title: Supplementary breaks and stretching exercises for data entry operators: a follow-up field study. Stay@Work: Participatory Ergonomics to prevent low back and neck pain among workers: design of a randomised controlled trial to evaluate the (cost-)effectiveness Orchard Evaluation of Ergonomically Modified Apple Bucket A field study of supplementary rest breaks for data-entry operators Predictors of Persistent Elbow Tendonitis Among Auto Assembly Workers Effectiveness of a feedback signal in a computer mouse on upper extremity musculoskeletal symptoms: a randomised controlled trial with an 8-month follow-up A randomised controlled trial evaluating the effects of two workstation interventions on upper body pain and incident musculoskeletal disorders among computer operators A comprehensive work injury prevention program with clerical and office workers: Phase II. Evaluation of Two Preventive Interventions for Reducing Musculoskeletal Complaints in Operators of Video Display Terminals A randomised controlled trial of postural interventions for prevention of musculoskeletal symptoms among computer users A test of two training interventions to prevent work-related musculoskeletal disorders of the upper extremity. The effect of forearm support on musculoskeletal discomfort during call centre work. Effect of an intervention addressing working technique on the biomechanical load of the neck and shoulders among hairdressers. Can a New Behaviorally Oriented Training Process to Improve Lifting Technique Prevent Occupationally Related Back Injuries Due to Lifting? Computer terminal work and the benefit of microbreaks. A randomised controlled trial on whether a participatory ergonomics intervention could prevent musculoskeletal disorders A controlled trial of an educational program to prevent low back injuries. Effects of an ergonomic training program on workers with video display units. A randomised controlled trial evaluating an alternative mouse and forearm support on upper body discomfort and musculoskeletal disorders among engineers Effect of Four Computer Keyboards in Computer Users with Upper Extremity Musculoskeletal Disorders Job task and psychosocial risk factors for work-related musculoskeletal disorders among newspaper employees. A Randomized Controlled Trial to Prevent Patient Lift and Transfer Injuries of Health Care Workers Effects of an active ergonomics training program on risk exposure, worker beliefs, and symptoms in computer users. Effects of ergonomic intervention in work with video display units. A Randomized Controlled Trial Evaluating the Effects of New Task Chairs on Shoulder and Neck Pain Among Sewing Machine Operators: The Los Angeles Garment Study Musculoskeletal, visual and psychosocial stress in VDU operators before and after multidisciplinary ergonomic interventions. Effects of Ergorest® Arm Supports on Muscle Strain and Wrist Positions During the Use of the Mouse and Keyboard in Work With Visual Display Units: A Work Site Intervention Rest break interventions in stoop labor tasks. Health-related effects of worksite interventions involving physical exercise and reduced workhours. A randomized controlled trial evaluating an alternative mouse or forearm support on change in median and ulnar nerve motor latency at the wrist.
abstract: BACKGROUND This study exp and ed previous NIOSH-IRS research examining the effects of rest breaks and stretching exercises on symptoms and performance in data -entry workers . METHODS All workers spent 4 weeks with conventional breaks ( two 15 min breaks per day ) and 4 weeks with supplementary breaks ( two 15 min breaks plus four 5 min breaks per day ) . One-half were assigned at r and om to a group instructed to perform brief stretching exercises during breaks . The remainder comprised the " no stretching " ( control ) group . RESULTS 51 workers ( stretch group n = 21 ; no stretch group n = 30 ) completed the study symptom question naires . Discomfort and eyestrain were significantly lower with supplementary breaks , and supplementary breaks attenuated accumulation of discomfort and eyestrain during work sessions . Data -entry speed was significantly faster with supplementary breaks so that work output was maintained , despite replacing 20 min of work time with break time . In the stretch group , workers reported  stretching  during only 25 % of conventional breaks and 39 % of supplementary breaks , and no significant effects of stretching on discomfort or performance were observed . CONCLUSIONS These results provide further converging evidence that supplementary breaks reliably minimize discomfort and eyestrain without impairing productivity . Low compliance in performing stretches prevented valid assessment of stretching effects . Further research on stretching exercises and exercise compliance is warranted Background Low back pain ( LBP ) and neck pain ( NP ) are a major public health problem with considerable costs for individuals , companies and society . Therefore , prevention is imperative . The Stay@Work study investigates the (cost-)effectiveness of Participatory Ergonomics ( PE ) to prevent LBP and NP among workers . Methods In a r and omised controlled trial ( RCT ) , a total of 5,759 workers working at 36 departments of four companies is expected to participate in the study at baseline . The departments consisting of about 150 workers are pre-stratified and r and omised . The control departments receive usual practice and the intervention departments receive PE . Within each intervention department a working group is formed including eight workers , a representative of the management , and an occupational health and safety coordinator . During a one day meeting , the working group follows the steps of PE in which the most important risk factors for LBP and NP , and the most adequate ergonomic measures are identified on the basis of group consensus . The implementation of ergonomic measures at the department is performed by the working group . To improve the implementation process , so-called ' ergocoaches ' are trained . The primary outcome measure is an episode of LBP and NP . Secondary outcome measures are actual use of ergonomic measures , physical workload , psychosocial workload , intensity of pain , general health status , sick leave , and work productivity . The cost-effectiveness analysis is performed from the societal and company perspective . Outcome measures are assessed using question naires at baseline and after 6 and 12 months . Data on the primary outcome as well as on intensity of pain , sick leave , work productivity , and health care costs are collected every 3 months . Discussion Prevention of LBP and NP is beneficial for workers , employers , and society . If the intervention is proven (cost-)effective , the intervention can have a major impact on LBP and NP prevention and , thereby , on work disability prevention . Results are expected in 2010.Trial registration IS RCT Abstract Background : While preliminary laboratory tests indicate that a hip belt reduces the load on the back , neck and shoulders associated with musculoskeletal strain , an orchard trial is needed to more realistically assess both effectiveness and acceptability . Objective : to evaluate the hip belt 's effectiveness in three areas : worker acceptance , worker productivity , and one-day muscle fatigue of the back and shoulder . Methods : Ninety-six New York apple harvest workers were r and omly assigned to use the intervention hip belt or placebo belt for one week . In a second week all workers switched conditions . Subjects were interviewed at the end of each week to ascertain intervention acceptance . Employer records were review ed to determine bushels picked per day . Subjects also underwent muscle fatigue testing at the beginning and again at the end of one workday during each week . Results : Ninety-one percent of the subjects favored the intervention hip belt . Use of the intervention did not appreciably slow picking speed ( bushels per hour ) as compared to placebo ( 8.8 bu/ hr vs. 8.89 bu/hr ) . Both were significantly faster than the regular equipment condition ( 8.13 bu/hr ) . No significant differences in one-day muscle fatigue were found with intervention use . Conclusions : The belt was acceptable to the workers and did not hinder productivity . However , the anticipated ergonomic benefits were not demonstrable using one-day strength testing This study examined the effects of supplementary rest breaks on musculoskeletal discomfort , eyestrain , mood , and performance in data -entry workers . Two rest break schedules were compared in a within-subjects design . Workers alternated between a ‘ conventional ’ and a ‘ supplementary ’ schedule in 4-week intervals . The conventional schedule contained a 15-min break during the first half of the work shift and a 15-min break during the second half of the shift . The supplementary schedule contained the same two 15-min breaks , and a 5-min break during each hour which otherwise did not contain a break , for a total of 20 extra minutes of break time . Results are based on data from 42 workers . They indicated that discomfort in several areas of the body , and eyestrain , were significantly lower under the supplementary than under the conventional schedule . While symptoms increased from pre- to post-work periods under both schedules , the magnitude of the increases was significantly less under the supplementary schedule . In addition , increases in discomfort of the right forearm , wrist and h and over the course of the work week under the conventional schedule were eliminated under the supplementary schedule . These beneficial effects were obtained without reductions in data -entry performance Introduction : Lateral and medial epicondylitis associated with work activity is a common upper extremity musculoskeletal disorder with a prevalence of 4–30 % depending upon the work setting and diagnostic criteria . The influence of treatment , ergonomic factors , medical history , psychosocial variables , and aging on the improvement of symptoms has not been well defined . Methods : This was a prospect i ve cohort study of a cohort of 45 workers with active elbow tendonitis for an average of 13 months .  Complete resolution of symptoms was the defined outcome measure . Results : The predictive factors for persistent elbow tendonitis included older age ( OR = 1.1 , 95 % CI : 0.99 , 1.33 ) , higher h and repetition level for their job(s ) ( OR = 2.5 , 95 % CI : 1.00 , 6.25 ) , more deviation from a neutral wrist position during the work activity ( OR = 2.0 , 95 % CI : 0.80 , 5.56 ) , and lower perceived decision authority on the job ( OR = 0.9 , 95 % CI : 0.79 , 0.98 ) . Other ergonomic , psychosocial , and electrophysiologic measures were not predictive . The models had relatively high sensitivity and specificity . Treatment effects could not be evaluated due to incomplete data available . Conclusions : Older workers with jobs requiring more repetition and awkward wrist postures , and less decision authority were less likely to have resolution of their elbow tendonitis . Implication s : Workers at highest risk for persistent elbow tendonitis should be placed at jobs with lower repetition levels and that use more neutral wrist postures . Effective interventions must address both the ergonomic and psychosocial risk factors in a multifaceted approach to this problem Objectives : To study the effectiveness of using a computer mouse with a feedback signal for upper extremity musculoskeletal symptoms in office workers . Methods : A r and omised controlled trial with 8 months of follow-up was carried out . The intervention consisted of a computer mouse with a feedback signal . In total , 354 subjects were allocated to the intervention group or the  control group . Measurements were performed with electronic question naires at baseline , after 4 months and after 8 months . Outcome variables were the prevalence and incidence of upper extremity musculoskeletal symptoms and disability in the upper extremities . The intervention process was evaluated by software registration . Results : The use of the mouse with a feedback signal result ed in a significant decrease in duration of mouse usage over time . No differences were found in the number of mouse usage rest breaks . No differences were found in the prevalence ( p = 0.29 ) or incidence ( p = 0.832 ) of upper extremity musculoskeletal symptoms between the groups 8 months after baseline . The prevalence decreased from 49 % at baseline to 44 % after 8 months in the control group , while it remained at 36 % in the intervention group . The incidence was 21 % in the control group and 22 % in the intervention group . Among the population with upper extremity musculoskeletal symptoms at baseline , the risk of experiencing symptoms after 8 months did not differ between the groups ( p = 0.49 ) . Minor disability was found in both groups . In the intervention group , a lower level of physical disability over time was reported than in the control group ( p = 0.02 ) . Conclusions : A feedback signal