Are there gender differences in coping with neck pain following acute whiplash trauma? A 12-month follow-up study: Are there gender differences in coping with neck pain following acute whiplash trauma?

Biomechanics of Traumatic Head and Neck Injuries on Women: A State-of-the-Art Review and Future Directions

The biomechanics of traumatic injuries of the human body as a consequence of road crashes, falling, contact sports, and military environments have been studied for decades. In particular, traumatic brain injury (TBI), the so-called "silent epidemic", is the traumatic insult responsible for the greatest percentage of death and disability, justifying the relevance of this research topic. Despite its great importance, only recently have research groups started to seriously consider the sex differences regarding the morphology and physiology of women, which differs from men and may result in a specific outcome for a given traumatic event. This work aims to provide a summary of the contributions given in this field so far, from clinical reports to numerical models, covering not only the direct injuries from inertial loading scenarios but also the role sex plays in the conditions that precede an accident, and post-traumatic events, with an emphasis on neuroendocrine dysfunctions and chronic traumatic encephalopathy. A review on finite element head models and finite element neck models for the study of specific traumatic events is also performed, discussing whether sex was a factor in validating them. Based on the information collected, improvement perspectives and future directions are discussed.

The Effect of Seat Back Inclination on Spinal Alignment in Automotive Seating Postures

Experimental studies have demonstrated a relationship between spinal injury severity and vertebral kinematics, influenced by the initial spinal alignment of automotive occupants. Spinal alignment has been considered one of the possible causes of gender differences in the risk of sustaining spinal injuries. To predict vertebral kinematics and investigate spinal injury mechanisms, including gender-related mechanisms, under different seat back inclinations, it is needed to investigate the effect of the seat back inclination on initial spinal alignment in automotive seating postures for both men and women. The purpose of this study was to investigate the effect of the seat back inclination on spinal alignments, comparing spinal alignments of automotive seating postures in the 20° and 25° seat back angle and standing and supine postures. The spinal columns of 11 female and 12 male volunteers in automotive seating, standing, and supine postures were scanned in an upright open magnetic resonance imaging system. Patterns of their spinal alignments were analyzed using Multidimensional Scaling presented in a distribution map. Spinal segmental angles (cervical curvature, T1 slope, total thoracic kyphosis, upper thoracic kyphosis, lower thoracic kyphosis, lumbar lordosis, and sacral slope) were also measured using the imaging data. In the maximum individual variances in spinal alignment, a relationship between the cervical and thoracic spinal alignment was found in multidimensional scaling analyses. Subjects with a more lordotic cervical spine had a pronounced kyphotic thoracic spine, whereas subjects with a straighter to kyphotic cervical spine had a less kyphotic thoracic spine. When categorizing spinal alignments into two groups based on the spinal segmental angle of cervical curvature, spinal alignments with a lordotic cervical spine showed significantly greater absolute average values of T1 slope, total thoracic kyphosis, and lower thoracic kyphosis for both the 20° and 25° seat back angles. For automotive seating postures, the gender difference in spinal alignment was almost straight cervical and less-kyphotic thoracic spine for the female subjects and lordotic cervical and more pronounced kyphotic thoracic spine for the male subjects. The most prominent influence of seatback inclination appeared in Total thoracic kyphosis, with increased angles for 25° seat back, 8.0° greater in spinal alignments with a lordotic cervical spine, 3.2° greater in spinal alignments with a kyphotic cervical spine. The difference in total thoracic kyphosis between the two seatback angles and between the seating posture with the 20° seat back angle and the standing posture was greater for spinal alignments with a lordotic cervical spine than for spinal alignments with a kyphotic cervical spine. The female subjects in this study had a tendency toward the kyphotic cervical spine. Some of the differences between average gender-specific spinal alignments may be explained by the findings observed in the differences between spinal alignments with a lordotic and kyphotic cervical spine.

Dynamic Responses of Female Volunteers in Rear Impact Sled Tests at Two Head Restraint Distances

The objective of this study was to assess the biomechanical and kinematic responses of female volunteers with two different head restraint (HR) configurations when exposed to a low-speed rear loading environment. A series of rear impact sled tests comprising eight belted, near 50th percentile female volunteers, seated on a simplified laboratory seat, was performed with a mean sled acceleration of 2.1 g and a velocity change of 6.8 km/h. Each volunteer underwent two tests; the first test configuration, HR10, was performed at the initial HR distance ∼10 cm and the second test configuration, HR15, was performed at ∼15 cm. Time histories, peak values and their timing were derived from accelerometer data and video analysis, and response corridors were also generated. The results were separated into three different categories, HR10_C (N = 8), HR15_C (N = 6), and HR15_NC (N = 2), based on: (1) the targeted initial HR distance [10 cm or 15 cm] and (2) whether the volunteers’ head had made contact with the HR [Contact (C) or No Contact (NC)] during the test event. The results in the three categories deviated significantly. The greatest differences were found for the average peak head angular displacements, ranging from 10° to 64°. Furthermore, the average neck injury criteria (NIC) value was 22% lower in HR10_C (3.9 m²/s²), and 49% greater in HR15_NC (7.4 m²/s²) in comparison to HR15_C (5.0 m²/s²). This study supplies new data suitable for validation of mechanical or mathematical models of a 50th percentile female. A model of a 50th percentile female remains to be developed and is urgently required to complement the average male models to enhance equality in safety assessments. Hence, it is important that future protection systems are developed and evaluated with female properties taken into consideration too. It is likely that the HR15 test configuration is close to the limit for avoiding HR contact for this specific seat setup. Using both datasets (HR15_C and HR15_NC), each with its corresponding HR contact condition, will be possible in future dummy or model evaluation.

