactic discussions (DD) with clinicians reinforcing the booklet, and (3) IB + imaginal and direct exposure desensitization (ET) to feared activities. DD and ET participants received three 2-hour treatment sessions. Absolute improvements in NDI were in predicted direction (ET = 14.7, DD = 11.9, IB = 9.9). ETs reported significantly less posttreatment pain severity compared with the IB (Mean = 1.5 vs 2.3, P < .001, d = 0.6) and DD (M = 1.5 vs 2.0, P = .039, d = 0.6) groups. Reduction in fear was the most important predictor of improvement in NDI (β = 0.30, P < .001), followed by reductions in pain (β = 0.20, P = .003) and depression (β = 0.18, P = .004). The mediational analysis confirmed that fear reduction significantly mediated the effect of treatment group on outcome. Results highlight the importance of fear in individuals with subacute WAD and suggest the importance of addressing fear via exposure therapy and/or educational interventions to improve function.
ADSEAT - Adaptive seat to reduce neck injuries for female and male occupants
2013, Accident Analysis and Prevention
Citation Excerpt :
Whiplash injuries occur at relatively low velocity changes (typically <25 km/h) (Eichberger et al., 1996; Kullgren et al., 2003), and in impacts from all directions, although rear impacts are most frequently featured in accident statistics (Watanabe et al., 2000). Injury statistics from the mid 1960s until today show that females have a higher risk of sustaining whiplash injuries than males, ranging from 1.5 to 3 times higher (Kihlberg, 1969; O’Neill et al., 1972; Thomas et al., 1982; Otremski et al., 1989; Maag et al., 1990; Morris and Thomas, 1996; Dolinis, 1997; Temming and Zobel, 1998; Richter et al., 2000; Chapline et al., 2000; Krafft et al., 2003; Jakobsson et al., 2004; Storvik et al., 2009). In general, concepts for whiplash protection seats have proved to be more effective for males than females (Kullgren and Krafft, 2010).
Neck injuries sustained in low severity vehicle crashes are of worldwide concern and the risk is higher for females than for males. The objective of the study was to provide guidance on how to evaluate protective performance of vehicle seat designs aiming to reduce the incidence of neck injuries for female and male occupants. The objective was achieved by reviewing injury risk, establishing anthropometric data of an average female, performing dynamic volunteer tests comprising females and males, and developing a finite element model, EvaRID, of an average female. With respect to injury criteria, it was concluded based on the tests that using NIC (with a lower threshold value) and Nkm (with reduced intercept values) for females would be a suitable starting point. Virtual impact simulations with seats showed that differences were found in the response of the BioRID II and EvaRID models, for certain seats.

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PaperRisk factors for ‘whiplash’ in drivers: a cohort study of rear-end traffic crashes

Abstract

Injury

Injury

Injury

Accid Anal Prev

The clinical picture of whiplash injuries: an overview

Spine State Art Rev

The pathophysiology of whiplash

Spine State Art Rev

Neck sprains in car crashes: incidence, associations, length of compensation and costs to the insurer

Paper
Risk factors for ‘whiplash’ in drivers: a cohort study of rear-end traffic crashes