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 keyboard keyswitch design on hand pain.
This r and omized clinical trial evaluated the effects of keyboard keyswitch design on computer users with h and paresthesias . Twenty computer users were matched and r and omly assigned to keyboard A ( n = 10 ) or B ( n = 10 ) . The keyboards were of conventional layout and differed in keyswitch design . Various outcome measures were assessed during the 12 weeks of use . Subjects assigned keyboard A experienced a decrease in h and pain between weeks 6 and 12 when compared with keyboard B subjects ( P = 0.05 ) and demonstrated an improvement in the Phalen test time ( right h and , P = 0.006 ; left h and , P = 0.06 ) . Keyboard assignment had no significant effect on change in h and function or median nerve latency . We conclude that use of keyboard A for 12 weeks led to a reduction in h and pain and an improved physical examination finding when compared with keyboard B. There was no corresponding improvement in h and function or median nerve latency
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 ? ”