{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,23]],"date-time":"2026-08-23T17:36:32Z","timestamp":1787506592590,"version":"build-2736575974"},"reference-count":30,"publisher":"SAGE Publications","issue":"4","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["WOR"],"published-print":{"date-parts":[[2023,8,11]]},"abstract":"<jats:p>BACKGROUND: Smartphones cause physiological problems due to inappropriate postures and extensive usage. India, being the second leading country with the highest number of smartphone users (492 million in 2021), has witnessed a significant rise in smartphone-related musculoskeletal disorders (MSD). OBJECTIVE: This study compared the effects of 60-min smartphone gameplay on head flexion angle, muscle activity, and loads at C7 on Indian adolescents. METHODS: A subjective assessment was conducted on 1659 participants, of which, 40 young male adults aged between 20\u201328 years performed the experimental trial. Muscle (Sternocleidomastoid) activity, head flexion angle, and load acting at the neck (C7) were analyzed through postural assessment, pre-and post-subjective analysis. RESULTS: Participants maintained an average of 28.46\u00b0\u00b14.04\u00b0 head flexion angle for more than 43\u200amin (71%) in an hour while performing the task. The muscle activity increased to 23% (p\u200a&lt;\u200a0.001) of MVC at the end of the task compared to the beginning. CONCLUSION: The results indicated a significant increase in muscle activity (1.61 times), spinal loads (4.6 times) and subjective discomfort (2.9 times) after prolonged smartphone usage. It is evident that various aspects (duration, posture, content) play a vital role in smartphone-related MSD and there is a potential risk of cervical spine problems. The increased loads reduce muscle stiffness and increase intervertebral disc pressure.<\/jats:p>","DOI":"10.3233\/wor-220422","type":"journal-article","created":{"date-parts":[[2023,2,10]],"date-time":"2023-02-10T13:22:01Z","timestamp":1676035321000},"page":"1413-1425","source":"Crossref","is-referenced-by-count":5,"title":["Influence of smartphone game play on head flexion angle, muscle activity, and load at C7 among adolescents"],"prefix":"10.1177","volume":"75","author":[{"given":"Bhanu Priya","family":"Dandumahanti","sequence":"first","affiliation":[{"name":"Department of Mechanical Engineering, SRM Institute of Science and Technology, Chengalpattu, Tamil Nadu, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Murali","family":"Subramaniyam","sequence":"additional","affiliation":[{"name":"Department of Mechanical Engineering, SRM Institute of Science and Technology, Chengalpattu, Tamil Nadu, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"179","reference":[{"issue":"3","key":"10.3233\/WOR-220422_ref1","doi-asserted-by":"crossref","first-page":"367","DOI":"10.3233\/WOR-182819","article-title":"Factors associated with neck disorders among university student smartphone users","volume":"61","author":"Namwongsa","year":"2018","journal-title":"Work"},{"key":"10.3233\/WOR-220422_ref5","first-page":"1","article-title":"Text neck: an adverse postural phenomenon","author":"Fiebert","year":"2021","journal-title":"Work"},{"key":"10.3233\/WOR-220422_ref6","doi-asserted-by":"crossref","first-page":"102884","DOI":"10.1016\/j.apergo.2019.102884","article-title":"Head flexion angle when web-browsing and texting using a smartphone while walking","volume":"81","author":"Han","year":"2019","journal-title":"Applied Ergonomics"},{"key":"10.3233\/WOR-220422_ref7","doi-asserted-by":"crossref","first-page":"160","DOI":"10.1016\/j.apergo.2017.10.018","article-title":"Spinal kinematics during smartphone texting\u2013A comparison between young adults with and without chronic neck-shoulder pain","volume":"68","author":"Xie","year":"2018","journal-title":"Applied Ergonomics"},{"issue":"3","key":"10.3233\/WOR-220422_ref8","doi-asserted-by":"crossref","first-page":"183","DOI":"10.14257\/ijbsbt.2015.7.3.19","article-title":"A comparison of cervical flexion, pain, and clinical depression in frequency of smartphone use","volume":"7","author":"Park","year":"2015","journal-title":"International Journal of Bio-Science and Bio-Technology"},{"issue":"2","key":"10.3233\/WOR-220422_ref9","doi-asserted-by":"crossref","first-page":"1091","DOI":"10.1080\/10803548.2020.1863657","article-title":"Prevalence of mobile device-related lower extremity discomfort: a systematic review","volume":"28","author":"Legan","year":"2022","journal-title":"International Journal of Occupational Safety and Ergonomics"},{"issue":"2","key":"10.3233\/WOR-220422_ref10","doi-asserted-by":"crossref","first-page":"734","DOI":"10.1080\/10803548.2020.1827561","article-title":"Prevalence of mobile device-related musculoskeletal pain among working university students: A cross-sectional study","volume":"28","author":"Legan","year":"2022","journal-title":"International Journal of Occupational Safety and Ergonomics"},{"issue":"1","key":"10.3233\/WOR-220422_ref11","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1113\/jphysiol.2007.139477","article-title":"Muscle fatigue: what, why and how it influences muscle function","volume":"586","author":"Enoka","year":"2008","journal-title":"The Journal of Physiology"},{"key":"10.3233\/WOR-220422_ref12","doi-asserted-by":"crossref","unstructured":"Wan J-j , Qin Z , Wang P-y , Sun Y , Liu X . 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