computer mouse does not affect the prevalence and incidence of upper extremity musculoskeletal symptoms , but it does lower disability scores . Given the high prevalence , study ing preventive interventions for upper extremity musculoskeletal symptoms is of high importance . Trial registration number : IS RCT N13222474 Background : Call centre work with computers is associated with increased rates of upper body pain and musculoskeletal disorders . Methods : This one year , r and omised controlled intervention trial evaluated the effects of a wide forearm support surface and a trackball on upper body pain severity and incident musculoskeletal disorders among 182 call centre operators at a large healthcare company . Participants were r and omised to receive ( 1  ) ergonomics training only , ( 2 ) training plus a trackball , ( 3 ) training plus a forearm support , or ( 4 ) training plus a trackball and forearm support . Outcome measures were weekly pain severity scores and diagnosis of incident musculoskeletal disorder in the upper extremities or the neck/shoulder region based on physical examination performed by a physician blinded to intervention . Analyses using Cox proportional hazard models and linear regression models adjusted for demographic factors , baseline pain levels , and psychosocial job factors . Results : Post-intervention , 63 participants were diagnosed with one or more incident musculoskeletal disorders  . Hazard rate ratios showed a protective effect of the armboard for neck/shoulder disorders ( HR = 0.49 , 95 % CI 0.24 to 0.97 ) after adjusting for baseline pain levels and demographic and psychosocial factors . The armboard also significantly reduced neck/shoulder pain ( p = 0.01 ) and right upper extremity pain ( p = 0.002 ) in comparison to the control group . A return-on-investment model predicted a full return of armboard and installation costs within 10.6 months . Conclusion : Providing a large forearm support combined with ergonomic training is an effective intervention to prevent upper body musculoskeletal disorders and reduce upper body pain associated with computer work among call centre employees Sixteen full-time clerical and office workers participated in this prospect i ve parallel-r and omized trial . Intervention consisted of four hours of individualized training through a multi-faceted injury prevention program . In Phase I , musculoskeletal symptoms , stress , and energy levels were measured before and after intervention . Differences between Group A ( intervention ) and Group B ( control ) were described ; pre to post differences between members within each group were also described . In Phase II , there were a greater number of statistically and clinical ly relevant differences within Group A at week 16 ( eleven weeks following intervention ) than at week five ( immediately post-intervention ) . The eyes , neck , shoulder , elbow-forearm , and wrist-h and were impacted most positively by intervention , however , the frequency and intensity of headaches increased . Stress and energy level differences were minimal . Group B workers received intervention during weeks 18 - 21 . Differences in average measures from pre to immediately post-intervention were greater within Group B than Group A. Both groups reported fewer sick days during the month of intervention than during pre and post-intervention months Background and Purpose The purpose of this study was to evaluate the efficacy of a preventive ergonomic intervention , which was provided by physical therapists , on spinal and upper-extremity work-related posture and symptom complaints of workers who use video display terminals ( VDT ) . Subjects Two hundred employees who spent at least 20 hours per week at a VDT were r and omly divided into 2 groups . Group E received the ergonomic intervention and an informative brochure , and group I received only the brochure . Methods Both groups were evaluated at the beginning of the study and at a follow-up 5 months later . The following tools were used : a pain drawing and the Rapid Entire Body Assessment ( REBA ) method to assess spinal and upper-extremity work-related posture . Results Group E had a lower REBA score and reduced lower back , neck , and shoulder symptoms compared with group I. Discussion and Conclusion The results suggest that a personalized preventive ergonomic intervention can improve spinal and upper-extremity work-related posture and musculoskeletal symptoms for workers who use VDTs Aims : To examine the effect of two workstation and postural interventions on the incidence of  musculoskeletal symptoms among computer users . Methods : R and omised controlled trial of two distinct workstation and postural interventions ( an alternate intervention and a conventional intervention ) among 376 persons using computer keyboards for more than 15 hours per week . The incidence of neck/shoulder symptoms and h and /arm symptoms during six months of follow up among individuals in the intervention groups was compared to the incidence in computer users who did not receive an intervention ( comparison group ) . For individuals in the intervention groups , study staff adjusted workstations , where possible , and trained individuals to assume the intervention postures . Individuals reported musculoskeletal symptoms in a weekly diary . Participants who reported discomfort intensity of 6 or greater on a 0–10 visual analogue scale or who reported musculoskeletal symptoms requiring use of analgesic medication were considered symptomatic . Results : There were no significant differences in the incidence of musculoskeletal symptoms among the three intervention groups . Twenty two ( 18.5 % ) participants in the alternate intervention group , 25 ( 20.2 % ) in the conventional intervention group , and 25 ( 21.7 % ) in the comparison group developed incident arm or h and symptoms . Thirty eight ( 33.3 % ) participants in the alternate intervention group , 36 ( 31.0 % ) in the conventional intervention group , and 33 ( 30.3 % ) in the comparison group developed incident neck or shoulder symptoms . Compliance with all components of the intervention was attained for only 25–38 % of individuals , due mainly to the inflexibility of workstation configurations . Conclusions : This study provides evidence that two specific workplace postural interventions are unlikely to reduce the risk of upper extremity musculoskeletal symptoms among computer users We investigated , on behalf of a large electronics manufacturer , two types of worker training interventions  