Management of Lemierre syndrome

Lemierre syndrome is a rare form of septic thrombophlebitis of the head and neck veins, most typically the internal jugular vein, which affects otherwise healthy adolescents and young adults after an oropharyngitis or other local infection and is characterized by multiple septic embolization. Despite treatment, Lemierre syndrome displays a high rate of in-hospital complications that include thrombus progression and new peripheral septic embolization, and it can be fatal or cause disabling sequelae. The mainstay of treatment is antibiotic therapy; anticoagulation is often used, but its role is controversial. Surgical treatment is often necessary in case of peripheral septic lesions. In the absence of prospective studies, what little guidance exists on its management is based on case series or on analogy with similar conditions such as other forms of septic thrombophlebitis or non-septic venous thrombosis. Over the last few years, new observational evidence has improved our knowledge of the clinical epidemiology of this condition and highlighted a number of promising management strategies. We provide an overview of the treatment patterns observed in the contemporary era, summarise the arguments proposed so far against or in favour of alternative treatments as well as possible decision rules on the use of anticoagulation, and outline the priorities of ongoing and future observational and interventional research.

Female kinematics and muscle responses in lane change and lane change with braking maneuvers

OBJECTIVE

The primary aim of this article is to extensively study female occupant kinematics and muscle activations in vehicle maneuvers potentially occurring in precrash situations and with different seat belt configurations. The secondary aim is to provide validation data for active human body models (AHBMs) of female occupants in representative precrash loading situations.

METHODS

Front seat female passengers wearing a 3-point seat belt, with either standard or pre-pretensioning functionality, were subjected to multiple autonomously carried-out lane change and lane change with braking maneuvers while traveling at 73 km/h. This article quantifies the head center of gravity and T1 vertebra body (T1) linear and rotational displacements. This article also includes surface electromyography (EMG) data collected from 38 muscles in the neck, torso, and upper and lower extremities, all normalized by maximum voluntary contraction (MVC). The raw EMG data were filtered, rectified, and smoothed. Separate Wilcoxon signed-rank tests were performed on EMG onset and amplitude as well as peak displacements of head and T1 considering 2 paired samples with the belt configuration as an independent variable.

RESULTS

Significantly smaller lateral and forward displacements for head and T1 were found with the pre-pretensioner belt versus the standard belt (P < .05). Averaged muscle activity, mainly in the neck, lumbar extensor, and abdominal muscles, increased up to 16% MVC immediately after the vehicle accelerated in the lateral direction. Muscles in the right and left sides of the body displayed differences in activation time and amplitude relative to the vehicle's lateral motion. For specific muscles, lane changes with the pre-pretensioner belt resulted in earlier muscle activation onsets and significantly smaller activation amplitudes compared to the standard belt (P < .05).

CONCLUSIONS

The presented results from female passengers complement the previously published results from male passengers subjected to the same loading scenarios. The data provided in this article can be used for validation of AHBMs of female occupants in both sagittal and lateral loading scenarios potentially occurring prior to a crash. Additionally, our results show that a pre-pretensioner belt decreases muscle activation onset and amplitude as well as forward and lateral displacements of head and T1 compared to a standard belt, confirming previously published results.

Neck Muscle and Head/Neck Kinematic Responses While Bracing Against the Steering Wheel During Front and Rear Impacts

Drivers often react to an impending collision by bracing against the steering wheel. The goal of the present study was to quantify the effect of bracing on neck muscle activity and head/torso kinematics during low-speed front and rear impacts. Eleven seated subjects (3F, 8 M) experienced multiple sled impacts (Δv = 0.77 m/s; a_peak = 19.9 m/s², Δt = 65.5 ms) with their hands on the steering wheel in two conditions: relaxed and braced against the steering wheel. Electromyographic activity in eight neck muscles (sternohyoid, sternocleidomastoid, splenius capitis, semispinalis capitis, semispinalis cervicis, multifidus, levator scapulae, and trapezius) was recorded unilaterally with indwelling electrodes and normalized by maximum voluntary contraction (MVC) levels. Head and torso kinematics (linear acceleration, angular velocity, angular rotation, and retraction) were measured with sensors and motion tracking. Muscle and kinematic variables were compared between the relaxed and braced conditions using linear mixed models. We found that pre-impact bracing generated only small increases in the pre-impact muscle activity (< 5% MVC) when compared to the relaxed condition. Pre-impact bracing did not increase peak neck muscle responses during the impacts; instead it reduced peak trapezius and multifidus muscle activity by about half during front impacts. Bracing led to widespread changes in the peak amplitude and timing of the torso and head kinematics that were not consistent with a simple stiffening of the head/neck/torso system. Instead pre-impact bracing served to couple the torso more rigidly to the seat while not necessarily coupling the head more rigidly to the torso.

