Validity and internal consistency of a whiplash specific disability measure
From: Spine. 2004 Feb 1;29(3):263-8
Whiplash injuries frequently occur following motor vehicle collisions. Analysis of police reported tow away crashes from Victoria, Australia (1987-1998) showed a significant percentage of occupants had whiplash injury (8% for frontal crashes and 18% for rear crashes). Data provided by the New South Wales Compulsory Third Party insurers to the Motor Accidents Association’s Claims Register showed whiplash to be the most frequently recorded crash injury in this Australian state. Further to this, approximately 60% of the injuries resulting from vehicle crashes causing disability in Sweden between 1990 and 1995 were whiplash injuries.
The Quebec Task Force on Whiplash associated disorders defined whiplash as an acceleration-deceleration mechanism of energy transfer to the neck which may result in bony or soft tissue injuries. Whiplash associated disorders can be thought of as the clinical manifestations of, or the disability caused by, whiplash injury and may include biologic, psychological, and social symptoms of the potential tissue damage.
Disability is an umbrella term for impairments, activity limitations, or participation restrictions within an environmental context. Traditionally, the focus in the whiplash associated disorders literature has been on measurement of impairments. There is increasing recognition, however, of the importance of measuring disability in the assessment of patients with whiplash associated disorders.
In the absence of a condition specific disability outcome measure for whiplash, generic disability measures are available to health professionals. Generic measures have been used to measure disability associated with whiplash associated disorders. These generic measures may quantify disability in a broad range of illnesses, but disease-specific measures address disabilities directly caused by the disease. Using generic outcome measures for disorders specific to whiplash injury means risking overlooking changes specific to whiplash. In general, disease-specific measures are thought to be more sensitive to changes in the patient’s health status, as these measure changes that are relevant to the patient, compared with generic measures. The absence of a whiplash specific questionnaire supports the development of a new disability outcome measure specific for patients with whiplash.
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Kyphosed seated postures: extending concepts of postural health beyond the office
From: J Occup Rehabil. 2008 Mar;18(1):35-45. Epub 2008 Feb 7
The harmful effects of sustained sitting and the health of the spine are well documented. The focus of much of this investigation has been sedentary occupations. However, how people sit during leisure hours can impact on the health of the spine both in and out of working hours. In this study a literature search was conducted using Amed, Cinahl and OVID Medline databases. Papers published between 1985 and 2007 were selected for review. These included epidemiological and experimental studies that explored the relationships between seated postures and health of the lumbar spine. Until recently there was confusion in the scientific literature as to which seated postures were least harmful: lordosed or kyphosed. This article reviews and analyses these conflicts in relation to leisure sitting.
Analysis of the literature demonstrates that kyphosed seated postures when sustained are more harmful to the health of the lumbar spine than lordosed seated postures. There is a misconception amongst designers and users of leisure seating that kyphosed relaxed postures are comfortable and that comfort equates with health. It is argued that sustained kyphosed postures are insidiously harmful to the spine in that they may contribute to disc degeneration in the absence of pain. Sustained kyphosed postures also adversely affect spinal ligaments, muscles and joints and lead to neuromuscular and cumulative trauma disorders and loss of spinal stability. Recent research demonstrates that postures popularly assumed in recreational or leisure seating lead to cumulative damage to soft tissues of the spine. These effects may still be present at the commencement of the following work day. In the prevention of work disability caused by sustained sitting, health professionals must consider the impact of leisure seating design and recreational sitting behaviour.
One-year randomized controlled trial with different physical activity programs to reduce musculoskeletal symptoms in the neck and shoulders among office workers
From: Scand J Work Environ Health. 2008 Feb;34(1):55-65
This study evaluates the effect of two different worksite physical activity interventions on neck and shoulder symptoms, together with perceived work ability and sick leave among office workers. An examiner-blinded randomized controlled trial was conducted with 549 office workers allocated to one of three intervention groups: one with specific resistance training of the neck and shoulder region (N=180), one with all-round physical exercise (N=187), and one which acted as a reference group, which was informed about general health promoting activities but did not include a physical activity program (N=182). Questionnaires were filled out at baseline and after 1 year of training.
The duration and intensity of neck and shoulder symptoms was lower after the specified worksite physical-activity interventions than in the reference group. On an intervention group level, specific resistance training was not more effective than all-round physical exercise in reducing the duration and intensity of neck and shoulder symptoms. However, those asymptomatic at baseline had a significant lower prevalence of neck-shoulder symptoms at follow up when allocated to the specific resistance training group than placed in the all-round physical exercise group or reference group. At baseline the work ability index was close to 90% of the maximum score, and the mean sick leave was 5 days per year, both being unaffected by the interventions.
Different physical activity interventions were successful in reducing neck and shoulder symptoms, and specific resistance training was superior to all-round physical exercise in the primary prevention of such symptoms. The initially relatively high work ability index was the most probable reason for no further increase in work ability index. Likewise the mean sick leave the year before the intervention was very low, and it was probably not possible to reduce it further.