for their efficacy in preventing unnecessary muscle tension and the symptoms of work-related musculoskeletal disorders . The first intervention , Muscle Learning Therapy ( MLT ) , used electromyographic ( sEMG ) feedback and operant conditioning to decrease muscle tension during complex work tasks . The second intervention used adult learning and cognitive behavioral techniques in small group discussion to advance the worker 's capabilities for symptom and stress management and problem-solving . Workers were r and omly assigned to a control group or one of the two treatment conditions . Prior to training , baseline data were collected using symptom diaries and sEMG recordings of the trapezius and forearm muscles of the left and right arms . The training interventions were conducted for 6 weeks with reinforcement training provided at 18 and 32 weeks post-baseline . Follow-up data were collected after the initial 6-week training period and at 32 weeks , prior to the reinforcement training . Symptom outcomes demonstrated significant differences at 6 weeks , increasing in severity for the control group and declining modestly for the educational group , with little change for the MLT group . These differences were not maintained at further follow-up . The MLT group was consistently effective in reducing muscle tension in the trapezius areas after 6 and 32 weeks , and was partially effective for the forearms . Further testing is recommended of these training interventions , especially with the inclusion of strategic , periodic reinforcement of the worker 's learning Using a computer keyboard with the forearms unsupported has been proposed as a causal factor for  neck/shoulder and arm/h and diagnoses . Recent laboratory and field studies have demonstrated that forearm support might be preferable to working in the traditional " floating " posture . The aim of this study was to determine whether providing forearm support when using a normal computer workstation would decrease musculoskeletal discomfort in intensive computer users in a call centre . A r and omised controlled study ( n = 59 ) , of 6 weeks duration was conducted . Thirty participants ( Group 1 ) were allocated to forearm support using the desk surface with the remainder ( Group 2 ) acting as a control group . At 6 weeks , the control group was also set up with forearm support . Both groups were then monitored for another 6 weeks . Question naires were used at 1 , 6 and 12 weeks to obtain information about discomfort , workstation setup , working posture and comfort .  Nine participants ( Group 1 n = 6 , Group 2 n = 3 ) withdrew within a week of commencing forearm support either due to discomfort or difficulty in maintaining the posture . At 6 weeks , the group using forearm support generated significantly fewer reports of discomfort in the neck and back , although the difference between the groups was not statistically significant . At 12 weeks , there were fewer reports of neck , back and wrist discomfort when preintervention discomfort was compared with post intervention discomfort . These findings indicate that for the majority of users , forearm support may be preferable to the " floating " posture implicit in current guidelines for computer workstation setup The purpose of this study was to describe , and analyse the effect of an intervention on , the biomechanical workload in the neck and shoulder region of female hairdressers . Arm elevation was measured by inclinometers and muscular load of m. trapezius by electromyography . The intervention comprised working technique recommendations , e.g. to work with less elevated arms and more relaxed muscles . The subjects were r and omised between two different intensity levels of the intervention , one with written information only and the other with additional personal follow-up . The effect of the intervention was evaluated after 1 - 2 months . The hairdressers worked with their arms elevated 60 degrees or more for approximately 13 % of the total working time and 16 % during the specific hairdressing tasks . The intervention group including personal follow-up instructions had a reduction in workload from 4.0 % to 2.5 % of hairdressing time with highly elevated right upper arm , i.e. above 90 degrees . No effect was detected on muscular load or neck and shoulder symptoms after the intervention Study Design . A prospect i ve r and omized control trial . Objective . To determine the degree to which a new behavior-based lift training program ( LiftTrainer ™ ; Ascension Technology , Burlington , VT ) could reduce the incidence of  low back disorder in distribution center jobs that require repetitive lifting . Summary of Background Data . Most studies show programs aim ed at training lifting techniques to be ineffective in preventing low back disorders , which may be due to their conceptual rather than behavioral learning approach . Methods . A total of 2144 employees in 19 distribution centers were r and omized into either the LiftTrainer ™ program or a video control group . In the LiftTrainer ™ program , participants were individually trained in up to 5 , 30-minute sessions while instrumented with motion capture sensors to quantify the L5/S1 moments . Twelve months following the initial training , injury data were obtained from company records . Results . Survival analyses ( Kaplan-Meier ) indicated that there was no difference in injury rates between the 2 training groups . Likewise , there was no difference in the turnover rates . However , those with a low ( < 30 Nm ) average twisting moment at the end of the first session experienced a significantly ( P < 0.005 ) lower rate of low back disorder than controls . Conclusions . While overall the LiftTrainer ™ program was not effective , those with twisting moments below 30 Nm reported fewer injuries , suggesting a shift in focus for “ safe ” lifting programs Microbreaks are scheduled rest breaks taken to prevent the onset or progression of cumulative trauma disorders in the computerized workstation environment . The authors examined the benefit of microbreaks by investigating myoelectric signal ( MES ) behavior , perceived discomfort , and worker productivity while individuals performed their usual keying work . Participants were r and omly assigned to one of three experimental groups . Each participant provided data from working sessions where they took no breaks , and from working sessions where they took breaks according to their group assignment : microbreaks at their own discretion ( control ) , microbreaks at 20 min intervals , and microbreaks at 40 min intervals . Four main muscle areas were studied : the cervical extensors , the lumbar erector spinae , the upper trapezius/supraspinatus , and the wrist and finger extensors . The authors have previously shown that when computer workers remained seated at their workstation , the muscles performing sustained postural contractions displayed a cyclic trend in the mean frequency ( MNF ) of the MES ( McLean et al. , J. Electrophysiol . Kinesiol . 