Application of Simulation Methods in Cervical Spine Dynamics

Neck injury is one of the most frequent spine injuries due to the complex structure of the cervical spine. The high incidence of neck injuries in collision accidents can bring a heavy economic burden to the society. Therefore, knowing the potential mechanisms of cervical spine injury and dysfunction is significant for improving its prevention and treatment. The research on cervical spine dynamics mainly concerns the fields of automobile safety, aeronautics, and astronautics. Numerical simulation methods are beneficial to better understand the stresses and strains developed in soft tissues with investigators and have been roundly used in cervical biomechanics. In this article, the simulation methods for the development and application of cervical spine dynamic problems in the recent years have been reviewed. The study focused mainly on multibody and finite element models. The structure, material properties, and application fields, especially the whiplash injury, were analyzed in detail. It has been shown that simulation methods have made remarkable progress in the research of cervical dynamic injury mechanisms, and some suggestions on the research of cervical dynamics in the future have been proposed.

Precollision Medical Diagnoses Predict Chronic Neck Pain Following Acute Whiplash Trauma

OBJECTIVES

The reason why some individuals develop chronic symptoms, whiplash-associated disorder, following whiplash trauma is poorly understood. We explored whether precollision pain-related diagnoses, medically unexplained symptoms, and psychiatric diagnoses are related to whiplash-associated disorder.

MATERIALS AND METHODS

A cohort of 719 individuals exposed to whiplash trauma and subsequently experiencing symptoms within 72 hours (whiplash-exposed cohort) and 3595 matched controls were included in this observational prospective study. At 12 months postcollision, the whiplash-exposed cohort rated their neck pain using the Visual Analog Scale. Data on health were obtained from the Danish National Patient Register for the whiplash-exposed cohort and for the controls for a 5-year period before collision.

RESULTS

The whiplash-exposed cohort had significantly increased incidences of precollision pain-related diagnoses: χ(1)=17.42, P<0.001 and medically unexplained symptoms: χ(1)=22.2, P<0.001 but not psychiatric diagnoses: χ(1)=3.60, P>0.05 compared with controls in the 5-year period. Participants from the whiplash-exposed cohort with precollision pain-related diagnoses (odds ratio=2.46; 95% confidence interval, 1.39; 4.35) and medically unexplained symptoms (odds ratio, 1.72; 95% confidence interval, 1.04; 2.84) had significantly increased odds for neck pain at follow-up.

DISCUSSION

Precollision pain and medically unexplained symptoms predict chronic neck pain following whiplash trauma. This may indicate that a sensitization process was initiated before the collision or that individuals with precollision low threshold for contacting health care services maintain this behavior postcollision. The collision may trigger existing individual vulnerabilities that constitute to be a risk factor for chronic whiplash.

Non-whiplash soft tissue injuries following low-velocity impact collisions: A retrospective analysis

Whiplash is the most common injury reported in low-velocity impact road traffic accidents, but claimants report a range of other soft tissue injuries and we looked at the prevalence of these and any patterns. We retrospectively reviewed reports from the medico-legal practice of an orthopaedic surgeon. We collected data on 609 claimants. Sixty-two per cent were women (p < 0.0001). Majority (90.3%) reported an injury to at least one other area than neck, and 48% of claimants reported shoulder pain. Hand/wrist injuries were almost exclusive to drivers (p = 0.0013). Those with knee injuries were older than those without (p = 0.001). There was a significant difference in the age of patients with different spinal injury patterns (p < 0.0001). Occupational status did not appear to influence the pattern of injuries (p = 0.06). Psychological symptoms were associated with a greater number of body parts injured (p < 0.01). Our data confirm a strong association between these soft tissue injuries and psychological symptoms.

Relationship Between Cervical, Thoracic and Lumbar Spinal Alignments in Automotive Seated Posture

The purpose of this study was to investigate the relationship between cervical, thoracic and lumbar spinal alignments in one automotive occupant seated posture. An image data set of the spinal column in the automotive seated posture, previously acquired by an upright open Magnetic Resonance Imaging system, were reanalysed in this study. Spinal alignments were presented by the geometrical centres of the vertebral bodies extracted from the image data. Cervical, thoracic and lumbar spinal alignments were analysed separately with Multi-Dimensional Scaling (MDS). Based on distribution maps of cervical, thoracic and lumbar spinal alignments created by MDS, representative spinal alignment patterns of the cervical, thoracic and lumbar spines and the relationship between cervical, thoracic and lumbar spinal alignments were investigated. As a result, this study found a correlation between cervical and thoracic spinal alignments in an automotive occupant seated posture. According to representative spinal alignment patterns illustrated by the distribution map of spinal alignments, subjects who had kyphotic cervical spinal alignment tended to have less kyphotic thoracic spinal alignment, while subjects who had lordotic cervical spinal alignment tended to have more kyphotic thoracic spinal alignment. For lumbar spinal alignments, no prominent relationship was found between cervical or thoracic spinal alignment in the seated condition of this study.