Cervical helical axis characteristics and its center of rotation during active head and upper arm movements – comparisons of whiplash associated disorders, non specific neck pain and asymptomatic individuals
From: J Biomech. 2008 Aug 14; [Epub ahead of print]
The helical axis model can be used to describe translation and rotation of spine segments. The aim of this study was to investigate the cervical helical axis and its center of rotation during fast head movements (side rotation and flexion/extension) and ball catching in patients with non specific neck pain or pain due to whiplash injury as compared with matched controls. The aim was also to investigate correlations with neck pain intensity. A finite helical axis model with a time varying window was used. The intersection point of the axis during different movement conditions was calculated. A repeated-measures ANOVA model was used to investigate the cervical helical axis and its rotation center for consecutive levels of 15 degrees during head movement. Irregularities in axis movement were derived using a zero crossing approach. In addition, head, arm and upper body range of motion and velocity were observed. A general increase of axis irregularity that correlated to pain intensity was observed in the whiplash group. The rotation center was superiorly displaced in the non specific neck pain group during side rotation, with the same tendency for the whiplash group. During ball catching, an anterior displacement (and a tendency to an inferior displacement) of the center of rotation and slower and more restricted upper body movements implied a changed movement strategy in neck pain patients, possibly as an attempt to stabilize the cervical spine during head movement.
Cervicogenic headache
From: Pol Merkur Lekarski. 2008 Jun;24(144):549-51 Article in Polish
In 2004 cervicogenic headache (neck related headache) was introduced into ICD-10 classification.The reasons of cervicogenic headache are changes within bones, soft tissue and nervous structures of cervical spine section. The pain may spread to the neck, occipital area of skull, area of jaw and eyeballs, and arms. There are many theories trying to explain spreading of the pain outside the area innervated by C1, C2 and C3 cervical roots. Their common denominator is communication between fibres running in those roots and neurons of trigeminal nerve. Many authors describe a possibility of such connection through the jelly-like nucleus of the trigeminal nerve located in the back funiculi of spinal cord. In this mechanism, the pain conducted via occipital nerves may affect activity of neurons of the trigeminal nerve and influence areas innervated by the trigeminal nerve. In general case history and physical examination are sufficient to make a diagnosis. Additional radiological and imaging examinations support this diagnosis. According to some authors, the necessary condition to make a diagnosis of cervicogenic headache is finding the changes of spondylosis nature of the cervical spine section (neck arthritis or degenerative disc disease) in additional examinations. In doubtful cases, diagnostic blockade of greater occipital nerve, resulting in headache relief, supports finally a diagnosis. Any treatment includes pharmacotherapy, rehabilitation, psychotherapy and surgical methods. The purpose of the study is to view literature on cervicogenic headache which causes many diagnostic problems and hence makes it difficult to choose effective treatment.
Head-turned postures increase the risk of cervical facet capsule injury during whiplash
From: Spine. 2008 Jul 1;33(15):1643-9
Injury to the cervical facet capsular ligaments is a potential mechanism for chronic neck pain after acute whiplash injury. Distending the facet capsule by injecting contrast media has produced whiplash like pain patterns in normal individuals, and anesthetic blocks have isolated the cervical facet joints as the source of pain in about half of a chronic whiplash population. More recently, in vivo animal models of facet capsule loading have shown that group III and IV afferents (thought to mediate pain) from the facet capsule have a graded electrical response to mechanical loading of the facet joint in the goat and have suggested that a capsular ligament strain threshold exists above which allodynia pain in response to a normally nonnoxious stimulus is produced. These data support a facet capsule based mechanism for whiplash injury, but do not establish whether human capsular ligaments are injured in the low speed rear end collisions to which many whiplash injuries are attributed.
Whiplash patients who had their head turned at impact have more severe and persistent symptoms than patients who were facing forward. These findings have prompted biomechanical studies using human cadaveric necks to investigate why a head turned posture increases injury potential. Dynamic rear impact tests of prerotated ligamentous spines (occiput-T1) produce increased neck flexibility (interpreted as injury) in extension, lateral bending and axial rotation. Though concentrated in the lower cervical spine, these injuries were not isolated to particular spinal ligaments. Detailed measurements of the strain field in the facet capsule have also shown that a head-turned posture generates higher capsular strains than a neutral head posture, but the quasi static loads applied during those tests were limited to pure neck flexion/extension moments and did not include the axial compression or posterior shear present during whiplash loading. Thus the question of how a head turned posture combined with multiaxial whiplash loads affects facet capsular ligament strain has yet to be answered.
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Sitting with adjustable ischial and back supports: biomechanical changes
From: Spine. 2003 Jun 1;28(11):1113-21
Low back pain is acute or chronic pain involving the lumbosacral, buttock, and/or thigh. Discogenic low back pain is aggravated by the sitting position, which is necessary in many occupations and daily activities. About 100 million workdays are lost annually in the United States due to low back pain. Despite improved knowledge and health care resources for spinal pathology, chronic disability resulting from nonspecific low back pain is rising exponentially. Although the causes of discogenic low back pain are multifactorial and complex, sitting postures could increase stresses within the disc and contribute to disc degeneration and pain. Two major occupational risk factors are static muscle load and flexed curvature of the lumbar spine; both are involved in seated work tasks.
