The Effect of Adjusting Screen Height and Keyboard Placement on Neck and Back Discomfort, Posture, and Muscle Activities during Laptop Work

ABSTRACT

Laptop work may increase risks of neck and back injuries in the long term due to awkward postures and increased mechanical loads on cervical and lumbar spine. This study was intended to compare the muscle activities and postural changes as well as discomfort of the neck and back resulted from the laptop work in a conventional and adjusted setup. 20 young healthy males performed two 8-min sessions of computer-mouse work and typing in a conventional setup and in an ergonomically adjusted setup during laptop work. In the adjusted setup, the screen height was individually adjusted by a riser and the keyboard was externally connected. The posture of the cervical, thoracic, lumbar spines, and shoulder, as well as electromyographic activity of cervical and lumbar erector spinae, multifidus, upper trapezius and anterior deltoid muscles, were recorded during the first and last 2 min of each computer work session. Having completed the computer work session, furthermore, the participants scored their neck, back, and general discomfort. The very research findings implied that adjusting the screen height and keyboard placement was effective during laptop work in reducing the cervical (−4.53 deg) and thoracic flexion angles (−3.14 deg) as well as the cervical erector spinae (−10.31%) and multifidus (−15.57%) muscle activities, and resulted in lower discomfort. The typing task was associated with higher muscle activity and awkward posture compared with the mouse work. As for workstation setup, simple modifications may reduce risk factors of musculoskeletal complaints.

Acknowledgments

The authors would like to acknowledge the students who participated in this research as well as all those who helped us during performing this research.

Additional information

Funding

No funding was received for performing the present study.

Notes on contributors

Mohammad Yadegaripour

Mohammad Yadgaripour received the PhD degree in corrective exercise and sports injuries from Kharazmi University of Tehran, Iran, in 2019. He is a Teacher and Adjunct Professor in Farhangian University – pardis of Allameh Tabatabai of Khorramabad, Iran. His research interests include exercise therapy, core stability, and work-related musculoskeletal problems.

Malihe Hadadnezhad

Malihe Hadadnezhad holds a BSc in physical therapy from Shahid Beheshti University, MA and PhD in corrective exercise and sports injuries from Tehran University and is Assistant professor in Department of Biomechanics and sport injuries in Kharazmi University. Her researches focus on exercise therapy, rehabilitation and corrective exercises.

Ali Abbasi

Ali Abbasi is an Assistant Professor in Sports Biomechanics at Kharazmi University. He focuses his research on the Nonlinear Dynamic Analysis in Sports Biomechanics, coordination, coordination variability in repetitive human movements, Neuromechanics and Gait analysis.

Fereshteh Eftekhari

Fereshteh Eftekhari holds a PhD in sports biomechanics from Kharazmi University of Tehran. She is an assistant professor at Shiraz University. Her current research focuses on neuromuscular control and biomechanical analysis of sport and basic movement.

Afshin Samani

Afshin Samani received the PhD degree in biomedical engineering and science from Aalborg University, Denmark, in 2010. He is currently an Associate Professor in sports science and ergonomics. His research interests include the methods of quantification of work exposure in relation to musculoskeletal disorders.