Is kinesiophobia and pain catastrophising at baseline associated with chronic pain and disability in whiplash-associated disorders? A systematic review

BACKGROUND

Kinesiophobia and pain catastrophising may be associated with patients' transition from having acute to chronic pain following a whiplash injury.

OBJECTIVE

To systematically review and critically appraise the literature to determine whether kinesiophobia and pain catastrophising are associated with greater likelihood of patients developing chronic pain and disability following a whiplash injury.

DESIGN

A systematic review of the literature DATA SOURCES: Electronic searches of PubMed, AMED, CINAHL, PsycINFO, and PubPsych, and grey literature were undertaken from inception to September 2017.

ELIGIBILITY CRITERIA FOR SELECTING STUDIES

Study selection was based on longitudinal studies evaluating how kinesiophobia and/or pain catastrophising at baseline are associated with pain intensity, disability or both after a whiplash injury.

RESULTS

We included 14 longitudinal studies that described 12 independent cohorts with a total sample of 2733 participants with whiplash-associated disorder. Kinesiophobia at baseline was not associated with pain intensity over time (three studies). Whether kinesiophobia at baseline was associated with disability was unclear as results were conflicting (six studies). There were also conflicting results when we examined the association between pain catastrophising and both pain intensity (five studies) and disability (eight studies).

SUMMARY/CONCLUSIONS

Kinesiophobia at baseline was not associated with pain intensity over time. There were conflicting results for the remaining analyses. The size of the associations was small. The overall quality of the evidence was very low.

TRIAL REGISTRATION NUMBER

CRD42016053864.

Review of average sized male and female occupant models in European regulatory safety assessment tests and European laws: Gaps and bridging suggestions

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.

Surviving ectopic Cushing's syndrome: quality of life, cardiovascular and metabolic outcomes in comparison to Cushing's disease during long-term follow-up

OBJECTIVE

Aim of our study was to analyze long-term outcome of patients with the ectopic Cushing's syndrome (ECS) compared to patients with Cushing's disease (CD) regarding cardiovascular, metabolic, musculoskeletal and psychiatric comorbidities.

DESIGN

Cross-sectional study in patients with ECS and CD in two German academic tertiary care centers.

METHODS

Standardized clinical follow-up examination was performed including health-related quality of life (QoL) in 21 ECS patients in long-term remission (≥18 months since successful surgery). Fifty-nine patients with CD in remission served as controls.

RESULTS

Time from first symptoms to diagnosis of Cushing's syndrome (CS) was shorter in ECS than in CD (8.5 (IQR: 30.3) vs 25 (IQR: 39.0) months, P = 0.050). ECS patients had lower self-reported psychiatric morbidity compared to CD (19% vs 43%, P = 0.050) at follow-up. Moreover, female ECS patients reported favorable scores for QoL in the SF-36 questionnaire (mental health: 92 (IQR: 30) vs 64 (IQR: 32) in CD, P = 0.010) and a Cushing-specific QoL questionnaire (73 (IQR: 18) vs 59 (IQR: 36) in CD, P = 0.030). In a pooled analysis of ECS and CD patients, QoL correlated with time from first symptoms until diagnosis of CS, but not with urinary free cortisol levels or serum cortisol after dexamethasone at the time of diagnosis. Long-term outcomes regarding hypertension, metabolic parameters, bone mineral density and grip strength were comparable in ECS and CD.

CONCLUSIONS

Our data support the concept that time of exposure to glucocorticoid excess appears to be a better predictor than peak serum cortisol levels at the time of diagnosis regarding long-term psychiatric morbidity and QoL.

Effects of whole spine alignment patterns on neck responses in rear end impact

OBJECTIVE

The aim of this study was to investigate the whole spine alignment in automotive seated postures for both genders and the effects of the spinal alignment patterns on cervical vertebral motion in rear impact using a human finite element (FE) model.

METHODS

Image data for 8 female and 7 male subjects in a seated posture acquired by an upright open magnetic resonance imaging (MRI) system were utilized. Spinal alignment was determined from the centers of the vertebrae and average spinal alignment patterns for both genders were estimated by multidimensional scaling (MDS). An occupant FE model of female average size (162 cm, 62 kg; the AF 50 size model) was developed by scaling THUMS AF 05. The average spinal alignment pattern for females was implemented in the model, and model validation was made with respect to female volunteer sled test data from rear end impacts. Thereafter, the average spinal alignment pattern for males and representative spinal alignments for all subjects were implemented in the validated female model, and additional FE simulations of the sled test were conducted to investigate effects of spinal alignment patterns on cervical vertebral motion.

RESULTS

The estimated average spinal alignment pattern was slight kyphotic, or almost straight cervical and less-kyphotic thoracic spine for the females and lordotic cervical and more pronounced kyphotic thoracic spine for the males. The AF 50 size model with the female average spinal alignment exhibited spine straightening from upper thoracic vertebra level and showed larger intervertebral angular displacements in the cervical spine than the one with the male average spinal alignment.