10 ( 1 ) ( 2000 ) 33 ) . The data provided evidence ( p < 0.05 ) that all microbreak protocol s were associated with a higher frequency of MNF cycling at the wrist extensors , at the neck when microbreaks were taken by the control and 40 min protocol groups , and at the back when breaks were taken by the 20 and 40 min protocol groups . No significant change in the frequency of MNF cycling was noted at the shoulder . It was determined ( p < 0.05 ) that microbreaks had a positive effect on reducing discomfort in all areas studied during computer terminal work , particularly when breaks were taken at 20 min intervals . Finally , microbreaks showed no evidence of a detrimental effect on worker productivity . The underlying cause of MNF cycling , and its relationship to the development of discomfort or cumulative trauma disorders remains to be determined Objectives : To examine the efficacy of a participatory ergonomics intervention in preventing musculoskeletal disorders among kitchen workers .  Participatory ergonomics is commonly recommended to reduce musculoskeletal disorders , but evidence for its effectiveness is sparse . Methods : A cluster r and omised controlled trial among the 504 workers of 119 kitchens in Finl and was conducted during 2002–2005 . Kitchens were r and omised to an intervention ( n = 59 ) and control ( n = 60 ) group . The duration of the intervention that guided the workers to identify strenuous work tasks and to seek solutions for decreasing physical and mental workload , was 11 to 14 months . In total , 402 ergonomic changes were implemented . The main outcome measures were the occurrence of and trouble caused by musculoskeletal pain in seven anatomical sites , local fatigue after work , and sick leave due to musculoskeletal disorders . Individual level data were collected by a question naire at baseline and every 3 months during the intervention and 1-year follow-up period . All response rates exceeded 92 % . Results : No systematic differences in any outcome variable were found between the intervention and control groups during the intervention or during the 1-year follow-up . Conclusions : The intervention did not reduce perceived physical work load and no evidence was found for the efficacy of the intervention in preventing musculoskeletal disorders among kitchen workers . It may be that a more comprehensive re design of work organisation and processes is needed , taking more account of workers ’ physical and mental re sources BACKGROUND Low back injuries are common and costly , accounting for 15 to 25 percent of injuries covered by workers ' compensation and 30 to 40 percent of the payments made under that program . The high costs of injury , the lack of effective treatment . and the evidence that there are behavioral risk factors have led to widespread use of employee education programs that teach safe lifting and h and ling . The effectiveness of those programs , however , has received little rigorous evaluation . METHODS We evaluated an educational program design ed to prevent low back injury in a r and omized , controlled trial involving about 4000 postal workers . The program , similar to that in wide use in so-called back schools , was taught by experienced physical therapists . Work units of workers and supervisors were trained in a two-session back school ( three hours of training ) , followed by three to four reinforcement sessions over the succeeding few years . Injured subjects ( from both the intervention and the control groups ) were r and omized a second time to receive either training or no training after their return to work . RESULTS Physical therapists trained 2534 postal workers and 134 supervisors . Over 5.5 years of follow-up , 360 workers reported low back injuries , for a rate of 21.2 injuries per 1000 worker-years of risk . The median time off from work per injury was 14 days ( range , 0 to 1717 ) ; the median cost was $ 204 ( range , zero to $ 190,380 ) . After their return to work , 75 workers were injured again . Our comparison of the intervention and control groups found that the education program did not reduce the rate of low back injury , the median cost per injury , the time off from work per injury , the rate of related musculoskeletal injuries , or the rate of repeated injury after return to work ; only the subjects ' knowledge of safe behavior was increased by the training . CONCLUSIONS A large-scale , r and omized , controlled trial of an educational program to prevent work-associated low back injury found no long-term benefits associated with training OBJECTIVES This study evaluated the effect of an ergonomic training program on workstation changes and on the prevalence of  musculoskeletal disorders among video display unit ( VDU ) users at a large university . METHODS A pretest-posttest design with a reference group was used with r and om allocation of administrative and geographic units . In each group , the measurements involved direct observation of the workstations , a self-administered question naire , and a physical examination . The measurements were performed 2 weeks before and 6 months after the training in parallel in both groups . The study population was composed of 627 workers ( 81 % of those eligible ) . RESULTS The prevalence of all 3 of the postural stressors evaluated decreased in the experimental group after the training . In the reference group , 2 of the 3 stressors decreased in frequency but to a less extent . Some of these beneficial changes were more frequent in workers under 40 years of age . The prevalence of musculoskeletal disorders decreased among the workers under 40 years of age in the experimental group , from 29 % to 13 % determined by question naire and from 19 % to 3 % determined by physical examination . In other groups , there was no significant change in the prevalence of musculoskeletal disorders . CONCLUSIONS Improvements in postural stressors occurred more frequently in the experimental group , and these beneficial changes tended to be more frequent in workers under 40 years