***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: A retrospective analysis of insurance data was made of 600 individuals cl aim ing compensation for whiplash following motor vehicle accidents . Three hundred r and omly selected cl aim ants who had settled their injury cl aims within 9 months of the accident were compared with 300 who had settled more than 24 months after the accident . We compared the two groups to identify possible risk factors for prolonged recovery , for which settlement time greater than 24 months was a marker . Variables considered included demographic factors , type of collision , degree of vehicle damage , workers compensation , prior cl aim or neck disability , treatment and time to settlement .  Consulting a solicitor was associated with a highly significant , four-fold increase of late settlement of the cl aim . A concurrent workers ’ compensation cl aim , prior neck disability and undergoing physiotherapy or chiropractic treatment were weakly associated with late settlement . The degree of damage to the vehicle ( as indicated by cost of repairs ) was not a significant predictor of late settlement . Late settlement may be the direct effect of legal intervention , independent of the severity of the injury . Whilst the financial benefit to the cl aim ant of consulting a solicitor is apparent , the benefit of prolonged disability is not . It may be to the advantage of both insurers and cl aim ants if those likely to proceed to late settlement could be recognised early and their cl aims settled expeditiously We performed a prospect i ve study of patients with a whiplash trauma to the cervical spine to describe the incidence of these injuries and to evaluate prognostic factors for disability and recovery .  A total of 356 patients were enrolled in the study . All the patients received a comprehensive question naire after the injury , and 296 cases responded to the follow-up protocol more than 1 year after the accident . Disability related to the whiplash trauma was used as the outcome variable for the assessment of prognostic factors . The annual incidence of acute whiplash trauma in the catchment area was 4.2 per 1,000 inhabitants and 3.2 per 1,000 for whiplash-associated disorder grade s 1–3 . Thirty-two percent reported persisting disability at follow-up . The following factors were significantly associated with a poor prognosis : pretraumatic neck pain , low educational level , female gender , and whiplash-associated disorder grade s 2–3 Ninety-three cases with a car-accident soft-tissue injury of the cervical spine were studied prospect ively . Neck pain and stiffness were the main initial symptoms , while 4 cases had abnormal neurologic signs . At follow-up , on an average 2 years after the accident , 42 percent had recovered completely , 15 percent had minor discomfort , and 43 percent had discomfort sufficient to interfere with their capacity for work . The statistical analysis of 17 factors , including acute symptoms and physical findings , as well as the forces and directions of impact , head rests , radiographs , length , and sex , did not reveal any factor of prognostic importance Hypersensitivity to a variety of sensory stimuli is a feature of persistent whiplash associated disorders ( WAD ) . However , little is known about sensory disturbances from the time of injury until transition to either recovery or symptom persistence . Quantitative sensory testing  ( pressure and thermal pain thresholds , the brachial plexus provocation test ) , the  sympathetic vasoconstrictor reflex and psychological distress ( GHQ‐28 ) were prospect ively measured in 76 whiplash subjects within 1 month of injury and then 2 , 3 and 6 months post‐injury . Subjects were classified at 6 months post‐injury using scores on the Neck Disability Index : recovered ( < 8 ) , mild pain and disability ( 10–28 ) or moderate/severe pain and disability ( > 30 ) . Sensory and sympathetic nervous system tests were also measured in 20 control subjects . All whiplash groups demonstrated local mechanical hyperalgesia in the cervical spine at 1 month post‐injury . This hyperalgesia persisted in those with moderate/severe symptoms at 6 months but resolved by 2 months in those who had recovered or reported persistent mild symptoms . Only those with persistent moderate/severe symptoms at 6 months demonstrated generalised hypersensitivity to all sensory tests . These changes occurred within 1 month of injury and remained unchanged throughout the study period . Whilst no significant group differences were evident for the sympathetic vasoconstrictor response , the moderate/severe group showed a tendency for diminished sympathetic reactivity . GHQ‐28 scores of the moderate/severe group were higher than those of the other two groups . The differences in GHQ‐28 did not impact on any of the sensory measures . These findings suggest that those with persistent moderate/severe symptoms at 6 months display , soon after injury , generalised hypersensitivity suggestive of changes in central pain processing mechanisms . This phenomenon did not occur in those who recover or those with persistent mild symptoms The present study aim ed to establish criteria for delayed recovery after whiplash injury using a 1-year prospect i ve cohort study . 