***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: Background The evidence that exercise intervention is effective for treatment of chronic low back pain comes from trials that are not placebo-controlled . Objective The purpose of this study was to investigate the efficacy of motor control exercise for people with chronic low back pain . Design This was a r and omized , placebo-controlled trial . Setting The study was conducted in an outpatient physical therapy department in Australia . Patients The participants were 154 patients with chronic low back pain of more than 12 weeks ’ duration . Intervention Twelve sessions of motor control exercise ( ie , exercises design ed to improve function of specific muscles of the low back region and the control of posture and movement ) or placebo ( ie , detuned ultrasound therapy and detuned short-wave therapy ) were conducted over 8 weeks . Measurements Primary outcomes were pain intensity , activity ( measured by the Patient-Specific Functional Scale ) , and patient 's global impression of recovery measured at 2 months . Secondary outcomes were pain ; activity ( measured by the Patient-Specific Functional Scale ) ; patient 's global impression of recovery measured at 6 and 12 months ; activity limitation ( measured by the Rol and -Morris Disability Question naire ) at 2 , 6 , and 12 months ; and risk of persistent or recurrent pain at 12 months . Results The exercise intervention  improved activity and patient 's global impression of recovery but did not clearly reduce pain at 2 months . The mean effect of exercise on activity ( measured by the Patient-Specific Functional Scale ) was 1.1 points ( 95 % confidence interval [CI]=0.3 to 1.8 ) , the mean effect on global impression of recovery was 1.5 points ( 95 % CI=0.4 to 2.5 ) , and the mean effect on pain was 0.9 points ( 95 % CI=−0.01 to 1.8 ) , all measured on 11-point scales . Secondary outcomes also favored motor control exercise . Limitation Clinicians could not be blinded to the intervention they provided . Conclusions Motor control exercise produced short-term improvements in global impression of recovery and activity , but not pain , for people with chronic low back pain . Most of the effects observed in the short term were maintained at the 6- and 12-month follow-ups Objective .—The aim of this study was to determine whether clinical indicators of cutaneous allodynia predict the success of migraine therapy with sumatriptan  using a brief question naire Objective To investigate the efficacy of a programme of manual therapy and exercise treatment compared with placebo treatment delivered by physiotherapists for people with chronic rotator cuff disease . Design R and omised , participant and single assessor blinded , placebo controlled trial . Setting Metropolitan region of Melbourne , Victoria , Australia . Participants 120 participants with chronic ( > 3 months ) rotator cuff disease recruited through medical practitioners and from the community . Interventions The active treatment comprised a manual therapy and home exercise programme ; the placebo treatment comprised inactive ultrasound therapy and application of an inert gel . Participants in both groups received 10 sessions of individual st and ardised treatment over 10 weeks . For the following 12 weeks , the active group continued the home exercise programme and the placebo group received no treatment . Main outcome measures The primary outcomes were pain and function measured by the shoulder pain and disability index , average pain on movement measured on an 11 point numerical rating scale , and participants ’ perceived global rating of overall change . Results 112 ( 93 % ) participants completed the 22 week trial . At 11 weeks no difference was found between groups for change in shoulder pain and disability index ( 3.6 , 95 % confidence interval −2.1 to 9.4 ) or change in pain ( 0.7 , −0.1 to 1.5 ) ; both groups showed significant improvements . More participants in the active group reported a successful outcome ( defined as “ much better ” ) , although the difference was not statistically significant : 42 % ( 24/57 ) of active participants and 30 % ( 18/61 ) of placebo participants ( relative risk 1.43 , 0.87 to 2.34 ) . The active group showed a significantly greater improvement in shoulder pain and disability index than did the placebo group at 22 weeks ( between group difference 7.1 , 0.3 to 13.9 ) , although no significant difference existed between groups for change in pain ( 0.9 , −0.03 to 1.7 ) or for the percentage of participants reporting a successful treatment outcome ( relative risk 1.39 , 0.94 to 2.03 ) . Several secondary outcomes favoured the active group , including shoulder pain and disability index function score , muscle strength , interference with activity , and quality of life . Conclusion A st and ardised programme of