of age . Improvements in musculoskeletal disorders occurred in the experimental group among the workers under 40 years of age Objectives : The aim of this intervention study was to determine the effects of an alternative mouse and /or a forearm support board on the change in upper body discomfort scores and the development of incident musculoskeletal disorders . Methods : This r and omised controlled intervention trial followed 206 engineers for one year . Participants were r and omised to receive ( 1 ) a conventional mouse only , ( 2 ) an alternative mouse only , ( 3 ) a forearm support board , or ( 4 ) an alternative mouse plus forearm support board . Outcome measures included weekly upper body discomfort scores and incident musculoskeletal disorders . Results : During the study , 42 participants were diagnosed with an incident musculoskeletal disorder . The group that received the forearm support board experienced a reduction in their right upper extremity discomfort ( beta-coefficient −0.35 , 95 % CI −0.67 to −0.03 ) in comparison to those who did not receive a forearm board . The group that received the alternative mouse had a protective , but non-significant ( p = 0.20 ) , effect on incident cases of right upper extremity musculoskeletal disorders ( HR 0.57 , 95 % CI 0.24 to 1.34 ) and a non-significant reduction in neck/shoulder discomfort ( beta-coefficient −0.23 , 95 % CI −0.056 to 0.10 ) in comparison to those who received a conventional mouse . Conclusions : In engineers who use a computer for more than 20 h per week , a forearm support board may reduce right upper extremity discomfort attributed to computer use Eighty computer users with musculoskeletal disorders participated in a six-month , r and omized , placebo-controlled trial evaluating the effects of four computer keyboards on clinical findings , pain severity , functional h and status , and comfort . The alternative geometry keyboards tested were : the Apple Adjustable Keyboard ™ [ kb1 ] , Comfort Keyboard System ™ [ kb2 ] , Microsoft Natural Keyboard ™ [ kb3 ] and placebo . Compared to placebo , kb3 and to a lesser extent kb1 groups demonstrated an improving trend in pain severity and h and function following six months of keyboard use . However , there was no corresponding consistent improvement in clinical findings in the alternative geometry keyboard groups compared to the placebo group . Overall , there was a significant correlation between improvement of pain severity and greater satisfaction with the keyboards . These results provide evidence that keyboard users may experience a reduction in h and pain after several months of use of some alternative geometry keyboards OBJECTIVES A cross-sectional study was conducted to assess the association of upper extremity musculoskeletal disorders and work-related factors among employees using video display terminals at a large metropolitan newspaper . METHODS The study included 1050 r and omly selected workers from four departments . The workers were asked to complete question naires on symptoms , job tasks , and psychosocial and work organization conditions . Musculoskeletal disorders of the upper extremities were defined by frequency , duration , and intensity of symptoms not attributable to acute injury . Data were analyzed with the use of logistic regression . RESULTS A total of 973 workers completed the survey . The one-year period prevalence rate for any musculoskeletal disorder of the upper extremities was 41 % . Neck symptoms ( 26 % ) were the most frequently reported , followed by h and or wrist ( 22 % ) , shoulder ( 17 % ) , and elbow ( 10 % ) symptoms . Greater time working at the video display station was associated with increased h and or wrist symptoms in a dose-response relationship . In addition , variables corresponding to increased work-load dem and s ( eg , increased time working under deadline and increased job pressure ) were associated with increased neck , shoulder , and h and or wrist disorders . Women were more likely to report symptoms in several areas , but this finding may reflect the concentration of women in jobs involving more risk factors . CONCLUSIONS The results suggest a high prevalence of musculoskeletal disorders of the upper extremities among newspaper employees , and they provide additional evidence that increased work load , time pressure , and greater hours of computer use are related to the occurrence of work-related musculoskeletal disorders among these workers , particularly for disorders in the h and or wrist area Study Design . R and omized controlled trial ( RCT ) . Objectives . To compare the effectiveness of training and equipment to reduce musculoskeletal injuries , increase comfort , and reduce physical dem and s on staff performing patient lifts and transfers at a large acute care hospital . Summary of Background Data . Back injury to nursing staff during patient h and ling tasks is a major issue in health care . The value of mechanical assistive devices in reducing injuries to these workers is unclear . Methods . This three-armed RCT consisted of a “ control arm , ” a “ safe lifting ” arm , and a “ no strenuous lifting ” arm .  A medical , surgical , and rehabilitation ward were each r and omly assigned to each arm . Both intervention arms received intensive training in back care , patient assessment , and h and ling techniques . Hence , the “ safe lifting ” arm used improved patient h and ling techniques using manual equipment , whereas the “ no strenuous lifting ” arm aim ed to eliminate manual patient h and ling through use of additional mechanical and other assistive equipment . Results . Frequency of manual patient h and ling tasks was significantly decreased on the “ no strenuous lifting ” arm . Self-perceived work fatigue , back and shoulder pain , safety , and frequency and intensity of physical discomfort associated with patient h and ling tasks were improved on both intervention arms , but staff on the mechanical equipment arm showed greater improvements . Musculoskeletal injury rates were not significantly altered . Conclusions . The “ no strenuous lifting ” program , which combined training with assured availability of mechanical and other assistive patient h and ling equipment , most effectively improved comfort with patient h and ling , decreased staff fatigue , and decreased physical dem and s. The fact that injury rates were not statistically significantly reduced may reflect the less sensitive nature of this indicator compared with the subjective indicators OBJECTIVE The purpose