***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 
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    Input: OBJECTIVE To determine , in a group of persons involved in a motor vehicle collision , the contributions of pre-collision health and psychological factors , the social environment , collision-specific factors , and post-collision symptoms , to the new onset of widespread pain ( WP ) . METHODS A prospect i ve cohort study of persons , registered with an insurance company , who had recently experienced a motor vehicle collision . Participants were sent a question naire to assess pre-collision health , collision-specific factors , post-collision health , and WP .  Those reporting WP prior to the collision were excluded from followup . At 12 months , participants were sent a followup question naire to ascertain one-month period prevalence of ( new onset ) WP . RESULTS In total 957 individuals took part in the baseline survey and were eligible for followup . Subsequently , 695 ( 73 % ) completed a question naire at 12 months , of whom 54 ( 7.8 % ) reported new WP . Few collision-specific factors predicted the onset of WP . In contrast , post-collision physical symptoms ( rate ratio 2.5 , 95 % confidence interval 1.2 - 5.1 ) , pre-collision health-seeking behavior ( RR 3.6 , 95 % CI 1.6 - 7.9 ) , pre-collision somatization ( RR 1.7 , 95 % CI 0.99 - 2.8 ) , and perceived initial injury severity ( RR 1.7 , 95 % CI 0.9 - 3.3 ) , in addition to older age ( RR 3.3 , 95 % CI 1.5 - 7.1 ) , were all independently predictive of new onset WP . In combination , these factors accounted for about a 20-fold difference in the risk of new onset WP . CONCLUSION We identified 5 factors that independently predict the onset of WP following a motor vehicle collision . Early identification of this " at-risk " group may allow the targeting of preventive management in those at highest risk of developing future symptoms 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 Objective of the investigation : In a 6-month prospect i ve study of 141 consecutive acute whiplash-injured participants , and 40 acute , ankle-injured controls , pain and tenderness in the neck/head , and at a distant control site , were measured . Basic procedures : Muscle palpation and pressure algometry in five head/neck muscle-pairs were performed after 1 week and 1 , 3 and 6 months after injury . Algometry was performed at a distant control site . Main findings : Whiplash-injured patients had lowered pressure-pain-detection thresholds and higher palpation-score initially in the neck/head , but the groups were similar after 6 months , and the control site was not sensitized . Principal conclusion : Focal , but not generalized , sensitization to musculoskeletal structure is present until 3 months , but not 6 months , after whiplash injury , and probably does not play a major role in the development of late whiplash syndrome . Pressure algometry and palpation are useful clinical tools in the evaluation of neck and jaw pain in acute whiplash injury & 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 UNLABELLED Although previous research suggests that preamputation pain is a risk factor for pain after amputation , little is known about the association between acute postsurgical pain and chronic amputation-related pain . The current prospect i ve study examined the associations of preamputation pain and acute postamputation pain with chronic amputation-related pain . The sample consisted of patients with lower limb amputation ( N = 57 ) who provided both preamputation and postamputation data during a 2-year study period .  Preamputation pain intensity and duration  were assessed before  amputation ; acute phantom limb pain ( PLP ) and residual limb pain ( RLP ) intensity were assessed on postsurgical days 4 and 5 . Acute PLP intensity was the only significant independent predictor of chronic PLP intensity at 6 and 12 months after amputation , whereas preamputation pain intensity was the only significant predictor of chronic PLP intensity at 24 months . Similarly , acute RLP was found to be the best overall predictor of chronic RLP . Other variables ( age , gender , level and etiology of amputation , amount of postsurgical pain medication , and duration of preamputation pain ) were not associated with chronic pain . These results suggest that higher levels of pain either before or soon after amputation might help to identify individuals at greatest risk for chronic pain problems and most in need of early , intensive pain interventions . PERSPECTIVE This study suggests that both preamputation pain and acute pain soon after amputation might be associated with bothersome chronic pain . The results support further research on acute pain mechanisms and the effectiveness of early interventions aim ed at preventing or managing amputation-related pain Background Individuals ' expectations on returning to work after an injury have been shown to predict the duration of time that a person with work-related low back pain will remain on benefits ; individuals with lower recovery expectations received benefits for a longer time than those with higher expectations . The role of expectations in recovery from traumatic neck pain , in particular whiplash-associated disorders ( WAD ) , has not been assessed to date to our knowledge . The aim of this study was to investigate if expectations for recovery are a prognostic factor after experiencing a WAD . Methods and Findings We used a prospect i ve cohort study composed of insurance cl aim ants in Sweden . The participants were car occupants who filed a neck injury cl aim ( i.e. , for WAD ) to one of two insurance companies between 15 January 2004 and 12 January 2005 ( n = 1,032 ) .  