Moving Away From the Traditional Desktop Computer Workstations

Statement of Problem: Office computer workers have elevated risks of adverse health outcome such as musculoskeletal disorders (MSDs) associated with computer work. Although they now have many alternatives, these modern computer workstations and associated technologies require new guidelines and recommendations for proper practice. We see this as an opportunity to improve current and future computer workstation designs through an ergonomics approach by improving users’ upper extremity biomechanics while interacting with these modern technologies. Method: The dissertation first utilized a psychophysical protocol to compare users’ self-selected set ups for sitting and standing computer workstations. Users’ biomechanics and perceived comfort across different computer tasks for the two workstations are then compared. Subsequently, a hand mapping technique was developed to evaluate effects of computer pointing devices on users’ hand posture and associated forearm muscle effort using 3-D motion analysis and surface electromyography. To improve mobile device ergonomics, we investigated tablet users’ biomechanical load, comfort level and performance while performing swipe actions at different tablet locations. Results: Different selected computer workstation set ups were found for sitting and standing. Compared to sitting, users while standing kept workstation components closer to their sternum and adopted a more neutral shoulder posture while working. However, users had greater wrist extension and started reporting more low back discomfort after 45 minutes. While investigating different computer pointing devices, we found device affordance associated with significantly different hand posture and forearm muscle load. Devices that required less holding and were centrally placed associated with more neutral shoulder and hand postures, with significantly less forearm muscle load. For tablet interface, swipe locations closer to the palm had significantly smaller forearm muscle load and more neutral posture across wrist and thumb joints. Conclusion: Through empirical results described in the dissertation, we demonstrated how users’ upper extremity biomechanics can provide insights into the complex interactions between users and modern computer workstations, both as a whole and with specific components. For technology innovation, ergonomics concepts and methodologies can be used to design future generation technologies that fit users’ physical capabilities to reduce MSDs risk while promoting performance.