1. Approaches to the Assessment of Physical Exposure in VDT Work

2. Methods of Investigating WMSD and VDT Operators Epidemiologic Issue: How to measure “Exposure” (and Health)? Laboratory Issue:What are relevant measures?

3. Methods of Investigating WMSD and VDT Operators Epidemiologic Approaches Questionnaires Work Sampling Technical Exposure Assessment Surface EMG Posture registration Laboratory Approaches Surface Electromyograms Indwelling Electromyograms

4. VDT Office Environment

5. Work in VDT Office Environment Talk with co-worker Desk work Talk on phone Interactive editing Filing Filling out forms Walk to... Graphic editing Numeric pad entry

6. Physical Exposure for VDT Operators M I-Distal Predictors of Exposure *Job design *Task variety *Workstation dimensions II-Proximal Predictors of Exposure *Wrist Posture * Keystrokes force III- (Internal) Exposure *Muscle activation *Tendon Load

7. Physical Exposure for VDT Operators InternalExternal ExposurePredictors of Exposure Immediate/More Distant/ Proximal Distal Proximal Distal Posture Force Repetitiveness Muscle Force, Activation, Rest, Metabolism Tendon Force, Friction Movement, Nutrition Duration (Median) Nerve Pressure, Contact Stress, Friction, Stretch

8. Physical Exposure for VDT Operators III- Exposure R/L Trapezius static Trapezius gaps R/L Wrist/finger extensor static Wrist/finger extensor gaps Tendon loads/strain Carpal canal pressure O 2 tension Twitch force Ca++ II-Proximal Predictors of Exposure Wrist posture Shoulder posture Neck posture Gaze angle %time sitting % steps walked Hand Activity Level Keystrike force I-Distal Predictors of Exposure Job title Workgroups Task variety # task transitions Workstation dimensions Key depression force Control Psychological demand