Postal question naires were completed shortly ( average 23 d ) after the collision and then again 6 mo later . Expectations for recovery were measured with a numerical rating scale ( NRS ) at baseline , where 0 corresponds to “ unlikely to make a full recovery ” and 10 to “ very likely to make a full recovery . ” The scale was reverse coded and trichotomised into NRS 0 , 1–4 , and 5–10 . The main outcome measure was self-perceived disability at 6 mo postinjury , measured with the Pain Disability Index , and categorised into no/low , moderate , and high disability . Multivariable polytomous logistic regression was used for the analysis . There was a dose response relationship between recovery expectations and disability . After controlling for severity of physical and mental symptoms , individuals who stated that they were less likely to make a full recovery ( NRS 5–10 ) , were more likely to have a high disability compared to individuals who stated that they were very likely to make a full recovery ( odds ratio [ OR ] 4.2 [ 95 % confidence interval ( CI ) 2.1 to 8.5 ] . For the intermediate category ( NRS 1–4 ) , the OR was 2.1 ( 95 % CI 1.2 to 3.2 ) . Associations between expectations and disability were also found among individuals with moderate disability . Conclusions Individuals ' expectations for recovery are important in prognosis , even after controlling for symptom severity . Interventions design ed to increase patients ' expectations may be beneficial and should be examined further in controlled studies Neck pain is the cardinal symptom following whiplash injuries . The trauma mechanism could theoretically lead to both soft tissue and bone injury that could be visualised by means of MRI . From previous quite small trials it seems that MRI does not demonstrate significant tissue damage . Large prospect ively followed cohorts are needed to identify possible clinical ly relevant MRI findings . The objective of this trial was to evaluate ( 1 ) the predictive value of cervical MRI  after whiplash injuries and ( 2 ) the value of repeating MRI examinations after 3 months including sequences with flexion and extension of the cervical spine . Participants were included after rear-end or frontal car collisions . Patients with fractures or dislocations diagnosed by st and ard procedures at the emergency unit were not included .  MRI scans of the cervical spine were performed at baseline and repeated after 3 months . Clinical follow-ups were performed after 3 and 12 months . Outcome parameters were neck pain , headache , neck disability and working ability .  A total of 178 participants had a cervical MRI scan on average 13 days after the injury . Traumatic findings were observed in seven participants . Signs of disc degeneration were common and most frequent at the C5–6 and C6–7 levels . Findings were not associated with outcome after 3 or 12 months . The population had no considerable neck trouble prior to the whiplash injury and the non-traumatic findings represent findings to be expected in the background population . Trauma-related MRI findings are rare in a whiplash population screened for serious injuries in the emergency unit and not related to a specific symptomatology . Also , pre-existing degeneration is not associated with prognosis & NA ; Predictors of outcome following whiplash injury are limited to socio‐demographic and symptomatic factors , which are not readily amenable to secondary and tertiary intervention . This prospect i ve study investigated the predictive capacity of early measures of physical and psychological impairment on pain and disability 6 months following whiplash injury . Motor function ( ROM ; kinaesthetic sense ; activity of the superficial neck flexors ( EMG ) during cranio‐cervical flexion ) , quantitative sensory testing ( pressure , thermal pain thresholds , brachial plexus provocation test ) , sympathetic vasoconstrictor responses and psychological distress ( GHQ‐28 , TSK , IES ) were measured in 76 acute whiplash participants . The outcome measure was Neck Disability Index scores at 6 months . Stepwise regression analysis was used to predict the final NDI score . Logistic regression analyses predicted membership to one of the three groups based on final NDI scores ( < 8 recovered , 10–28 mild pain and disability , > 30 moderate/severe pain and disability ) . Higher initial NDI score ( 1.007–1.12 ) , older age ( 1.03–1.23 ) , cold hyperalgesia ( 1.05–1.58 ) , and acute post‐traumatic stress ( 1.03–1.2 ) predicted membership to the moderate/severe group . Additional variables associated with higher NDI scores at 6 months on stepwise regression analysis were 
    Output:
    
Additional promising factors include physical factors of cold hyperalgesia and loss of neck range of movement , although the latter is inconsistent .
Psychological factors of pain catastrophizing , symptoms of post-traumatic stress and recovery perceptions are also prognostic of poor recovery and the presence of depressed mood is inconsistent .
Although more research is required to vali date predictive models , some factors show consistent predictive capacity and could be used in clinical practice as potential indicators of poor recovery .
It is not known if the specific targeting of modifiable prognostic indicators can be achieved or will lead to improved outcomes