CONCLUSIONS

The cervical spine alignment is continuous with the thoracic spine, and a trend of the relationship between cervical spine and thoracic spinal alignment was shown in this study. Simulation results suggested that variations in thoracic spinal alignment had a potential impact on cervical spine motion as well as cervical spinal alignment in rear end impact condition.

A Female Ligamentous Cervical Spine Finite Element Model Validated for Physiological Loads

Mathematical cervical spine models allow for studying of impact loading that can cause whiplash associated disorders (WAD). However, existing models only cover the male anthropometry, despite the female population being at a higher risk of sustaining WAD in automotive rear-end impacts. The aim of this study is to develop and validate a ligamentous cervical spine intended for biomechanical research on the effect of automotive impacts. A female model has the potential to aid the design of better protection systems as well as improve understanding of injury mechanisms causing WAD. A finite element (FE) mesh was created from surface data of the cervical vertebrae of a 26-year old female (stature 167 cm, weight 59 kg). Soft tissues were generated from the skeletal geometry and anatomical literature descriptions. Ligaments were modeled with nonlinear elastic orthotropic membrane elements, intervertebral disks as composites of nonlinear elastic bulk elements, and orthotropic anulus fibrosus fiber layers, while cortical and trabecular bones were modeled as isotropic plastic-elastic. The model has geometrical features representative of the female cervical spine-the largest average difference compared with published anthropometric female data was the vertebral body depth being 3.4% shorter for the model. The majority the cervical segments compare well with respect to biomechanical data at physiological loads, with the best match for flexion-extension loads and less biofidelity for axial rotation. An average female FE ligamentous cervical spine model was developed and validated with respect to physiological loading. In flexion-extension simulations with the developed female model and an existing average male cervical spine model, a greater range of motion (ROM) was found in the female model.

Sick Leave within 5 Years of Whiplash Trauma Predicts Recovery: A Prospective Cohort and Register-Based Study

BACKGROUND

10-22% of individuals sustaining whiplash trauma develop persistent symptoms resulting in reduced working ability and decreased quality of life, but it is poorly understood why some people do not recover. Various collision and post-collision risk factors have been studied, but little is known about pre-collision risk factors. In particular, the impact of sickness and socioeconomic factors before the collision on recovery is sparsely explored. The aim of this study was to examine if welfare payments received within five years pre-collision predict neck pain and negative change in provisional situation one year post-collision.

METHODS AND FINDINGS

719 individuals with acute whiplash trauma consecutively recruited from emergency departments or primary care after car accidents in Denmark completed questionnaires on socio-demographic and health factors immediately after the collision. After 12 months, a visual analogue scale on neck pain intensity was completed. 3595 matched controls in the general population were sampled, and national public register data on social benefits and any other welfare payments were obtained for participants with acute whiplash trauma and controls from five years pre-collision to 15 months after. Participants with acute whiplash trauma who had received sickness benefit for more than 12 weeks pre-collision had increased odds for negative change in future provisional situation (Odds Ratio (OR) (95% Confidence Interval (CI) = 3.8 (2.1;7.1)) and future neck pain (OR (95%CI) = 3.3 (1.8;6.3)), controlling for other known risk factors. Participants with acute whiplash trauma had weaker attachment to labour market (more weeks of sick leave (χ2(2) = 36.7, p < 0.001) and unemployment (χ2(2) = 12.5, p = 0.002)) pre-collision compared with controls. Experiencing a whiplash trauma raised the odds for future negative change in provisional situation (OR (95%CI) = 3.1 (2.3;4.4)) compared with controls.

CONCLUSIONS

Sick leave before the collision strongly predicted prolonged recovery following whiplash trauma. Participants with acute whiplash trauma had weaker attachment to labour market pre-collision compared with the general population. Neck pain at inclusion predicted future neck pain. Acute whiplash trauma may trigger pre-existing vulnerabilities increasing risk of developing whiplash-associated disorders.

Are non-steroidal anti-inflammatory drugs effective for the management of neck pain and associated disorders, whiplash-associated disorders, or non-specific low back pain? A systematic review of systematic reviews by the Ontario Protocol for Traffic Injury Management (OPTIMa) Collaboration

PURPOSE

To evaluate the effectiveness of non-steroidal anti-inflammatory drugs (NSAIDs) for the management of neck pain and associated disorders (NAD), whiplash-associated disorders, and non-specific low back pain (LBP) with or without radiculopathy.

METHODS

We systematically searched six databases from 2000 to 2014. Random pairs of independent reviewers critically appraised eligible systematic reviews using the Scottish Intercollegiate Guidelines Network criteria. We included systematic reviews with a low risk of bias in our best evidence synthesis.

RESULTS

We screened 706 citations and 14 systematic reviews were eligible for critical appraisal. Eight systematic reviews had a low risk of bias. For recent-onset NAD, evidence suggests that intramuscular NSAIDs lead to similar outcomes as combined manipulation and soft tissue therapy. For NAD (duration not specified), oral NSAIDs may be more effective than placebo. For recent-onset LBP, evidence suggests that: (1) oral NSAIDs lead to similar outcomes to placebo or a muscle relaxant; and (2) oral NSAIDs with bed rest lead to similar outcomes as placebo with bed rest. For persistent LBP, evidence suggests that: (1) oral NSAIDs are more effective than placebo; and (2) oral NSAIDs may be more effective than acetaminophen. For recent-onset LBP with radiculopathy, there is inconsistent evidence on the effectiveness of oral NSAIDs versus placebo. Finally, different oral NSAIDs lead to similar outcomes for neck and LBP with or without radiculopathy.

