human
***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 Systematic review and best evidence synthesis . OBJECTIVES To describe the prevalence and incidence of  neck pain and disability in workers ; to identify risk factors for neck pain in workers ; to propose an etiological diagram ; and to make recommendations for future research . SUMMARY OF BACKGROUND DATA Previous review s of the etiology of neck pain in workers relied on cross-sectional evidence . Recently published cohorts and r and omized trials warrant a re- analysis of this body of research . METHODS We systematic ally search ed Medline for literature published from 1980 - 2006 . Retrieved articles were review ed for relevance . Relevant articles were critically appraised . Articles judged to have adequate internal validity were included in our best evidence synthesis . RESULTS One hundred and nine papers on the burden and determinants of neck pain in workers were scientifically admissible . The annual prevalence of neck pain varied from 27.1 % in Norway to 47.8 % in Québec , Canada . Each year , between 11 % and 14.1 % of workers were limited in their activities because of neck pain . Risk factors associated with neck pain in workers include age , previous musculoskeletal pain , high quantitative job dem and s , low social support at work , job insecurity , low physical capacity , poor computer workstation design and work posture , sedentary work position , repetitive work and precision work . We found preliminary evidence that gender , occupation , headaches , emotional problems , smoking , poor job satisfaction , awkward work postures , poor physical work environment , and workers ' ethnicity may be associated with neck pain . There is evidence that interventions aim ed at modifying workstations and worker posture are not effective in reducing the incidence of neck pain in workers . CONCLUSION Neck disorders are a significant source of pain and activity limitations in workers . Most neck pain results from complex relationships between individual and workplace risk factors . No prevention strategies have been shown to reduce the incidence of neck pain in workers Neck pain is more prevalent in office workers than in the general community . To date , findings from prospect i ve studies that investigated causal relationships between putative risk factors and the onset of neck pain in this population have been limited by high loss to follow-up . The aim of this research was to prospect ively evaluate a range of risk factors for neck pain in office workers , using vali date d and reliable objective measures as well as attain an estimate of 1-year incidence . We assembled a cohort of 53 office workers without neck pain and  measured individual , physical , workplace and psychological factors at  baseline . We followed participants for 1 year to measure the incidence of neck pain . We achieved 100 % participant follow-up . Cox regression analysis was applied to examine the relationship between the putative risk factors and the cumulative incidence of neck pain . The 1-year incidence proportion of  neck pain in Australian office workers was estimated in this study to be 0.49 ( 95 % CI 0.36–0.62 ) . Predictors of neck pain with moderate to large effect sizes were female gender ( HR : 3.07 ; 95 % CI : 1.18–7.99 ) and high psychological stress ( HR : 1.64 ; 95 % CI : 0.66–4.07 ) . Protective factors included increased mobility of the cervical spine ( HR : 0.44 ; 95 % CI : 0.19–1.05 ) and frequent exercise ( HR : 0.64 ; 95 % CI : 0.27–1.51 ) . These results reveal that neck pain is common in Australian office workers and that there are risk factors that are potentially modifiable Objectives Complaints of the arms , neck , and shoulders in general and computer-related disorders in particular affect many office workers in economically developed countries . However , with the increased use of computer systems in developing countries , the associated musculoskeletal symptoms and risk factors are yet to be investigated . The study investigates the relationship between work-related physical and psychosocial characteristics and symptoms of the arms , neck , and shoulders in an African economically developed worksite . Methods A prospect i ve cohort study with 1-year follow-up was conducted . Data were used from 250 computer office workers in Khartoum , Sudan . Data were collected using the Arabic version of the Maastricht Upper Extremity Question naire . Prevalence rates for symptoms were calculated and the categories of risk factors being evaluated consisted of physical , psychological , and individual risk factors . Multivariable logistic regression analysis was used to identify risk factors associated with complaints that were expressed as odds