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 ? ”
The Effect of Alternate Style Keyboards on Severity of Symptoms and Functional Status of Individuals with Work Related Upper Extremity Disorders
There is evidence that performing job tasks involving repetition , vibration , sustained posture or forceful movement may contribute to symptoms of work related upper extremity disorders . Typing is one such activity ; symptoms that develop as a result of this activity can affect performance of work , self-care and leisure occupations . Studies investigating the impact of ergonomic keyboards on symptom reduction are limited , and little research exists regarding the reduction of key activation force as an intervention . Methods : This r and omized , prospect i ve study used a sample of 68 symptomatic workers employed by a single company . One group received a commercially available ergonomic keyboard , a second group used a modified version of the same keyboard design ed to reduce activation force , vibration and key travel . We measured symptoms and clinical signs , functional status , and device satisfaction in both groups over a six-month study period . Results : Between-groups analyses indicated that the groups performed similarly on the outcomes of interest . Repeated-measure analysis identified a reduction of symptoms , an improvement in functional status , preference for and increased satisfaction with the intervention keyboards , and maintenance of typing speed and accuracy for both groups . Conclusions
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 ? ”