CONCLUSIONS

For NAD, oral NSAIDs may be more effective than placebo. Oral NSAIDs are more effective than placebo for persistent LBP, but not for recent-onset LBP. Different oral NSAIDs lead to similar outcomes for neck pain and LBP.

Initial healthcare and coping preferences are associated with outcome 1 year after whiplash trauma: a multicentre 1-year follow-up study

OBJECTIVE

Individuals exposed to whiplash collisions have to cope with the stressful event as well as early physical symptoms. As in other chronic pain conditions, coping has been associated with outcome after whiplash. In this study, our aim was to examine whether initial coping preferences were associated with the development of chronic whiplash.

DESIGN

Prospective study.

SETTING

Primary care.

METHODS

740 acute whiplash patients were recruited from emergency units and general practitioners after car collisions in Denmark. Within 10 days postinjury, participants were asked what they believed could help them get better. At 12-month follow-up, the level of neck pain and capability to work was obtained. Whether coping preferences (baseline) were associated with outcome was investigated using multiple regression analyses.

RESULTS

Persistent neck pain was most strongly associated with preferring medications (mean difference=1.24 (95% CI 0.67 to 1.82)) and sickness absence (mean difference=1.18 (95% CI 0.53 to 1.82)). Reduced work capability was most strongly associated with preferring medications (OR=3.53 (95% CI 2.13 to 5.86)), sickness absence (OR=3.05 (95% CI 1.80 to 5.17)) and being referred to a physiotherapist/chiropractor (OR=3.03 (95% CI 1.33 to 6.91)). Active coping was associated with better outcomes: Participants preferring to change their lifestyle were protected against reduced work capability (OR=0.11 (95% CI 0.01 to 0.78)). Individuals who wanted to keep living as usual only (no other preference reported) were protected against neck pain (mean difference -1.62 (95% CI -2.39 to -0.84)) and reduced work capability (OR=0.09 (95% CI 0.01 to 0.64)).

CONCLUSIONS

A simple nine-item measure of coping preferences is associated with the development of chronic neck pain and reduced capability to work following whiplash trauma and may be used to identify individuals at risk of poor recovery.

Sex differences in coping strategies in military survival school

A wealth of research has examined psychological responses to trauma among male military service members, but few studies have examined sex differences in response to trauma, such as coping strategies. This study assessed coping strategies used by male and female U.S. service members completing an intensely stressful mock-captivity exercise, compared strategies by sex, and assessed the relationship between coping and posttraumatic stress symptoms (PTSS). Two hundred service members (78% male) completed self-report surveys before and after mock captivity. Surveys assessed demographics, service characteristics, PTSS, and coping strategies used during mock captivity. Participants used seven coping strategies: denial, self-blame, religion, self-distraction, behavioral disengagement, positive reframing, and planning. Women used denial (p≤.05), self-blame (p≤.05), and positive reinterpretation (p≤.05) strategies more frequently than men, and they had higher PTSS levels following the exercise. Structural equation modeling showed that the relationship between sex and PTSS was fully mediated by coping strategies. The results of this study suggest that reducing the use of maladaptive coping strategies may mitigate PTSS among females. Future efforts should target improving coping during highly stressful and traumatic experiences.

Sex Differences in Patients with Chronic Pain Following Whiplash Injury: The Role of Depression, Fear, Somatization, Social Support, and Personality Traits

BACKGROUND

Chronic whiplash-associated disorders (chronic WAD) cover a large variety of clinical manifestations that can occur after a whiplash injury. Women have an increased risk of developing chronic WAD, and it is suggested that psychosocial factors are related to long-term pain and functioning following whiplash injury and persistence of chronic pain. This leads to the question whether there are sex differences in psychosocial factors in chronic WAD.

METHODS

This study included 117 subjects who had experienced a whiplash injury at least 3 months before the start of the study (mean duration of pain: 67.29 ± 63.86 months, range: 297 months). They were selected as chronically symptomatic, by excluding those who had recovered from their whiplash injury. Psychosocial aspects (including depression, fear, somatization, social support, and personality traits) were assessed by validated questionnaires, and sex differences were tested using a univariate analysis of variance (ANCOVA), with age and time from whiplash injury as covariates.

RESULTS

No differences in depression, fear, somatization, discrepancy in social support personality trait, Neck Disability Index scores, physical functioning, bodily pain, or general health were present between women and men with chronic WAD. Women with chronic WAD reported higher levels of emotional support in problem situations and social companionship.

CONCLUSION

Except for emotional support in problem situations and social companionship, psychosocial factors do not differ between men and women with chronic WAD. These findings imply little to no risk for sex bias in studies investigating psychosocial issues in patients with chronic WAD.

