Date of Award
Master of Physical Therapy (MPT)
Computer Terminals; Cumulative Trauma Disorders; Human Engineering
Laptop computers have become a common feature in both the workplace and the home. Computer technology has brought about vast benefits in terms of productivity and efficiency; however, the benefits have not come without repercussions. The wide use of laptop computers has without a doubt created an environment in which the user is susceptible to upper extremity cumulative trauma disorder (UECTD), also referred to as repetitive trauma disorder or overuse syndrome. The cost of UECTD to the individual and potentially his/her employer is enormous costing the United States alone an estimated $42 billion per year. Through ergonomic considerations, an optimal work environment for laptop use can reduce injury, worker's compensation costs, medical visits and employee absenteeism while improving comfort and productivity.
Purpose: The purpose of this study was to determine the most ergonomically correct posture for laptop computer use.
Methods: Ten subjects, both male and female, between the ages of22 and 29 years old, were tested. Electromyographical (EMG) and motion analysis data were collected from each subject. Each subject typed one sentence in the four following positions: 1) in the "industry standard" position for the head, neck, eyes, shoulders, forearms and wrists on a desktop computer; 2) in the "industry standard" position for the shoulders, forearms and wrist on a laptop computer; 3) in the "industry standard" position for the head, neck and eyes; 4) laptop computer positioned 30 inches in height from the floor.
Results: The study revealed that the "industry standard" position for the shoulders, forearms and wrists may be the most ergonomically correct position for laptop use due to the least amount of overall EMG activity in the studied musculature-upper trapezius, flexor digitorum superficialis, extensor digitorum.
Conclusion: Laptop computer use, in the researcher's opinion, has no ergonomically correct position--due to the strain still endured by the head, neck and eyes--but rather a most ergonomically "forgiving" position which is the "industry standard" position for the shoulders, forearms and wrists.
Kolar, Scott, "A motion-analysis and electromyographic study of the upper trapeziues and forearm musculature while tpying [i.e. typing] at different heights on a laptop computer" (2001). Physical Therapy Scholarly Projects. 264.