ratios ( ORs ) with 95 % confidence intervals ( CIs ) . Results The 1-year follow-up prevalence rate was 0.63 ( 95 % CI : 0.58 - 0.70 ) for neck symptoms , 0.56 ( 95 % CI : 0.45 - 0.66 ) for shoulder symptoms , and 0.46 ( 95 % CI : 0.42 - 0.59 ) for symptoms of the forearms/h and s. Three main risk factors were significantly associated with the presence of symptoms : ( 1 ) time pressure [ OR : 1.31 ( 1.00 to 1.90 ) P=0.05 ] , ( 2 ) task difficulty [ OR : 1.85 ( 1.73 to 1.99 ) P=0.03 ] , and ( 3 ) previous history of symptoms [ OR : 4.62 ( 2.20 to 9.35 ) P=0.01 ] . Conclusions The targeted office workers in Sudan are reporting symptoms in the neck , shoulders , and forearms . Work-related psychological factors predicted more significantly the presence of symptoms in the targeted population Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more The aim of this study is to investigate if there is a change in oxygen saturation and blood flow in the different parts of the trapezius muscle in office workers with and without trapezius myalgia during a st and ardized computer task .  Twenty right-h and ed office workers participated ; ten were recruited based on pain in the trapezius and ten as matching controls . Subjects performed a combination of typing and mousing tasks for 60 min at a st and ardized workstation .  Muscle tissue oxygenation and blood flow data were collected from the upper trapezius ( UT ) , the middle trapezius ( MT ) and the lower trapezius ( LT ) , both on the left and right side at seven moments ( at baseline and every tenth minute during the 1-h typing task ) by use of the oxygen to see device . In all three parts of the trapezius muscle , the oxygen saturation and blood flow decreased significantly over time in a similar pattern ( p < 0.001 ) . Oxygenation of the left and right UT was significantly higher compared to the other muscle parts ( p < 0.001 ) . Oxygen saturation for the MT was significantly lower in the cases compared to the control group ( p = 0.027 ) . Blood flow of the UT on the right side was significantly lower than the blood flow on the left side ( p = 0.026 ) . The main finding of this study was that 1 h of combined workstation tasks result ed in decreased oxygen saturation and blood flow in all three parts of the trapezius muscle . Future research should focus on the influence of intervention strategies on these parameters Non-r and omised studies of the effects of interventions are critical to many areas of healthcare evaluation , but their results may be biased . It is therefore important to underst and and appraise their strengths and weaknesses . We developed ROBINS-I ( “ Risk Of Bias In Non-r and omised Studies - of Interventions ” ) , a new tool for evaluating risk of bias in estimates of the comparative effectiveness ( harm or benefit ) of interventions from studies that did not use r and omisation  to allocate units ( individuals or clusters of individuals ) to comparison groups . The tool will be particularly useful to those undertaking systematic review s that include non-r and omised studies OBJECTIVE In the course of performing systematic review s on the prevalence of low back and neck pain , we required a tool to assess the risk of study bias . Our objectives were to ( 1 ) modify an existing checklist and ( 2 ) test the final tool for interrater agreement . STUDY DESIGN AND SETTING The final tool consists of 10 items addressing four domains of bias plus a summary risk of bias assessment . Two research ers tested the interrater agreement of the tool by independently assessing 54 r and omly selected studies .  Interrater agreement overall and for each individual item was assessed using the proportion of agreement and Kappa statistic . RESULTS Raters found the tool easy to use , and there was high interrater agreement : overall agreement was 91 % and the Kappa statistic was 0.82 ( 95 % confidence interval : 0.76 , 0.86 ) . Agreement was almost perfect for the individual items on the tool and moderate for the summary assessment . CONCLUSION We have addressed a research gap by modifying and testing a tool to assess risk of study bias . Further research may be useful for assessing the applicability of the tool across different conditions Physical and psychosocial stressors in the workplace have been independently associated with the development of  neck pain  , yet interactions among these risk factors remain unclear . The purpose of this study was to compare the effects of mentally challenging computer work performed with and without exposure to a psychosocial stressor on cervical muscle activity and posture . Changes in cervical posture and electromyography of upper trapezius , cervical extensor , and sternocleidomastoid muscles were compared between a resting seated posture at baseline , a low stress condition with mental concentration , and a high stress condition with mental concentration and psychosocial stress in sixty healthy office workers .  