Table 3. Intervention studies in VDU work.

Study Total initial participantsFollow-up time Study design Intervention Results
Ergonomic improvements and training
Aarås et al., 2001b  -        n=150
-        6 years
-        prospective, parallel group design

-        3 intervention groups (n=50, n=50, n=50)
-        new lighting system
-        new workplaces
-        optometric corrections if needed

in intervention groups reduction of -        visual discomfort
-        shoulder pain
-        neck pain
Nevala-Puranen et al., 2003  -        n=20
-        7 months
-        longitudinal intervention study 

-        2 intervention groups (n=8, n=7) 

-        improvements in ergonomics
-        improvements and advice in ergonomics
reduction of
-        neck, shoulder and elbow pain in both groups
Brisson et al., 1999  -        n=627
-        2 weeks
-        6 months
-        pretest-posttest study 

-        1 intervention group (n=284)
-        1 control group (n=343)


-        ergonomic training program in ergonomic training group improvements
-        in postural stressors and in musculoskeletal disorders (more frequent in workers under 40 years)
Bayeh and Smith, 1999  -        n=80
-        6 months
-        12 months
-        longitudinal intervention study 

-        3 intervention groups (n=32, n=24, n=25)
-        layout changes
-        layout changes and new workstation accessories
-        layout changes, new workstation accessories and new chair

reduction of
-        self-reported discomfort in all 3 groups
Breaks from computer work
Henning et al., 1997  -        two work sites (n=73, n=19)
-        2 and 3 weeks
-        4 and 6 weeks

-        clinical trial

 
-        2 intervention groups (n=73, n=19)
-        frequent reaks -        at the smaller work site (n=19), productivity, eye, leg and foot comfort increased
-        no effect at the major work site (n=73)
Mouse design and arm support
Aarås et al., 2001a  -        n=67 -        6 onths + 6 months  -        prospective, parallel group design 

-        1 intervention group (n=33)

-        1 control group (n=34)

 
-        alternative (Anir-mouse) mouse in use in alternative mouse group reduction of
-        shoulder pain
-        neck pain
-        forearm pain
-        hand and wrist pain

Lintula et al., 2001  -        n=21
-        6 weeks 
-        work site intervention  

-        2 intervention groups (n=7, n=7)

-        1 control croup (n=7) 
-        arm support for the hand operating the mouse (intervention group I)
-        arm support for both hands (intervention group II)
-        no arm supports (control group)

when using arm supports for both hands reduction of
-        wrist extension
-        trapezius load
-        discomfort
Keyboard design and placement
Tittiranonda et al., 1999a  -        n=80
-        6 months
-        randomized, placebo-controlled trial

-        4 treatments groups (n=20, n=20, n=20, n=20)

-        comparison of 4 different keyboards reduction of
-        hand and arm pain when using alternative geometry keyboards
Rempel et al., 1997  -        n=20
-        12 weeks
-        randomized clinical trial 

-        1 intervention group (n=10)

-        1 control group (n=10)

-        different keys-witch design in intervention group reduction of -        hand pain
Dowler et al., 2001  -        n=67 
-        participants used as own controls

-        controlled intervention study 

-        1 intervention group (n=67)
-        reduction of seated work positions by changing the keyboard location -        a lower muscle activity in trapezius muscles when keyboard was tilted downwards
Screen
Psihogios et al., 2001  -        n=20   -        clinical trial 

-        2 intervention groups (n=10, n=10)
-        2 control persons in both groups 

-        changes in screen location -        preferred screen location generally corresponded to the location in which less neck discomfort was reported