***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: 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 & 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 There has been little investigation into whether or not differences exist in the nature of physical impairment associated with neck pain of whiplash and insidious origin . This study examined the neck flexor synergy during performance of the cranio-cervical flexion test , a test targeting the action of the deep neck flexors . Seventy-five volunteer subjects participated in this study and were equally divided between Group 1 , asymptomatic control subjects , Group 2 , subjects with insidious onset neck pain and Group 3 , subjects with neck pain following a whiplash injury .  The cranio-cervical flexion test was performed in five progressive stages of increasing cranio-cervical flexion range . Subjects ' performance was guided by feedback from a pressure sensor inserted behind the neck which monitored the slight flattening of the cervical lordosis which occurs with the contraction of longus colli .  Myoelectric signals ( EMG ) were detected from the muscles during performance of the test . The results indicated that both the insidious onset neck pain and whiplash groups had higher measures of EMG signal amplitude ( normalized root mean square ) in the sternocleidomastoid during each stage of the test compared to the control subjects ( all P<0.05 ) and had significantly greater shortfalls from the pressure targets in the test stages ( P<0.05 ) . No significant differences were evident between the neck pain groups in either parameter indicating that this physical impairment in the neck flexor synergy is common to neck pain of both whiplash and insidious origin 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 ; 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 : ROM loss and diminished sympathetic reactivity . Higher initial NDI score ( 1.03–1.28 ) , greater psychological distress ( GHQ‐28 ) ( 1.04–1.28 ) and decreased ROM ( 1.03–1.25 ) predicted subjects with persistent milder symptoms from those who fully recovered . These results demonstrate that both physical and psychological factors play a role in recovery or non‐recovery from whiplash injury . This may assist in the development of more relevant treatment methods for acute whiplash Abstract Higher initial levels of pain and disability , older age , cold hyperalgesia , impaired sympathetic vasoconstriction and moderate post‐traumatic stress symptoms have been shown to be associated with poor outcome 6 months following whiplash injury . This study prospect ively investigated the predictive capacity of these variables at a long‐term follow‐up . Sixty‐five of an initial cohort of 76 acutely injured whiplash participants were followed to 2–3 years post‐accident .  Motor function ( ROM ; kinaesthetic sense ; activity of the superficial neck flexors ( EMG ) during cranio‐cervical flexion ) , quantitative sensory testing ( pressure , thermal pain thresholds and brachial plexus provocation test ) , sympathetic vasoconstrictor responses and psychological distress ( GHQ‐28 , TSK and IES ) were measured . The outcome measure was Neck Disability Index ( NDI ) scores . Participants with ongoing moderate/severe symptoms at 2–3 years continued to manifest decreased ROM , increased EMG during cranio‐cervical flexion , sensory hypersensitivity and elevated levels of psychological distress when compared to recovered participants and those with milder symptoms . The latter two groups showed only persistent deficits in cervical muscle recruitment patterns . Higher initial NDI scores ( OR 1.00–1.1 ) , older age ( OR 1.00–1.13 ) , cold hyperalgesia ( OR 1.1–1.13 ) and post‐traumatic stress symptoms ( OR 1.03–1.2 ) remained significant predictors of poor outcome at long‐term follow‐up ( r2 = 0.56 ) . The robustness of these physical and psychological factors suggests that their assessment in the acute stage following whiplash injury will be important BACKGROUND AND PURPOSE Physical mechanisms are the possible factors involved in the development and maintenance of long-term h and icaps after acute whiplash injury . This study prospect ively examined the role of active neck mobility , cervical and extra-cervical pains , as well as non-painful complaints after a whiplash injury as predictors for subsequent h and icap . METHODS Consecutive acute whiplash patients ( n = 688 ) were interviewed and examined by a study nurse after the median of 5 days after injury , and divided into a high- or a low-risk group by an algorithm based on pain intensity , number of non-painful complaints and active neck mobility [ active cervical range of motion ( CROM ) ] . All 458 high-risk patients and 230 low-risk patients received mailed question naires after 3 , 6 and 12 months . Two examiners examined all high-risk patients ( n = 458 ) and 41 consecutive low-risk patients at median 11 , 109 , 380 days after injury . The main outcome measures were : h and icaps , severe headaches , neck pain and neck disability . RESULTS The relative risk for a 1-year disability increased by 3.5 with initial intense neck pain and headaches , by 4.6 times with reduced CROM and by four times with multiple non-painful complaints . CONCLUSION Reduced active neck mobility , immediate intense neck pain and headaches and the presence of multiple non-painful complaints are the important prognostic factors for a 1-year h and icap after acute whiplash Study Design . An experimental study of motor and sensory function and psychological distress in subjects with acute whiplash injury . Objectives . To characterize acute whiplash injury in terms of motor and sensory systems dysfunction and psychological distress and to compare subjects with higher and lesser levels of pain and disability . Summary of Background Data . Motor system dysfunction , sensory hypersensitivity , and psychological distress are present in chronic whiplash associated disorders ( WAD ) , but little is known of such factors in the acute stage of injury . As higher levels of pain and disability in acute WAD are accepted as signs of poor outcome , further characterization of this group from those with lesser symptoms is important . Material s and Methods .  Motor function ( cervical range of movement [ ROM ] , joint position error [ JPE ] ; activity of the superficial neck flexors [ EMG ] during a test of cranio-cervical flexion ) , quantitative sensory testing ( pressure , thermal pain thresholds , and responses to the brachial plexus provocation test ) , and psychological distress ( GHQ-28 , TAMPA , IES ) were measured in 80 whiplash subjects ( WAD II or III ) within 1 month of injury , as were 20 control subjects . Results . Three subgroups were identified in the cohort using cluster analysis based on the Neck Disability Index : those with mild , moderate , or severe pain and disability . All whiplash groups demonstrated decreased ROM and increased EMG compared with the controls ( all P < 0.01 ) . Only the 
    Output:
    
The predictive value of examining the presence of cervical motor dysfunctions was doubtful .
The course and predictive value of initial reduced cervical mobility was inconsistent .
Cervical motor dysfunctions are present soon after whiplash trauma persisting in those with moderate/severe symptoms .
However , these dysfunctions have limited predictive value , and hence may not explain the complex clinical picture of whiplash-associated disorders .