Levels of evidence for interventions associated with positive effects were : Moderate evidence for arm supports ; and Limited evidence for ergonomics training plus workstation adjustments , new chair and rest breaks .
Levels of evidence for interventions associated with “ no effect ” were : Strong evidence for workstation adjustment alone ; Moderate evidence for biofeedback training and job stress management training ; and Limited evidence for cognitive behavioral training .
No interventions were associated with “ negative effects ” .
Conclusion It is difficult to make strong evidence d-based recommendations about what practitioners should do to prevent or manage upper extremity MSDs .
There is a paucity of high quality OHS interventions evaluating upper extremity MSDs and none focused on traumatic injury outcomes or workplace m and ated pre-placement screening exams .
Background Little is known about the most effective occupational health and safety ( OHS ) interventions to reduce  upper extremity musculoskeletal disorders ( MSDs ) and injuries .
Methods A systematic review used a best evidence synthesis approach to address the question : “ do occupational health and safety interventions have an effect on upper extremity musculoskeletal symptoms , signs , disorders , injuries , cl aims and lost time ? ”
A randomised controlled trial evaluating an alternative mouse and forearm support on upper body discomfort and musculoskeletal disorders among engineers
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
Levels of evidence for interventions associated with positive effects were : Moderate evidence for arm supports ; and Limited evidence for ergonomics training plus workstation adjustments , new chair and rest breaks .
Levels of evidence for interventions associated with “ no effect ” were : Strong evidence for workstation adjustment alone ; Moderate evidence for biofeedback training and job stress management training ; and Limited evidence for cognitive behavioral training .
No interventions were associated with “ negative effects ” .
Conclusion It is difficult to make strong evidence d-based recommendations about what practitioners should do to prevent or manage upper extremity MSDs .
There is a paucity of high quality OHS interventions evaluating upper extremity MSDs and none focused on traumatic injury outcomes or workplace m and ated pre-placement screening exams .
Background Little is known about the most effective occupational health and safety ( OHS ) interventions to reduce  upper extremity musculoskeletal disorders ( MSDs ) and injuries .
Methods A systematic review used a best evidence synthesis approach to address the question : “ do occupational health and safety interventions have an effect on upper extremity musculoskeletal symptoms , signs , disorders , injuries , cl aims and lost time ? ”