Acute Pain, Neck Extensor Endurance, and Kinematic Changes Resulting from Sustained Neck Flexion during Smartphone Use

OCCUPATIONAL APPLICATIONS The National Occupational Research Agenda for Musculoskeletal Health in the United States identified that with the changing nature of the traditional office environment, mobile devices are now frequently used for longer durations, warranting research on the impacts of mobile computing on musculoskeletal health. A recent study of office workers showed that those with “smartphone overuse” were six times more likely to report neck pain. Working in pain may also result in withdrawal and less proactive extra-role behaviors at work (such as making recommendations at work and willing to help colleagues). We found that 30-minutes of mobile device use resulted in pain reporting in the neck and upper back when the device was used with neck flexion. This musculoskeletal pain could lead to acute concerns during the workday and long-term problems over time. TECHNICAL ABSTRACT Background: People commonly use their phones with a flexed neck. Such use is concerning because epidemiological studies have demonstrated a direct relationship between prolonged neck flexion and neck pain, and mobile device use is associated with neck pain development. Purpose: Determine the repeatability of neck and upper back pain symptom development among young adults (ages 18-29) during 30-minutes of smartphone use with a flexed neck and compare neck flexion range of motion, neck extensor endurance, and posture among participants who develop neck and/or upper back pain during the task compared to those who do not develop pain. Methods: Participants (n = 40) came to the lab on two days separated by one week. They completed a 30-minute smartphone use trial with the device in their lap to elicit neck flexion. Participants were separated into pain groups based on a 10-mm change in their self-reported pain reports on a 100-mm visual analog scale (VAS). Pre-post tests and kinematics during the 30-minute trial were compared between individuals who did and did not consistently develop pain. Results: Seventy-five percent of the total study sample were categorized in the same pain category in the two trials using VAS score change. Of those participants, 66% developed neck pain during 30-minutes of smartphone use with sustained neck flexion. The most common symptom description was “aching.” Pain developers had a lower cervical extensor test duration after 30-minutes of smartphone use than before smartphone use. Conclusions: Two-thirds of young adults developed consistent neck and/or upper back musculoskeletal pain that they described as aching after 30-minutes of smartphone use with sustained neck flexion. Since the nontraditional work environment may result in the use of these devices, employers will need to be aware of the potential consequences of sustained postures during mobile device use and develop methods to mitigate pain.