Comparison of pain threshold and duration of pain perception in men and women of different ages

Introduction Pain is a sensory and emotional experience that occurs with the presence of tissue injury, actual or potential. Pain is subjective, and its expression is primarily determined by the perceived intensity of the painful sensation, called the pain threshold. Objective To evaluate whether there are differences in pain threshold (LD) and time to pain perception (TPED) between the gender in different age groups and to analyze the correlation between age and pain threshold in each gender. Methods and procedures Participants were 60 volunteers divided into 6 groups (n = 10 each) according to gender and age (18–33, 34–49, and 50–64 years). The evaluation of perception and pain tolerance was performed by immersing the container with one hand in water at a temperature of 0 °C–2 °C; the latency to withdrawal of the hand from ice water was measured in seconds and was considered a measure of LD. The TPED was reported by each participant as the start time of the painful stimulus. Results We found differences between the LD for G1 (men aged between 18 and 33 years) and G2 (women aged 18 to 33 years) with greater LD for G1 (p = 0.0122) and greater LD for women (p = 0.0094); for other comparisons of LD and TPED, there were no differences (p > 0.05 for all comparisons). Low correlation was found between age progression with increased LD and the TPED only in men (p = 0.01 and r = 0.45 and p = 0.05 and r = 0.34, respectively). Conclusion We conclude that women have a higher pain threshold than men especially when these groups are aged between 18 and 33 years, and in men increasing age correlates with increased TPED and LD.

Association between centralization and directional preference and functional and pain outcomes in patients with neck pain

STUDY DESIGN

Retrospective cohort.

OBJECTIVES

In subjects with neck pain, the present study aimed (1) to describe the prevalence of centralization (CEN), noncentralization (non-CEN), directional preference (DP), and no directional preference (no DP); (2) to determine if age, sex, fear-avoidance beliefs about physical activity, number of comorbid conditions, or symptom duration varies among subjects who demonstrate CEN versus non-CEN and DP versus no DP; and (3) to determine if CEN and/or DP are associated with changes in function and pain.

BACKGROUND

CEN and DP are prevalent among patients with low back pain and should be considered when determining treatment strategies and predicting outcomes; however, these findings are not well investigated in patients with neck pain.

METHODS

Three hundred four subjects contributed data. CEN and DP prevalence were calculated, as was the association between CEN and DP, and age, sex, number of comorbid conditions, fear-avoidance beliefs, and symptom duration. Multivariate models assessed whether CEN and DP predicted change in function and pain.

RESULTS

CEN and DP prevalence were 0.4 and 0.7, respectively. Younger subjects and those with fewer comorbid conditions were more likely to centralize; however, subjects who demonstrated DP were more likely to have acute symptoms. Subjects who centralized experienced, on average, a 3.6-point (95% confidence interval: -0.3, 7.4) improvement in function scores, whereas subjects with a DP averaged a 5.4-point (95% confidence interval: 0.8, 10.0) improvement. Neither CEN nor DP was associated with pain outcomes.

CONCLUSION

DP and, to a lesser extent, CEN represent evaluation categories that are associated with improvements in functional outcomes.

Anthropometric specifications, development, and evaluation of EvaRID--a 50th percentile female rear impact finite element dummy model

OBJECTIVES

Whiplash-associated disorders (WADs), or whiplash injuries, due to low-severity vehicle crashes are of great concern in motorized countries and it is well established that the risk of such injuries is higher for females than for males, even in similar crash conditions. Recent protective systems have been shown to be more beneficial for males than for females. Hence, there is a need for improved tools to address female WAD prevention when developing and evaluating the performance of whiplash protection systems. The objective of this study is to develop and evaluate a finite element model of a 50th percentile female rear impact crash test dummy.

METHODS

The anthropometry of the 50th percentile female was specified based on literature data. The model, called EvaRID (female rear impact dummy), was based on the same design concept as the existing 50th percentile male rear impact dummy, the BioRID II. A scaling approach was developed and the first version, EvaRID V1.0, was implemented. Its dynamic response was compared to female volunteer data from rear impact sled tests.

RESULTS

The EvaRID V1.0 model and the volunteer tests compared well until ∼250 ms of the head and T1 forward accelerations and rearward linear displacements and of the head rearward angular displacement. Markedly less T1 rearward angular displacement was found for the EvaRID model compared to the female volunteers. Similar results were received for the BioRID II model when comparing simulated responses with experimental data under volunteer loading conditions. The results indicate that the biofidelity of the EvaRID V1.0 and BioRID II FE models have limitations, predominantly in the T1 rearward angular displacement, at low velocity changes (7 km/h). The BioRID II model was validated against dummy test results in a loading range close to consumer test conditions (EuroNCAP) and lower severity levels of volunteer testing were not considered.

CONCLUSIONS

The EvaRID dummy model demonstrated the potential of becoming a valuable tool when evaluating and developing seats and whiplash protection systems. However, updates of the joint stiffness will be required to provide better correlation at lower load levels. Moreover, the seated posture, curvature of the spine, and head position of 50th percentile female occupants needs to be established and implemented in future models.