manual therapy and home exercise did not confer additional immediate benefits for pain and function compared with a realistic placebo treatment that controlled for therapists ’ contact in middle aged to older adults with chronic rotator cuff disease . However , greater improvements were apparent at follow-up , particularly in shoulder function and strength , suggesting that benefits with active treatment take longer to manifest . Trial registration Clinical trials NCT00415441 & NA ; Widespread sensory hypersensitivity is present in acute whiplash and is associated with poor recovery . Decreased nociceptive flexion reflex ( NFR ) thresholds ( spinal cord hyperexcitability ) are a feature of chronic whiplash but have not been investigated in the acute to chronic injury stage . This study compared the temporal development of sensory hypersensitivity and NFR responses from soon after injury to either recovery or to transition to chronicity . It also aim ed to identify predictors of persistent spinal cord hyperexcitability . Pressure and cold pain thresholds , NFR responses ( threshold and pain VAS )  were prospect ively measured in 62 participants at <3 weeks , 3 and 6 months post whiplash injury and in 22 healthy controls on two occasions a month apart . Pain levels and psychological distress ( GHQ‐28 ; IES ) were measured at baseline . Whiplash participants were classified at 6 months post‐injury using the Neck Disability Index : recovered ( ≤8 % ) , mild pain and disability ( 10–28 % ) or moderate/severe pain and disability ( ≥30 % ) . All whiplash groups  demonstrated spinal cord hyperexcitability ( lowered NFR thresholds ) at 3 weeks post‐injury . This hyperexcitability persisted in those with moderate/severe symptoms at 6 months but resolved in those who recovered or reported lesser symptoms at 6 months . In contrast generalized sensory hypersensitivity ( pressure and cold ) was only ever present in those with persistent moderate/severe symptoms and remained unchanged throughout the study period . This suggests different mechanisms underlie sensory hypersensitivity and NFR responses . In multivariate analyses only initial NDI scores ( p = 0.003 ) were a unique predictor of persistent spinal cord hyperexcitability indicating possible ongoing peripheral nociception following whiplash injury The aim of this study was to evaluate the function of pain modulating systems subserving diffuse noxious inhibitory controls ( DNICs ) in primary headaches . DNICs were examined in 24 migraineurs , 17 patients with chronic tension-type headache ( CTTH ) and 20 healthy subjects by means of nociceptive flexion RIII reflex and the cold pressor test ( CPT ) as heterotopic noxious conditioning stimulation ( HNCS ) . The subjective pain thresholds ( Tp ) and the RIII reflex threshold ( Tr ) were significantly lower in CTTH vs. controls . In controls a significant inhibition of the RIII reflex was observed during the CPT ( -30± , P < 0.05 ) . Conversely , migraine and CTTH patients  showed facilitation ( + 31± , P < 0.05 and + 40± , P < 0.01 , respectively ) of the RIII reflex during the HNCS . This study demonstrates a dysfunction in systems subserving DNICs in both migraine and CTTH . Impairment of endogenous supraspinal pain modulation systems may contribute to the development and /or maintenance of central sensitization in primary headaches UNLABELLED Pain catastrophizing is among the most robust predictors of pain outcomes , and a disruption in endogenous pain-inhibitory systems is 1 potential mechanism that may account for increased pain among individuals who report higher pain catastrophizing . Pain catastrophizing may negatively influence diffuse noxious inhibitory controls ( DNIC ) , a measure of endogenous pain inhibition , through complex anatomical circuitry linking cortical responses to pain with processes that modulate pain . The current study examined whether DNIC mediated the relationship between catastrophizing and pain among 35 healthy young adults and examined the moderating effects of sex to determine whether the magnitude or direction of associations differed among men and women .  DNIC was assessed using pressure pain thresholds on the forearm before and during a cold pressor task . Using bias-corrected bootstrapped confidence intervals , results showed that diminished DNIC was a significant partial mediator of the relation between greater pain-related catastrophizing and more severe pain ratings . Participant sex moderated these associations ; higher catastrophizing predicted lower DNIC for men and women , however , the effect of catastrophizing on pain ratings was partially mediated by DNIC for women only . These findings further support the primary role of pain catastrophizing in modulation of pain outcomes . PERSPECTIVE These findings support the hypothesis that the heightened pain reported by individuals