Forward head posture significantly increased with mental concentration compared to baseline , but did not change with further introduction of the stressor . Muscle activity significantly increased from the low stress to high stress condition for both the dominant and non-dominant upper trapezius , with no corresponding change in activity of the cervical extensors or flexors between stress conditions . These findings suggest that upper trapezius muscles are selectively activated by psychosocial stress independent of changes in concentration or posture , which may have implication s for the prevention of stress-related trapezius myalgia in the workplace QUESTIONS Do symptomatic female office workers perform computing tasks with higher cervical postural muscle loads ( in terms of higher amplitudes and less muscular rest ) and more discomfort compared with asymptomatic individuals ? Are these differences in postural muscle loads consistent across bilateral ( typing ) and unilateral ( mousing ) conditions ? DESIGN an experimental case-control study . PARTICIPANTS 18 symptomatic female office workers and 21 asymptomatic female office workers . INTERVENTION Three conditions ( typing , mousing , and type- and -mouse ) were performed in r and om order . OUTCOME MEASURES Muscle load was measured as median amplitude and gap frequency using surface EMG of bilateral cervical erector spinae and upper trapezius . Discomfort was measured using a numerical rating scale . RESULTS The case group demonstrated 4.3 % ( 95 % CI 0.1 to 8.4 ) higher amplitude during typing and 3.5 % ( 95 % CI 0.1 to 6.9 ) higher amplitude during type- and -mouse in the right cervical erector spinae compared with the control group . There was a similar difference between groups in the left cervical erector spinae which also demonstrated a 1.2 gaps/min ( 95 % CI -2.3 to 0.0 ) lower frequency during typing . The case group had significantly higher discomfort during all conditions compared with the control group . The case group demonstrated higher median amplitudes and lower gap frequencies than the control group during bilateral conditions ( typing and type- and -mouse ) compared with unilateral conditions ( mousing ) for both muscle groups . CONCLUSION There was increased amplitude and decreased muscular rest in the cervical erector spinae of office workers performing typing and mousing tasks . These findings may represent a mechanism underlying computer-related musculoskeletal disorders The present study investigated the effect of chronic neck muscle pain ( defined as trapezius myalgia ) on neck/shoulder muscle function during concentric , eccentric and static contraction . Forty-two female office workers with trapezius myalgia ( MYA ) and 20 healthy matched controls ( CON ) participated . Isokinetic ( -60 , 60 and 180 degrees s(-1 ) ) and static maximal voluntary shoulder abductions were performed in a Biodex dynamometer , and electromyography ( EMG ) obtained in the trapezius and deltoideus muscles . Muscle thickness in the trapezius was measured with ultrasound .  Pain and perceived exertion were registered before and after the dynamometer test . The main findings were that shoulder abduction torque ( at -60 and 60 degrees s(-1 ) ) and trapezius EMG amplitude ( at -60 , 0 and 60 degrees s(-1 ) ) were significantly lower in MYA compared with CON ( p<0.001 - 0.05 ) . Deltoideus EMG and trapezius muscle thickness were not significantly different between the groups . While perceived exertion increased in both groups in response to the test ( p<0.0001 ) , pain increased in MYA only ( p<0.0001 ) . In conclusion , having trapezius myalgia was associated with decreased strength capacity and lowered activity of the painful trapezius muscle . The most consistent differences-in terms of both torque and EMG-were found during slow concentric and eccentric contractions . Activity of the synergistic pain free deltoideus muscle was not significantly lower , indicating specific inhibitory feedback of the painful trapezius muscle only . Parallel increase in pain and perceived exertion among MYA were observed in response to the maximal contractions , emphasizing that heavy physical exertion provokes pain increase only in conditions of myalgia 
    Output:
    
agent
Conclusions : Neck pain was not significantly associated with high job dem and s , low skill discretion , low decision authority , or low peer support .
However , when these variables were combined with increased duration of computing tasks , or ergonomic dem and s , they reached significance .