During sitting, the head, arm and trunk weight is carried mainly by the ischial tuberosities and surrounding tissues. High pressure at the tuberosities is closely associated with high load to the spine. A significant mechanical spine loading is associated with low back pain resulting from trunk muscle coactivation. Ischial and lower back interface pressure vary with different sitting postures and body positioning. Repositioning of the lumbar support to redistribute the interface pressure and load is essential in preventing low back pain associated with inappropriate sitting in a working environment. Therefore, a device that decreases the sitting pressure and load carried by the ischial tuberosity may decrease forces within the disc and associated degeneration and pain.
Physiologic lumbar lordosis in the standing position ranges from 40° to 60°, with the lordosis occurring mainly at S1-L5 and L4-L5, and with the sacral inclination ranging from 30° to 40°. Compared to standing or lying supine, sitting could cause the pelvis to rotate posteriorly, resulting in decreased sacral inclination and lumbar lordosis and increased forces at the discs. A number of investigators have reported interaction between low back pain and biomechanical changes such as decreased lumbar lordosis, malalignment of lumbar curvature, and narrowing of disc spaces. Williams et al reported that use of a lumbar roll that increased lumbar lordosis reduced low back pain, and the chair backrest also helps increase the lumbar lordosis and decrease intradiscal pressure.
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Incidence of shoulder and neck pain in a working population: effect modification between mechanical and psychosocial exposures at work? Results from a one year follow up of the Malmö shoulder and neck study cohort
From: J Epidemiol Community Health. 2005 Sep;59(9):721-8
Work related musculoskeletal disorders and complaints constitute an important health problem in many industrialised countries, as they account for a large number of working days lost and considerable workers compensation and disability payments. For a long time, low back pain has been the dominant problem. However, pain from the shoulder and neck region now seems to occur more frequently. The prevalence of shoulder and neck symptoms is highest in the 45–65 year age bracket, as well as among women, manual workers, and certain ethnic groups.
However, its aetiology is still incompletely understood. Mechanical exposure at work and psychosocial conditions within and without the workplace, in addition to lifestyle and individual variables (age, previous symptoms, etc) are frequently discussed as causal factors in the literature.
Shoulder and neck symptoms have been linked to jobs with highly repetitive work, static work, and work above shoulder level. However, mechanical exposure explains only part of these complaints. The role of psychosocial factors in the workplace has therefore received increasing attention. On the job pressure, monotonous work, and a high perceived workload have also been associated with musculoskeletal symptoms just as much as working situations characterised by high psychological demands, low decision latitude, and low social support.
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Does musculoskeletal discomfort at work predict future musculoskeletal pain?
From: Ergonomics. 2008 May;51(5):637-48
The objective of this prospective cohort study was to evaluate if peak or cumulative musculoskeletal discomfort may predict future low back, neck or shoulder pain among symptom free workers. At baseline, discomfort per body region was rated on a 10 point scale six times during a working day. Questionnaires on pain were sent out three times during follow-up. Peak discomfort was defined as a discomfort level of 2 at least once during a day; cumulative discomfort was defined as the sum of discomfort during the day. Reference workers reported a rating of zero at each measurement.
Peak discomfort was a predictor of low back pain (relative risk (RR) 1.79), neck pain (RR 2.56), right or left shoulder pain (RR 1.91 and 1.90). Cumulative discomfort predicted neck pain (RR 2.35), right or left shoulder pain (RR 2.45 and 1.64). These results suggest that both peak and cumulative discomfort could predict future musculoskeletal pain.
Disability in subacute whiplash patients: Usefulness of the Neck Disability Index
From: Spine J. 2008 August ;33(18)630-635
Whiplash describes a process of hyperextension and hyperflexion of the cervical musculature that may result from motor vehicle collisions. The incidence of whiplash has been estimated to be of 1 case per 1000 habitants per year in Western societies, nevertheless available studies report conflicting rates. Symptoms associated with whiplash problems typically resolve in a relatively brief time (days or weeks), but chronic pain, and long-term disability may occur in 10% to 40% of the cases.
The prevention and treatment of chronic disabling pain in whiplash patients has shown to be elusive. On the one hand, predictive factors of chronic disabling problems in whiplash patients are far from being completely elucidated. Although one can hypothesize that factors from different levels (i.e., physiology, thoughts, feelings, and behavior) and units (i.e., individual, dyad, and context) of analysis play a role, very few and inconsistent findings are available. On the other hand, there is limited evidence about what is the most beneficial treatment for whom and under what circumstances. The use of many different outcome variables and assessment instruments may be responsible, in part at least, of the problems encountered in this area of research to compare results across studies and extract definitive conclusions.
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