higher in pain catastrophizing may be related to a disruption in the endogenous modulation of pain , operationalized by assessing DNIC . Whether interventions that reduce pain catastrophizing affect pain outcomes via effects on DNIC is in need of investigation OBJECTIVE To investigate to what extent a single 60-minute session of transcutaneous electrical nerve stimulation ( TENS ) would modify chronic clinical pain , acute experimental pain , and the flexion reflex evoked in chronic low back pain patients . STUDY DESIGN Thirty young subjects with chronic low back pain were r and omly allocated to two groups , receiving either TENS or placebo stimulation to the lumbosacral region for 60 minutes . The flexion reflex was elicited by an electrical stimulation applied to the subject 's right sole and recorded electromyographically from the biceps femoris and the tibialis anterior muscles . MAIN OUTCOME MEASURES Subjective sensation of low back pain and the electrically induced pain were measured by two separate visual analog scales , termed VAS(LBP ) and VAS(FR ) , respectively . Data obtained before , during , and 60 minutes after TENS and placebo stimulations were analyzed using repeated measures ANOVA . RESULTS The VAS(LBP ) score was significantly reduced to 63.1 % of the prestimulation value after TENS ( p<.001 ) , but the reduction was negligible after placebo stimulation ( to 96.7 % , p = .786 ) . In contrast , no significant change was found in the VASFR score ( p = .666 ) and the flexion reflex area ( p = .062 ) during and after stimulation within each group and between the two groups ( p = .133 for VASFR and p = .215 for flexion reflex area ) . CONCLUSIONS The same TENS protocol had different degrees of antinociceptive influence on chronic and acute pain in chronic low back pain patients OBJECTIVE : To test the feasibility of creating a valid and reliable checklist with the following features : appropriate for assessing both r and omised and non-r and omised studies ; provision of both an overall score for study quality and a profile of scores not only for the quality of reporting , internal validity ( bias and confounding ) and power , but also for external validity . DESIGN : A pilot version was first developed , based on epidemiological principles , review s , and existing checklists for r and omised studies . Face and content validity were assessed by three experienced review ers and reliability was determined using two raters assessing 10 r and omised and 10 non-r and omised studies . Using different raters , the checklist was revised and tested for internal consistency ( Kuder-Richardson 20 ) , test-retest and inter-rater reliability ( Spearman correlation coefficient and sign rank test ; kappa statistics ) , criterion validity , and respondent burden . MAIN RESULTS : The performance of the checklist improved considerably after revision of a pilot version . The Quality Index had high internal consistency ( KR-20 : 0.89 ) as did the subscales apart from external validity ( KR-20 : 0.54 ) . Test-retest ( r 0.88 ) and inter-rater ( r 0.75 ) reliability of the Quality Index were good . Reliability of the subscales varied from good ( bias ) to poor ( external validity ) . The Quality Index correlated highly with an existing , established instrument for assessing r and omised studies ( r 0.90 ) . There was little difference between its performance with non-r and omised and with r and omised studies . Raters took about 20 minutes to assess each paper ( range 10 to 45 minutes ) . CONCLUSIONS : This study has shown that it is feasible to develop a checklist that can be used to assess the method ological quality not only of r and omised controlled trials but also non-r and omised studies . It has also shown that it is possible to produce a checklist that provides a profile of the paper , alerting review ers to its particular method ological strengths and weaknesses . Further work is required to improve the checklist and the training of raters in the assessment of external validity OBJECTIVE To determine whether abnormalities of peripheral and central nociceptive sensory input processing exist outside areas of spontaneous pain in patients with fibromyalgia ( FM ) as compared with controls , by using quantitative sensory testing ( QST ) and a neurophysiologic paradigm independent from subjective reports . METHODS A total of 164 out patients with FM who were attending a self-management program were invited to participate in the study . Data for 85 patients were available and were compared with those for 40 non-FM controls matched for age and sex .  QST was performed 
    Output:
    
The results indicate that there is evidence of central hyperexcitability in people with chronic musculoskeletal pain .
Our review also suggests that shorter inter-pulse duration tends to yield smaller variability in NFR threshold .