Supervisor support was found to be the only significant buffer capable of preventing these variables reaching significance in female office workers
***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 Systematic review and best evidence synthesis . OBJECTIVES To describe the prevalence and incidence of  neck pain and disability in workers ; to identify risk factors for neck pain in workers ; to propose an etiological diagram ; and to make recommendations for future research . SUMMARY OF BACKGROUND DATA Previous review s of the etiology of neck pain in workers relied on cross-sectional evidence . Recently published cohorts and r and omized trials warrant a re- analysis of this body of research . METHODS We systematic ally search ed Medline for literature published from 1980 - 2006 . Retrieved articles were review ed for relevance . Relevant articles were critically appraised . Articles judged to have adequate internal validity were included in our best evidence synthesis . RESULTS One hundred and nine papers on the burden and determinants of neck pain in workers were scientifically admissible . The annual prevalence of neck pain varied from 27.1 % in Norway to 47.8 % in Québec , Canada . Each year , between 11 % and 14.1 % of workers were limited in their activities because of neck pain . Risk factors associated with neck pain in workers include age , previous musculoskeletal pain , high quantitative job dem and s , low social support at work , job insecurity , low physical capacity , poor computer workstation design and work posture , sedentary work position , repetitive work and precision work . We found preliminary evidence that gender , occupation , headaches , emotional problems , smoking , poor job satisfaction , awkward work postures , poor physical work environment , and workers ' ethnicity may be associated with neck pain . There is evidence that interventions aim ed at modifying workstations and worker posture are not effective in reducing the incidence of neck pain in workers . CONCLUSION Neck disorders are a significant source of pain and activity limitations in workers . Most neck pain results from complex relationships between individual and workplace risk factors . No prevention strategies have been shown to reduce the incidence of neck pain in workers Neck pain is more prevalent in office workers than in the general community . To date , findings from prospect i ve studies that investigated causal relationships between putative risk factors and the onset of neck pain in this population have been limited by high loss to follow-up . The aim of this research was to prospect ively evaluate a range of risk factors for neck pain in office workers , using vali date d and reliable objective measures as well as attain an estimate of 1-year incidence . We assembled a cohort of 53 office workers without neck pain and  measured individual , physical , workplace and psychological factors at  baseline . We followed participants for 1 year to measure the incidence of neck pain . We achieved 100 % participant follow-up . Cox regression analysis was applied to examine the relationship between the putative risk factors and the cumulative incidence of neck pain . The 1-year incidence proportion of  neck pain in Australian office workers was estimated in this study to be 0.49 ( 95 % CI 0.36–0.62 ) . Predictors of neck pain with moderate to large effect sizes were female gender ( HR : 3.07 ; 95 % CI : 1.18–7.99 ) and high psychological stress ( HR : 1.64 ; 95 % CI : 0.66–4.07 ) . Protective factors included increased mobility of the cervical spine ( HR : 0.44 ; 95 % CI : 0.19–1.05 ) and frequent exercise ( HR : 0.64 ; 95 % CI : 0.27–1.51 ) . These results reveal that neck pain is common in Australian office workers and that there are risk factors that are potentially modifiable Objectives Complaints of the arms , neck , and shoulders in general and computer-related disorders in particular affect many office workers in economically developed countries . However , with the increased use of computer systems in developing countries , the associated musculoskeletal symptoms and risk factors are yet to be investigated . The study investigates the relationship between work-related physical and psychosocial characteristics and symptoms of the arms , neck , and shoulders in an African economically developed worksite . Methods A prospect i ve cohort study with 1-year follow-up was conducted . Data were used from 250 computer office workers in Khartoum , Sudan . Data were collected using the Arabic version of the Maastricht Upper Extremity Question naire . Prevalence rates for symptoms were calculated and the categories of risk factors being evaluated consisted of physical , psychological , and individual risk factors . Multivariable logistic regression analysis was used to identify risk factors associated with complaints that were expressed as odds ratios ( ORs ) with 95 % confidence intervals ( CIs ) . Results The 1-year follow-up prevalence rate was 0.63 ( 95 % CI : 0.58 - 0.70 ) for neck symptoms , 0.56 ( 95 % CI : 0.45 - 0.66 ) for shoulder symptoms , and 0.46 ( 95 % CI : 0.42 - 0.59 ) for symptoms of the forearms/h and s. Three main risk factors were significantly associated with the presence of symptoms : ( 1 ) time pressure [ OR : 1.31 ( 1.00 to 1.90 ) P=0.05 ] , ( 2 ) task difficulty [ OR : 1.85 ( 1.73 to 1.99 ) P=0.03 ] , and ( 3 ) previous history of symptoms [ OR : 4.62 ( 2.20 to 9.35 ) P=0.01 ] . Conclusions The targeted office workers in Sudan are reporting symptoms in the neck , shoulders , and forearms . Work-related psychological factors predicted more significantly the presence of symptoms in the targeted population Flaws in the design , conduct , analysis , and reporting of r and omised trials can cause the effect of an intervention to be underestimated or overestimated . The Cochrane Collaboration ’s tool for assessing risk of bias aims to make the process clearer and more The aim of this study is to investigate if there is a change in oxygen saturation and blood flow in the different parts of the trapezius muscle in office workers with and without trapezius myalgia during a st and ardized computer task .  Twenty right-h and ed office workers participated ; ten were recruited based on pain in the trapezius and ten as matching controls . Subjects performed a combination of typing and mousing tasks for 60 min at a st and ardized workstation .  Muscle tissue oxygenation and blood flow data were collected from the upper trapezius ( UT ) , the middle trapezius ( MT ) and the lower trapezius ( LT ) , both on the left and right side at seven moments ( at baseline and every tenth minute during the 1-h typing task ) by use of the oxygen to see device . In all three parts of the trapezius muscle , the oxygen saturation and blood flow decreased significantly over time in a similar pattern ( p < 0.001 ) . Oxygenation of the left and right UT was significantly higher compared to the other muscle parts ( p < 0.001 ) . Oxygen saturation for the MT was significantly lower in the cases compared to the control group ( p = 0.027 ) . Blood flow of the UT on the right side was significantly lower than the blood flow on the left side ( p = 0.026 ) . The main finding of this study was that 1 h of combined workstation tasks result ed in decreased oxygen saturation and blood flow in all three parts of the trapezius muscle . Future research should focus on the influence of intervention strategies on these parameters Non-r and omised studies of the effects of interventions are critical to many areas of healthcare evaluation , but their results may be biased . It is therefore important to underst and and appraise their strengths and weaknesses . We developed ROBINS-I ( “ Risk Of Bias In Non-r and omised Studies - of Interventions ” ) , a new tool for evaluating risk of bias in estimates of the comparative effectiveness ( harm or benefit ) of interventions from studies that did not use r and omisation  to allocate units ( individuals or clusters of individuals ) to comparison groups . The tool will be particularly useful to those undertaking systematic review s that include non-r and omised studies OBJECTIVE In the course of performing systematic review s on the prevalence of low back and neck pain , we required a tool to assess the risk of study bias . Our objectives were to ( 1 ) modify an existing checklist and ( 2 ) test the final tool for interrater agreement . STUDY DESIGN AND SETTING The final tool consists of 10 items addressing four domains of bias plus a summary risk of bias assessment . Two research ers tested the interrater agreement of the tool by independently assessing 54 r and omly selected studies .  Interrater agreement overall and for each individual item was assessed using the proportion of agreement and Kappa statistic . RESULTS Raters found the tool easy to use , and there was high interrater agreement : overall agreement was 91 % and the Kappa statistic was 0.82 ( 95 % confidence interval : 0.76 , 0.86 ) . Agreement was almost perfect for the individual items on the tool and moderate for the summary assessment . CONCLUSION We have addressed a research gap by modifying and testing a tool to assess risk of study bias . Further research may be useful for assessing the applicability of the tool across different conditions Physical and psychosocial stressors in the workplace have been independently associated with the development of  neck pain  , yet interactions among these risk factors remain unclear . The purpose of this study was to compare the effects of mentally challenging computer work performed with and without exposure to a psychosocial stressor on cervical muscle activity and posture . Changes in cervical posture and electromyography of upper trapezius , cervical extensor , and sternocleidomastoid muscles were compared between a resting seated posture at baseline , a low stress condition with mental concentration , and a high stress condition with mental concentration and psychosocial stress in sixty healthy office workers .  