***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: Study Design . Controlled study , measuring head repositioning error ( HRE ) using an electrogoniometric device . Objective . To compare HRE in neutral position , axial rotation and complex postures of patients with whiplash-associated disorders ( WAD ) to that of control subjects . Summary of Background Data . The presence of kinesthetic alterations in patients with WAD is controversial . Methods . In 26 control subjects and 29 patients with WAD ( aged 22–74 years ) , head kinematics was sample d using a 3-dimensional electrogoniometer mounted using a harness and a helmet . All tasks were realized in seated position . The repositioning tasks included neutral repositioning after maximal flexion-extension , eyes open and blindfolded , repositioning at 50 ° of axial rotation , and repositioning at 50 ° of axial rotation combined to 20 ° of ipsilateral bending . The flexion-extension , ipsilateral bending , and axial rotation components of HRE were considered . A multiple-way repeated- measures analysis of variance was used to compare tasks and groups . Results . The WAD group displayed a reduced flexion-extension range ( P = 1.9 × 10−4 ) , and larger HRE during flexion-extension and repositioning tasks ( P = 0.009 ) than controls . Neither group nor task affected maximal motion velocity . Neutral HRE of the flexion-extension component was larger in blindfolded condition ( P = 0.03 ) . Ipsilateral bending and axial rotation HRE components were smaller than the flexion-extension component ( P = 7.1 × 10−23 ) . For pure rotation repositioning , axial rotation HRE was significantly larger than flexion-extension and ipsilateral bending repositioning error ( P = 3.0 × 10−23 ) . Ipsilateral bending component of HRE was significantly larger combined tasks than for pure rotation tasks ( P = 0.004 ) . Conclusions . In patients with WAD  , range of motion and head repositioning accuracy were reduced . However , the differences were small . Vision suppression and task type influenced HRE Background and Purpose To date , no studies have investigated the predictive validity of variables from the initial examination to identify patients with neck pain who are likely to benefit from thoracic spine thrust manipulation . The purpose of this study was to develop a clinical prediction rule ( CPR ) to identify patients with neck pain who are likely to experience early success from thoracic spine thrust manipulation . Subjects This was a prospect i ve , cohort study of patients with mechanical neck pain who were referred for physical therapy . Methods Subjects underwent a st and ardized examination  and then a series of thoracic spine thrust manipulation techniques . They were classified as having experienced a successful outcome at the second and third sessions based on their perceived recovery . Potential predictor variables were entered into a stepwise logistic regression model to determine the most accurate set of variables for prediction of treatment success . Results Data for 78 subjects were included in the data analysis , of which 42 had a successful outcome . A CPR with 6 variables was identified . If 3 of the 6 variables ( positive likelihood ratio=5.5 ) were present , the chance of experiencing a successful outcome improved from 54 % to 86 % . Discussion and Conclusion The CPR provides the ability to a priori identify patients with neck pain who are likely to experience early success with thoracic spine thrust manipulation . However , future studies are necessary to vali date the rule OBJECTIVE To compare cervical kinematics during functional motion in patients with neck pain and in asymptomatic participants using a novel virtual reality assessment . DESIGN Clinical comparative trial . SETTING Participants were recruited from university staff and students , and from a local physical therapy clinic . PARTICIPANTS Patients with chronic neck pain ( n=25 ) and asymptomatic participants ( n=42 ) . INTERVENTIONS Not applicable . MAIN OUTCOME MEASURES Kinematic measures ( response time , peak and mean velocity , number of velocity peaks , time to peak velocity percentage ) were sample d while participants were engaged in the virtual game . Group and motion direction differences were assessed with a 2-way repeated- measures analysis of variance , Tukey-Kramer testing , and contrast analysis when relevant . RESULTS Participants with neck pain had lower peak and mean velocities than the asymptomatic participants ( P<.0001 ) . They also demonstrated a greater number of velocity peaks , indicating impaired motion smoothness ( P=.0036 ) . No significant group differences were found for response time or for time to peak velocity percentage . Cervical rotations were significantly faster and smoother than flexion and extension movements ( P<.05 ) . The overall impairment percentage in velocity and smoothness of cervical motion in patients with neck pain ranged from 22 % to 44 % compared with asymptomatic participants . CONCLUSIONS Velocity and smoothness of cervical motion were more restricted in patients with chronic neck pain than found previously . Unlike range of motion and other static measurements , these dynamic variables reflect functional cervical motion and therefore contribute to a better underst and ing of the impairment associated with neck pain . Because the ability to move quickly in response to external stimuli is a commonly occurring phenomenon , this deficit is highly relevant to clinical assessment and management OBJECTIVE To investigate cervicocephalic kinesthetic sensibility ( head repositioning accuracy to subjective straight ahead ) in patients with chronic , nontraumatic cervical spine pain . DESIGN A prospect i ve , 2-group , observational design . SETTING An outpatient chiropractic clinic in the United Kingdom . PARTICIPANTS Eleven patients ( 6 men , 5 women ; mean age + /- st and ard deviation , 41.1 + /- 13.3 yr ; range , 18 - 55 yr ) with chronic , nontraumatic cervical spine pain ( mean duration , 24 + /- 18 mo ) , with no evidence of cervical radiculopathy and /or myelopathy or any other neurologic disorder . Eleven asymptomatic , unimpaired volunteers ( 5 men , 6 women ; mean age , 39.3 + /- 10.3 yr ; range , 28 - 54 yr ) with no history of whiplash or other cervical spine injury or pain served as controls . MAIN OUTCOME MEASURES Cervicocephalic kinesthetic sensibility was investigated by testing the ability of blindfolded participants to relocate accurately the head on the trunk , to a subjective straight-ahead position , after a near-maximal active movement of the head in the horizontal or vertical plane . The active cervical range of motion and the duration and intensity of neck pain were also recorded . RESULTS Mann-Whitney U testing indicated that the patient ( P ) group was no less accurate in head repositioning than the control ( C ) group for all movement directions except flexion ( median global positioning error [ 95 % confidence interval ] , P = 5.7 degrees [ 5.03 - 9.10 ] , C = 4.2 degrees [ 3.17 - 5.32 ] ; p < .05 ) . CONCLUSIONS Nontraumatic neck pain patients show little evidence of impaired cervicocephalic kinesthetic sensibility . These results contrast with studies of chronic cervical pain patients in which the origin was not controlled or involved a cervical whiplash injury Study Design . Prospect i ve r and omized study . Objective . To investigate differences in physical functional outcome in patients with radiculopathy due to cervical disc disease , after structured physiotherapy alone ( consisting of neck-specific exercises with a cognitive-behavioral approach ) versus after anterior cervical decompression and fusion ( ACDF ) followed by the same structured physiotherapy program . Summary of Background Data . No earlier studies have evaluated the effectiveness of a structured physiotherapy program or postoperative physical rehabilitation after ACDF for patients with magnetic resonance imaging – verified nerve compression due to cervical disc disease . Methods . Our prospect i ve r and omized study included 63 patients with radiculopathy and magnetic resonance imaging – verified nerve root compression , who were r and omized to receive either ACDF in combination with physiotherapy or physiotherapy alone .  For 49 of these patients , an independent examiner measured functional outcomes , including active range of neck motion , neck muscle endurance , and h and -related functioning before treatment and at 3- , 6- , 12- , and 24-month follow-ups . Results . There were no significant differences between the 2 treatment alternatives in any of the measurements performed ( P = 0.17–0.91 ) . Both groups showed improvements over time in neck muscle endurance ( P ⩽ 0.01 ) , manual dexterity ( P ⩽ 0.03 ) , and right-h and grip strength ( P = 0.01 ) . Conclusion . Compared with a structured physiotherapy program alone , ACDF followed by physiotherapy did not result in additional improvements in neck active range of motion , neck muscle endurance , or h and -related function in patients with radiculopathy . We suggest that a structured physiotherapy program should precede a decision for ACDF intervention in patients with radiculopathy , to reduce the need for surgery . Level of Evidence : OBJECTIVE To investigate the reliability and discriminative ability of a new test design ed to detect accuracy of neck movements . DESIGN Repeated- measures . Case-control . SETTING University musculoskeletal research clinic in Icel and . PARTICIPANTS Twenty women ( mean age + /- st and ard deviation [ SD ] , 30.8+/-9.1 y ; range , 18 - 49 y ) with chronic whiplash-associated disorders ( WAD ) grade s I and II ( duration , 6 mo-6 y ) , with current pain score on a visual analog scale of 46.8+/-21.8 , and a disability score on the Northwick Park Neck Pain Disability Index of 45%+/-14 % . Twenty asymptomatic women ( mean age + /- SD , 29.3+/-8.6 y ; range , 18 - 48 y ) with no history of whiplash or insidious onset neck pain served as controls . INTERVENTION A slowly moving object appeared on a computer screen and traced an unpredictable movement path that the subjects were required to follow by moving their heads . Three r and omly ordered movement patterns were tested . MAIN OUTCOME MEASURE A new software program connected to a 3Space Fastrak system  was used to measure the mean absolute error ( in millimeters ) of 3 trials in each movement pattern . RESULTS The mean differences ( + /-2 SD ) between days 1 and 2 were.01+/-.64 mm for the asymptomatic group and .33+/-1.80 mm for the WAD group . The between-day intraclass correlation coefficients were between.60 and .77 for the asymptomatic group and .79 and .86 for the WAD group . Repeated- measures analysis of variance revealed a significant difference between groups ( P=.02 ) . The Tukey post hoc test showed significant between-group differences for each movement pattern ( P</=.05 ) . In each successive trial , a slight improvement for the asymptomatic group and a slight worsening for the WAD group were detected . CONCLUSIONS Better reliability was detected for the asymptomatic group than for the WAD group . The test could discriminate between the asymptomatic group versus the chronic WAD group Knowledge on the spinal kinematics and muscle activation of the cervical and thoracic spine during functional task would add to our underst and ing of the performance and interplay of these spinal regions during dynamic condition . The purpose of this study was to examine the influence of chronic neck pain on the three-dimensional kinematics and muscle recruitment pattern of the cervical and thoracic spine during an overhead reaching task involving a light weight transfer by the upper limb . Synchronized measurements of the three-dimensional spinal kinematics and electromyographic activities of cervical and thoracic spine were acquired in thirty individuals with chronic neck pain and thirty age- and gender-matched asymptomatic controls . Neck pain group showed a significantly decreased cervical velocity and acceleration while performing the task . They also displayed with a predominantly prolonged coactivation of cervical and thoracic muscles throughout the task cycle . The current findings highlighted the importance to examine differential kinematic variables of the spine which are associated with changes in the muscle recruitment in people with chronic neck pain . The results also provide an insight to the appropriate clinical intervention to promote the recovery of the functional disability commonly reported in patients with neck pain disorders Study Design . Test-retest and case-control study design ed to detect accuracy of cervical spine movements by comparing 3 incrementally difficult movement patterns . An asymptomatic group , a nontrauma neck pain group , and a group with whiplash-associated disorders , Grade II , were tested ( n = 18 in each group ) . Objective . To determine the test-retest reliability and the discriminative validity of the new Fly method . Summary of Background Data . A lack of reliable and valid measures for grading the deficits of movement control in the cervical spine makes it impossible to prescribe treatment appropriate to each patient 's respective impairment level . Methods . Head tracking of a moving fly which appeared on a computer screen . Easy , medium , and difficult patterns , each of which was repeated 3 times in r and om order , were tested . Amplitude accuracy ( deviation of movements ) , directional accuracy ( time on target , undershoots vs. overshoots ) were compared across patterns and groups on 2 occasions , 1 week apart . Results . The intraclass correlation coefficient2,1 ranged from 0.53 to 0.82 for both variables , except for the subvariable “ overshoots ” ( 0.14–0.42 ) . The limits of agreement ( LOA ) were progressively wider across patterns ( easy – medium – difficult ) and groups ( asymptomatic – nontrauma – whiplash-associated disorder ) . Analysis of variance with repeated measures revealed significant differences between patterns within each group and between groups respectively for both outcome variables ( P < 0.001 ) . Conclusion . The Fly method provides reliable and valid measures for movement control of the cervical spine . Higher means and wider LOA across patterns and subject groups are reasoned 
    Output:
    
Conclusions People with neck pain appear to have reduced active RoM , movement speed , and head repositioning accuracy when compared with controls .