117 whiplash patients referred from primary care and 16 whiplash patients recruited from the insurance company . At baseline all patients underwent  neurological , radiological and psychosocial factors assessment  and testing of  personality traits , well-being , cognitive ability and cognitive functioning . According to the logistic regression in patients referred from primary care the following initial variables are in significant relationship with poor outcome at 1 year : impaired neck movement , history of pretraumatic headache , history of head trauma , higher age , initial neck pain intensity , initial headache intensity , nervousness score , neuroticism score and test score on focused attention . Employing these variables , correct prediction of outcome at 1 year was found in 88 % of patients recruited from the insurance company . Authors conclude that a comprehensive assessment of whiplash patients early after trauma enables physicians to identify patients at risk of delayed recovery & NA ; Dysfunction in the motor system is a feature of persistent whiplash associated disorders . Little is known about motor dysfunction in the early stages following injury and of its progress in those persons who recover and those who develop persistent symptoms . This study measured prospect ively , motor system function ( cervical range of movement ( ROM ) , joint position error ( JPE ) and activity of the superficial neck flexors ( EMG )  during a test of cranio‐cervical flexion ) as well as a measure of fear of re‐injury ( TAMPA ) in 66 whiplash subjects within 1 month of injury and then 2 and 3 months post injury . Subjects were classified at 3 months post injury using scores on the neck disability index : recovered ( < 8 ) , mild pain and disability ( 10–28 ) or moderate/severe pain and disability ( > 30 ) . Motor system function was also measured in 20 control subjects . All whiplash groups demonstrated decreased ROM and increased EMG ( compared to controls ) at 1 month post injury . This deficit persisted in the group with moderate/severe symptoms but returned to within normal limits in those who had recovered or reported persistent mild pain at 3 months . Increased EMG persisted for 3 months in all whiplash groups . Only the moderate/severe group showed greater JPE , within 1 month of injury , which remained unchanged at 3 months . TAMPA scores of the moderate/severe group were higher than those of the other two groups . The differences in TAMPA did not impact on ROM , EMG or JPE . This study identifies , for the first time , deficits in the motor system , as early as 1 month post whiplash injury , that persisted not only in those reporting moderate/severe symptoms at 3 months but also in subjects who recovered and those with persistent mild symptoms Abstract . Outcome following  whiplash injury of the cervical spine is variable , and the pathology of those with prolonged symptoms is uncertain . We undertook a prospect i ve study in 25 patients to identify whether those with prolonged symptoms following whiplash injury exhibit a rise in serum creatine kinase consistent with significant muscle damage at the time of injury . Transient rise in creatine kinase level was seen in only 2 of 25 patients , neither of whom complained of prolonged symptoms . Of the 8 patients who developed chronic symptoms following whiplash injury , none demonstrated a serum creatine kinase rise . Prolonged symptoms following whiplash injury can not be explained by biochemically measurable muscle damage OBJECTIVE An earlier pilot study suggested that the late whiplash syndrome is uncommon in Greece . The purpose of the present study is to extend the evaluation to a larger sample , and include the prevalence of specific symptoms in the evaluation . METHODS In a prospect i ve , cohort study , a total of 180 accident victims were consecutively recruited following Emergency ward presentation .  A st and ard question naire asked about neck pain , headache , shoulder pain , limb numbness or pain , and dizziness . Accident victims were followed for 6 months . RESULTS In the initial 4 weeks after the accident , accident victims reported neck pain , headache , shoulder pain , arm numbness or pain , and dizziness , but at 4 weeks more than 90 % had recovered from these , the remainder of the subjects having minor symptoms ( not requiring therapy ) , and returning to their pre-accident state of health ( which included minor symptoms ) . There were no cases of chronic disability . CONCLUSION In Greece , symptoms after an acute whiplash injury are self-limiting , brief , and do not appear to evolve into the so-called late whiplash syndrome One hundred and seventeen r and omly selected patients were assessed for different psychological variables ( personality traits , wellbeing , and cognitive ability ) in relation to somatic symptoms after common whiplash .  