of this study was to evaluate the effectiveness of an active ergonomics training ( AET ) program in computer users . Two constructs from the social-cognitive theory were adopted to provide a more comprehensive assessment of the proximal markers of behavior change . METHOD Eighty-seven symptomatic and asymptomatic employees who worked at a computer for a minimum of 10 hours per week took part in a prospect i ve r and omized controlled study . Subjects participated in a six-hour training intervention at their workplace . Key elements of the AET intervention were skill development in workstation analysis , active participation , and implementation of multiple prevention strategies . RESULTS After receiving AET , risk factor exposure was significantly reduced for participants at higher risk [ F(1,82 ) = 6.42 , p < 0.01 ] . Significant increases in knowledge [ F(1,74 ) = 8.39 , p < 0.01 ] , self-efficacy [ F(1,73 ) = 6.95 , p < 0.01 ] , and outcome expectations [ F(1,75 ) = 8.75 , p < 0.01 ] were found in the intervention group . When the participants were stratified according to the presence of symptoms at baseline , the group with pain that received the AET intervention had significantly less upper back pain intensity ( z = -2.03 , p < 0.05 ) , pain frequency ( z = -2.70 , p < 0.01 ) , and pain duration ( z = -3.25 , p < 0.01 ) post-intervention than the control group with pain . CONCLUSION Results from this study provide evidence that participative training in workstation ergonomics can improve work postures , work practice s , risk factor exposure , and pain OBJECTIVES This study evaluated the effect of an intensive ergonomic approach and education on workstation changes and  musculoskeletal disorders among workers who used a video display unit ( VDU ) . METHODS A r and omized controlled design was used . The subjects ( N=124 ) were allocated into three groups ( intensive ergonomics , ergonomic education , reference ) using stratified r and om sampling . The evaluation involved question naires , a diary of discomfort , measurements of workload , and an ergonomic rating of the workstations . The assessment s were made 2 weeks before the intervention and after 2 and 10 months of follow-up . RESULTS The intensive and training groups showed less musculoskeletal discomfort than the reference group after 2 months of follow-up . Positive effects on discomfort were seen primarily for the shoulder , neck , and upper back areas . No significant differences were found for the strain levels or prevalence of pain . After the intervention the ergonomic level was distinctly higher in the intensive ergonomic group than in the education or reference group . CONCLUSIONS Both the intensive ergonomics approach and education in ergonomics help reduce discomfort in VDU work . In attempts to improve the physical ergonomics of VDU workstations , the best result will be achieved with cooperative planning in which both workers and practitioners are actively involved Study Design . This is a 4-month r and omized controlled trial to evaluate the effect of chair design on neck/shoulder pain  among sewing machine operators . Objective . Determine whether a chair with a curved seat pan leads to improved changes in monthly neck/shoulder pain scores compared with a control intervention . Summary of Background Data . Sewing machine operators experience a high prevalence and severity of neck and shoulder pain in comparison to other working population s probably due to the sustained shoulder abduction and neck and upper back flexion required of the task . An adjustable height task chair that supports a forward sitting posture may reduce these posture-related risk factors and reduce neck/shoulder pain . Material s and Methods . A total of 277 sewing machine operators with neck/shoulder pain were assigned to receive 1 ) miscellaneous items ( control group ) , 2 ) a chair with a flat seat pan plus miscellaneous items , or 3 ) a chair with a curved seat pan plus miscellaneous items . Participants completed a monthly question naire assessing neck/shoulder pain severity . Results . Based on estimates of pain score changes from a repeat- measures linear regression , participants who received the flat seat chair experienced a decline in pain of 0.14 ( 95 % confidence interval , 0.07–0.22 ) points per month compared with those in the control group , while those who received the curved seat experienced a decline of 0.34 ( 95 % confidence interval , 0.28–0.41 ) points per month compared with those in the control group . These estimates did not change after adjustment for potential covariates . Conclusions . These findings demonstrate that an adjustable height task chair with a curved seat pan can reduce neck and shoulder pain severity among sewing machine operators The study has a parallel group design with two intervention groups ( T and S ) and one control group ( C ) of VDU operators . Three serial interventions were carried out in the T and S groups , first a new lighting system , then new workplaces and last an optometric examination and corrections if needed . The new lighting gave significantly increased illuminance levels , increased luminances of the room surfaces and better luminance distribution . The two intervention groups reported significant improvement of the lighting conditions , as well as of the visual conditions and significantly reduced visual discomfort and glare . Significant reduction of headache was found in one of the intervention groups . Optometric corrections reduced the visual discomfort in both the intervention groups . When looking at those given new corrections , a significant reduction was found in the T group and a clear tendency was also found in the S group . The C group reported no improvements for any of these health outcomes . The workplace intervention gave the operator the possibility to support the whole forearm and h and on the table top . Before the intervention there were no significant differences between the three groups regarding shoulder pain and static trapezius electromyographic ( EMG ) load . Two years after the intervention , a significant reduction of shoulder pain was reported in the T and S groups in parallel with a significant reduction in static trapezius load , while no such reduction was found in the C group . At the same time , both static trapezius load and shoulder pain were significantly lower in the T and S groups compared with the C group . Pain in the forearm and h and showed no significant changes in any of the groups during the study period . However , there seem to be a relationship between pain in the forearm and h and and the time the operator used the mouse . The C group reported significantly higher intensity of pain and used the mouse significantly more than the S group The effects of Ergorest ® arm supports on wrist angles and musculoskeletal strain in the neck-shoulder-arm region and electrical activity in the shoulder and arm muscles were studied during typing or the use of the mouse in work with a visual display unit ( VDU ) . Twenty-one women were r and omized into 3 groups ( 1 arm support , 2 arm supports , and control ) . Measurements were carried out before and after the 6-week intervention . The wrist extension of the mouse h and , the muscle activity of the trapezius muscle , and the subjective discomfort ratings indicated that 2 arm supports were better than 1 in work with a mouse . The Ergorest ® arm support alleviates muscle and joint strain in VDU work when used for both arms H and cultivation and harvest of agricultural products constitute strenuous physical tasks . Working with labor-management ergonomics committees in agricultural setting s , the UC Agricultural Ergonomics Research Center ( AERC ) tested an experimental rest and recovery protocol for its impact on symptoms and productivity during two types of work tasks . The experimental condition consisted of adding a 5 min rest break to every working hour in which there was no other scheduled break ( e.g. , lunchtime ) . This result ed in an additional 20 min of rest per workday . We tested the intervention in two trials : Trial one compared workers ( n=66 ) r and omly assigned to an experimental or a control group during the harvest of commercial strawberries . Trial two utilized a cross-over design ( n=16 pairs of workers ) to compare experimental and control conditions while workers inserted bud grafts into young 18 ' ' high citrus trees . For both trials , workers under the experimental condition reported significantly less severe symptoms than workers under control conditions . The order in which the intervention was given , however , appeared to result in variations in productivity . We conclude that the introduction of frequent , brief rest breaks may improve symptoms for workers engaged in strenuous work tasks OBJECTIVES This study examined the health-related effects of two worksite interventions , physical exercise and reduced workhours , on women employed in dentistry . METHODS Six workplaces were r and omized to one of the following three conditions : ( i ) 2.5 hours of weekly , m and atory physical exercise of middle-to-high intensity to be performed during workhours ( N=62 ) , ( ii ) a reduction of full-time weekly workhours from 40 to 37.5 hours ( N=50 ) , and ( iii ) reference . In all , 177 women participated . Biomarkers and self-ratings in question naires were obtained before the intervention ( T ( 1 ) ) , and six ( T ( 2 ) ) and 12 months ( T ( 3 ) ) after the intervention . RESULTS The results showed increased levels of physical activity and exercise in all of the groups , the level of physical exercise being significantly greater in the physical exercise group . Repeated- measures analyses of variance using data from T ( 1 ) and T (3)for biological measures and all three time points for self-ratings produced significant interaction effects for glucose , waist-to-hip ratio , and work ability and clear trends for general symptoms and upper-extremity disorders . Posthoc analyses showed that the results of the health-related measures differed between the interventions , decreased glucose and upper-extremity disorders in the exercise group , and increased high-density lipoprotein and waist-to-hip ratio among those working reduced hours . CONCLUSIONS These results show that the two interventions had small and varied effects on biomarkers and self-reports of different aspects of health among women . It is suggested that interventions involving a modest reduction in workhours seem to be more effective if these hours are used for physical exercise BACKGROUND The purpose of this study was to determine the effects of an alternative mouse and /or a forearm support board on  nerve function at the wrist among engineers . METHODS This r and omized controlled intervention trial followed 206 engineers for 1 year . Distal motor latency ( DML ) at baseline and follow-up was conducted for the median and ulnar nerves at the right wrist . RESULTS One hundred fifty-four subjects agreed to a nerve conduction study at the beginning and end of the study period . Those who received the alternative mouse had a protective effect ( OR = 0.47 , 95 % CI 0.22 - 0.98 ) on change in the right ulnar DML . There was no significant effect on the median nerve DML . The forearm support board had no significant effect on the median or ulnar nerve DML . CONCLUSIONS In engineers who use a computer for more than 20 hr per week , an alternative mouse may have a protective effect for ulnar nerve function at the wrist . No protective effect of a forearm support board was found for the median nerve
target: There was low- to very low- quality evidence that other interventions were not effective in reducing work-related upper limb and neck MSDs in adults .
  We found moderate- quality evidence to suggest that the use of arm support with alternative mouse may reduce the incidence of neck/shoulder MSDs , but not right upper limb MSDs .
  Moreover , we found moderate- quality evidence to suggest that the incidence of neck/shoulder and right upper limb MSDs is not reduced when comparing alternative and conventional mouse with and without arm support .
  However , given there were multiple comparisons made involving a number of interventions and outcomes , high- quality evidence is needed to determine the effectiveness of these interventions clearly .
  While we found very-low- to low- quality evidence to suggest that other ergonomic interventions do not prevent work-related MSDs of the upper limb and neck , this was limited by the paucity and heterogeneity of available studies .
background: BACKGROUND Work-related upper limb and neck musculoskeletal disorders ( MSDs ) are one of the most common occupational disorders around the world .
  Although ergonomic design and training are likely to reduce the risk of workers developing work-related upper limb and neck MSDs , the evidence is unclear .
  OBJECTIVES To assess the effects of workplace ergonomic design or training interventions , or both , for the prevention of work-related upper limb and neck MSDs in adults .