Effect of neck flexion angles on neck muscle activity among smartphone users with and without neck pain

Ergonomics ◽  
2019 ◽  
Vol 62 (12) ◽  
pp. 1524-1533 ◽  
Author(s):  
Suwalee Namwongsa ◽  
Rungthip Puntumetakul ◽  
Manida Swangnetr Neubert ◽  
Rose Boucaut
Author(s):  
Christina A. Yee ◽  
Homayoon Kazerooni

Neck pain is common among occupations like dentistry and office work because workers in these professions tend to hold their necks in static flexion for extended periods of time. But there are few products available to help alleviate workers’ neck pain while still allowing them to carry out their daily tasks in varying environments. For example, office workers can use products like ergonomic chairs and desks to help promote proper posture, but these arrangements restrict workers to workspaces equipped with their necessary equipment and proper setup. Meanwhile, in the medical field, products like loupes, lights, and ergonomic workbenches are available to enhance visibility and reduce workers’ neck flexion angles. But these products have yet to fully eliminate the problem of neck pain especially in occupations like dentistry where static neck flexion is common. Therefore, the goal of this project is to develop a new neck support technology which alleviates neck pain caused by static neck flexion while still allowing workers full mobility and functionality in their workplace. Our design decreases muscle loading on the neck during neck flexion by reducing the moment on the neck using a device which acts as a “headrest” to support the head. In turn, the device redistributes forces to the upper body while still allowing full range of motion to the user. More specifically, our design applies an opposing force to the user’s forehead during neck flexion via a force generator attached to a headband which is attached to the head. The force generator is anchored to the upper body to permit use in varying environments without the need for special equipment or setups. We confirmed our design decreases muscle loading by building a prototype then performing surface electromyography (EMG) testing which showed not just a statistically significant reduction in neck muscle activity using one-way analysis of variance, but more distinctly a unanimous decrease in neck muscle activity during neck flexion for all seven test subjects with an overall average decrease of 60% among all subjects and 80% for certain subjects. Once we confirmed our design’s effectiveness in reducing neck muscle activity during static neck flexion which implied the ability to reduce neck strain, we improved our prototype’s functionality and aesthetics based on test subject feedback, our own observations, and dentists’ comments. Then, we performed workplace testing on two dentists with one dentist’s work focused mainly on hygiene while the other dentist’s work focused mostly on dental procedures. Overall, both dentists offered helpful feedback from different dental field perspectives for future prototype improvements with regards to comfort and functionality. They also provided promising comments regarding their visions for future device use which included training dental students on proper posture and applications in other occupations like office work and surgery.


Author(s):  
Eunjee Kim ◽  
Gwanseob Shin

Potential ergonomic issues associated with the use of a head mounted display (HMD) for office productivity applications have not yet been quantitatively evaluated. A laboratory experiment was conducted to quantitatively evaluate physical stresses and the productivity of the use of HMD. Twenty healthy participants conducted a document editing task for 60 minutes once with an external display and once with a HMD. Head rotation in sagittal and transverse planes, myoelectric activity of neck and shoulder muscles, subjective discomfort ratings and productivity were collected periodically during the task. Results found significantly (p<0.05) greater head rotation movements on both planes, neck muscle activities, and discomfort ratings and decreased productivity when conducting the task with the HMD as compared when using the external display. Difficulty in reading texts due to insufficient resolution of the HMD screen, additional load and neck flexion moment from the weight of the device were responsible for the greater physical stresses associated with the use of HMD.


Ergonomics ◽  
2021 ◽  
pp. 1-12
Author(s):  
Weerasak Tapanya ◽  
Rungthip Puntumetakul ◽  
Manida Swangnetr Neubert ◽  
Rose Boucaut

Work ◽  
2021 ◽  
pp. 1-8
Author(s):  
Fabiana Foltran Mescollotto ◽  
Érica Brito Gonçalves ◽  
Ester Moreira de Castro Carletti ◽  
Ana Beatriz Oliveira ◽  
Elisa Bizetti Pelai ◽  
...  

Background: Excessive use of smartphones may be associated with behavioral and physical health changes and might cause musculoskeletal alterations in the head and neck region. Objective: To evaluate the prevalence of smartphone addiction in college students and its correlation with symptoms of head and neck pain and masticatory and trapezius muscle activity while resting, before and after smartphone use. Methods: Twenty university students participated in the study. They answered the Smartphone Addiction Scale and the Fonseca Anamnestic Index. Next, the participants were seated and prepared for electromyography through the placement of surface electrodes on the masseter, temporal, and trapezius muscles. Rest condition data were collected for 10 seconds before and after 30 minutes of smartphone use. Results: The results showed that 35% of the evaluated individuals were classified as smartphone addicted and 35% reported no head or neck pain in the previous 30 days. There was no association between smartphone use and head and neck pain. In the electromyography, there was an increase in RMS values after smartphone use in the right and left masseter muscles and the left trapezius. Conclusion: College students presented a high prevalence of smartphone addiction and head and neck pain, but these were not statistically associated. There was a change in muscle activity only in the right trapezius muscles before and after 30 minutes of smartphone use. These findings are contrary to the current belief that the use of smartphones correlates with pain in the neck region and changes in the electrical muscle activity, leading to fatigue in the cervical muscles.


2016 ◽  
Vol 147 ◽  
pp. 613-617
Author(s):  
Gerrit Thiele ◽  
Patricia Kafka ◽  
Stefan Litzenberger ◽  
Anton Sabo
Keyword(s):  

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