Patients were investigated at an average of 7.4 ( SD 4.2 ) days after trauma and again at three and six months . The course of recovery could not be explained by the patients ' disposition . The results indicated that improvement in wellbeing was associated with recovery from somatic symptoms . There was , however , cognitive impairment in patients who suffered from symptoms . These findings support the view that the psychological and cognitive problems of patients with common whiplash  are mainly related to somatic symptoms It is generally accepted that the incidence of whiplash associated disorders is increasing in all industrialised countries , despite the almost universal fitment of head restraints in at least the front seats of cars . This is usually attributed to the fact that few people can be observed to follow the st and ard recommendations as regards head restraint positioning , that is , level with the head vertically and as close to the head as possible horizontally . This study set out to determine whether any other factors , in addition to head restraint adjustment , could be found which would influence the severity of whiplash injury . This was done by linking medical assessment of real-world accident victims with engineering assessment of the accident vehicles . A r and om sample of road accident victims suffering from whiplash associated disorder was studied . The vehicles they had been travelling in were examined to assess impact severity and , where possible , measurements were made of seat and head restraint adjustment with the subject sitting in the vehicle . All subjects were interviewed to assess the disability result ing from their injuries , and their progress was followed for 12 months . The results were subjected to statistical analysis to try to determine relationships between severity of injury ( as measured by result ant disability ) and a number of occupant- and vehicle-related factors . A significant proportion of the sample had suffered lumbar strain injury in addition to whiplash , and these were excluded from the present analysis . Frontal impact victims suffered symptoms indistinguishable from those of rear impact victims . The beneficial effects of good head restraint adjustment could not be clearly demonstrated , and some trends , especially in rear impacts , where the benefits of a well-adjusted restraint should have been very clear , indicated that larger distances from head to restraint were associated with lower disability . The paper discusses these counter-intuitive results and their implication Background : Exposure to a whiplash injury implies a risk for development of chronic disability and h and icap , with reported frequencies ranging from 0 % to 50 % in follow-up studies . The exact risk for development of chronic whiplash syndrome is not known . Objective : To prospect ively determine the sensitivity and specificity of five possible predictors for h and icap following a whiplash injury . Methods : In a 1-year prospect i ve study of persons with acute whiplash injury ( n = 141 ) and control subjects who had acute ankle distortion ( n = 40 ) , pain intensity , number of nonpainful neurologic complaints , cervical mobility , workload during extension and flexion of the neck , and results of psychometric assessment were recorded . The consecutively sample d injured persons were assessed with structured and semistructured question naires , and underwent neurologic examination after 1 week and 1 , 3 , 6 , and 12 months . After 3 to 4 years , participants with whiplash injury were question ed about legal issues . Results : After 1 year , 11 ( 7.8 % ) persons with whiplash injury had not returned to usual level of activity or work . The best single estimator of h and icap was the cervical range-of-motion test , which had a sensitivity of 73 % and a specificity of 91 % ( p < 0.01 , Cox regression analysis ) . Accuracy and specificity increased to 94 % and 99 % when combined with pain intensity and other complaints . This increase was gained at the expense of a reduced sensitivity . Initiation of lawsuit within first month after injury did not influence recovery . Conclusion : The cervical range-of-motion test has a high sensitivity in prediction of h and icap after acute whiplash injury . The value of cervical range-of-motion test is further improved by additional recording of symptoms and pain intensity & NA ; Psychological distress is a feature of chronic whiplash‐associated disorders , but little is known of psychological changes from soon after injury to either recovery or symptom persistence . This study prospect ively measured psychological distress ( General Health Question naire 28 , GHQ‐28 ) , fear of movement/re‐injury 
    Output:
    
These data suggest that recovery occurs for a substantial proportion of subjects in the initial 3 months after the accident but after this time recovery rates level off .
Pain and disability symptoms also reduce rapidly in the initial months after the accident but show little improvement after 3 months have elapsed .