What characterizes individuals developing chronic whiplash?: The Nord-Trøndelag Health Study (HUNT)

OBJECTIVE

Most individuals experiencing whiplash accidents recover rapidly. A considerable proportion, however, develop chronic symptoms. Psychological factors may slow recovery, possibly by increasing the likelihood of other symptoms being misattributed to, and amplified by the whiplash injury. We aimed to investigate how pre-injury mental and somatic symptoms, self-rated health, use of health-services and medications, health-behavior and socio-demographics predict the development of chronic whiplash.

METHODS

Data from two waves of a large, population based study (HUNT2 (baseline) and HUNT3) were used. Individuals reporting no whiplash at baseline were identified in HUNT3. Characteristics reported at baseline were compared between those who had developed chronic whiplash in HUNT3 (n=199) and those who had not (n=20,600), using Pearson's chi-squared tests, independent sample t-tests and logistic regression analyses.

RESULTS

Individuals developing chronic whiplash reported worse baseline health than those reporting no chronic whiplash. Poor self-rated health was a strong risk factor for subsequent chronic whiplash (OR=2.26, 95%CI: 1.68-3.04). Musculoskeletal pain also increased the risk (OR=1.21, 95%CI: 1.15-1.26), as did diffuse somatic symptoms (OR=2.09, 95%CI: 1.47-2.96), use of different health services (OR=1.31, 95%CI: 1.19-1.45), high use of medications (OR=1.28, 95%CI: 1.14-1.43) and symptoms of anxiety (OR=1.93, 95%CI: 1.39-2.68). Physical activity was protective (OR=0.67, 95%CI: 0.49-0.91). Most socio-demographic variables were not significantly associated with chronic whiplash.

CONCLUSION

Poor somatic and mental pre-injury health increased the risk of subsequent chronic whiplash. This suggests that chronic whiplash is not merely an organic disorder, and highlights the importance of individual expectations, symptom reattribution and amplification in development of chronic whiplash.

Health, social, and economic consequences of neck injuries: a controlled national study evaluating societal effects on patients and their partners

STUDY DESIGN

National register-based matched case-control study.

OBJECTIVE

The aim of this study was to estimate the direct and indirect costs of neck injuries, except fractures, in a national sample of patients and their spouses.

SUMMARY OF BACKGROUND DATA

Despite neck injuries causing significant socioeconomic burdens, there is insufficient information about the time course, as well as the effect on their spouses.

METHODS

Using records from the Danish National Patient Registry 1998-2009, all patients with a diagnosis of neck injury and their spouses were identified and compared with randomly chosen controls matched for age, sex, geographical area, and civil status. Direct costs included frequency of primary and hospital sector contacts and procedures and medication. Indirect costs included the effect on labor supply. Social transfer payments were included to illustrate the effect on national accounts. All cost data were extracted from national databases.

RESULTS

The register contributed 94,224 patients, and 372,341 matched controls were identified. The percentages of married or cohabiting individuals were approximately 47.5% in both groups. Patients with neck injury had significantly higher rates of health-related contacts, medication use, and higher socioeconomic costs than controls. To a lesser extent, they also had lower employment rates, and those employed generally had lower incomes. Furthermore, the patients had already presented negative social- and health-related status up to 11 years before the first diagnosis, which became more pronounced for those with the highest costs. The health effects on costs were present regardless of age group and sex, and it was also seen for the patients' spouses.

CONCLUSION

Neck injuries are associated with major socioeconomic consequences for patients, their spouses, and the society. However, the increased expenses during subsequent years cannot be explained by the injury alone, because these patients already had elevated expenses prior to the injury. This indicates some selection of increased vulnerability for both patients and their spouses.

Impaired quality of life in patients in long-term remission of Cushing's syndrome of both adrenal and pituitary origin: a remaining effect of long-standing hypercortisolism?

OBJECTIVE

The determinants that cause impaired quality of life (QOL) in patients in long-term remission of Cushing's syndrome (CS) are unknown. The aim of this study was to get more insight into the patient and disease characteristics related to impaired QOL in these patients.

DESIGN

Cross-sectional study.

METHODS

The QOL of 123 patients in remission of CS (age 52.2 ± 12.0 years, 106 women, duration of remission 13.3 ± 10.4 years, 80% pituitary CS), assessed with seven validated questionnaires, was compared with the QOL of an age- and sex-matched control group (n=105). To investigate the influence of the aetiology of CS on QOL, patients in remission of pituitary and adrenal CS were compared. Furthermore, the influence of hormonal deficiencies, treatment strategy, duration of remission, gender and age on QOL was investigated.

RESULTS

QOL in the total patient group and each patient subgroup was significantly worse on practically all dimensions of questionnaires compared with the control group (P<0.05), except for patients in remission of pituitary CS without hormonal deficiencies who had an impaired QOL on 50% of the QOL dimensions. Subgroup analysis revealed no difference in QOL between different patient groups, especially no difference between patients in remission of adrenal and pituitary CS. Female gender and a shorter duration of remission had a negative influence on QOL in the patient group.

CONCLUSIONS

QOL remains impaired in patients in long-term remission of CS regardless of aetiology, presence of hormonal deficiencies and treatment strategies. More research is needed to establish the causes.