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 ? ”
Effect of Four Computer Keyboards in Computer Users with Upper Extremity Musculoskeletal Disorders
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
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 ? ”