Forward head posture significantly increased with mental concentration compared to baseline , but did not change with further introduction of the stressor . Muscle activity significantly increased from the low stress to high stress condition for both the dominant and non-dominant upper trapezius , with no corresponding change in activity of the cervical extensors or flexors between stress conditions . These findings suggest that upper trapezius muscles are selectively activated by psychosocial stress independent of changes in concentration or posture , which may have implication s for the prevention of stress-related trapezius myalgia in the workplace QUESTIONS Do symptomatic female office workers perform computing tasks with higher cervical postural muscle loads ( in terms of higher amplitudes and less muscular rest ) and more discomfort compared with asymptomatic individuals ? Are these differences in postural muscle loads consistent across bilateral ( typing ) and unilateral ( mousing ) conditions ? DESIGN an experimental case-control study . PARTICIPANTS 18 symptomatic female office workers and 21 asymptomatic female office workers . INTERVENTION Three conditions ( typing , mousing , and type- and -mouse ) were performed in r and om order . OUTCOME MEASURES Muscle load was measured as median amplitude and gap frequency using surface EMG of bilateral cervical erector spinae and upper trapezius . Discomfort was measured using a numerical rating scale . RESULTS The case group demonstrated 4.3 % ( 95 % CI 0.1 to 8.4 ) higher amplitude during typing and 3.5 % ( 95 % CI 0.1 to 6.9 ) higher amplitude during type- and -mouse in the right cervical erector spinae compared with the control group . There was a similar difference between groups in the left cervical erector spinae which also demonstrated a 1.2 gaps/min ( 95 % CI -2.3 to 0.0 ) lower frequency during typing . The case group had significantly higher discomfort during all conditions compared with the control group . The case group demonstrated higher median amplitudes and lower gap frequencies than the control group during bilateral conditions ( typing and type- and -mouse ) compared with unilateral conditions ( mousing ) for both muscle groups . CONCLUSION There was increased amplitude and decreased muscular rest in the cervical erector spinae of office workers performing typing and mousing tasks . These findings may represent a mechanism underlying computer-related musculoskeletal disorders The present study investigated the effect of chronic neck muscle pain ( defined as trapezius myalgia ) on neck/shoulder muscle function during concentric , eccentric and static contraction . Forty-two female office workers with trapezius myalgia ( MYA ) and 20 healthy matched controls ( CON ) participated . Isokinetic ( -60 , 60 and 180 degrees s(-1 ) ) and static maximal voluntary shoulder abductions were performed in a Biodex dynamometer , and electromyography ( EMG ) obtained in the trapezius and deltoideus muscles . Muscle thickness in the trapezius was measured with ultrasound .  Pain and perceived exertion were registered before and after the dynamometer test . The main findings were that shoulder abduction torque ( at -60 and 60 degrees s(-1 ) ) and trapezius EMG amplitude ( at -60 , 0 and 60 degrees s(-1 ) ) were significantly lower in MYA compared with CON ( p<0.001 - 0.05 ) . Deltoideus EMG and trapezius muscle thickness were not significantly different between the groups . While perceived exertion increased in both groups in response to the test ( p<0.0001 ) , pain increased in MYA only ( p<0.0001 ) . In conclusion , having trapezius myalgia was associated with decreased strength capacity and lowered activity of the painful trapezius muscle . The most consistent differences-in terms of both torque and EMG-were found during slow concentric and eccentric contractions . Activity of the synergistic pain free deltoideus muscle was not significantly lower , indicating specific inhibitory feedback of the painful trapezius muscle only . Parallel increase in pain and perceived exertion among MYA were observed in response to the maximal contractions , emphasizing that heavy physical exertion provokes pain increase only in conditions of myalgia 
    Output:
    