Background/Aim: To assess digital media use, musculoskeletal pain and syndromes in adolescents and young adults from a public school. 

Materials and Methods: A cross-sectional study included 386 healthy adolescents that completed a questionnaire including demographic data, musculoskeletal pain, physical activity, and media use. The following musculoskeletal pain syndromes and repetitive strain injuries were investigated in students who reported musculoskeletal pain in the last three months: juvenile fibromyalgia, joint hypermobility syndrome, myofascial syndrome, tendinitis, bursitis, and epicondylitis.

Results: Inter-rater agreement between pretest and retest was 0.93. Musculoskeletal pain and syndrome were identified in 245/386(63%) and 55/245(23%), respectively. The median age was significantly higher in adolescents with musculoskeletal pain compared to those without this condition (14.69[11.9-22.5] vs. 14.41[10-18.8] years, p=0.018). The frequencies of computer use after 10pm (48% vs. 30%, p<0.001), internet use on weekends (6 hours [0-20] vs. 4[0-22],p=0.043), mobile phone use on weekends(8 hours[0-20] vs. 5[0-22], p=0.002), and mobile phone use after 10pm(83% vs. 69%, p=0.001) were significantly higher in the former group. Further comparisons between adolescents with and without musculoskeletal pain syndromes showed that female gender was significantly higher in the former group (74% vs. 27%, p<0.001). The internet use on weekdays (10 hours [0-24] vs. 5[0-20], p<0.001) was also significantly higher in adolescents with musculoskeletal syndrome.

Conclusion: Musculoskeletal pain was reported in approximately two-thirds of adolescents from a public school, and musculoskeletal syndromes occurred in one-quarter. Students with musculoskeletal pain were older and reported relevant use of digital media, while adolescents with musculoskeletal syndromes were predominantly female and reported important internet use on weekdays.

Media and electronic devices are relevant for entertainment and schoolwork in younger. An increasing exposure of the adolescent and young adults’ generation to media is a worldwide phenomenon. The most recent publication of the “TIC Kids Online Brazil” survey showed that 93% of this population used internet.1 Digital media use (computers, internet, electronic devices, and mobile phones) may be associated with various health issues, particularly recurrent musculoskeletal pain, pain syndromes and repetitive strain injuries. 

Musculoskeletal pain is the most frequent cause of recurrent non-inflammatory pain in adolescents, ranging from 30% to 65%. [2,3] The use of digital media is a risk factor for both musculoskeletal pain and musculoskeletal pain syndromes in healthy adolescents, and in those with chronic conditions (obese and asthma). [4,5] However, these reports included preferable analysis of subjects from private school with upper and upper/middle socio-economic classes.[4,6-8]

To our knowledge, there is no report that evaluate simultaneously digital media use, and the presence of musculoskeletal pain and musculoskeletal pain syndromes (joint hypermobility syndrome, juvenile fibromyalgia, myofascial syndrome, tendinitis, bursitis, and epicondylitis) in healthy adolescents and young adults, specifically students at public schools with low socioeconomic strata. 

Therefore, the objective of the present study was to assess digital media use, pain and musculoskeletal syndromes in adolescents and young adults from a public school. We also evaluated the possible associations between the presence of musculoskeletal pain and musculoskeletal syndromes and: demographic data, physical education at school, and digital media patterns.

A cross-sectional study was conducted during October 2018 to February 2019 in healthy adolescents of a public school, situated on the outskirts of São Paulo city, Brazil. 400 adolescents and young adults (10-22 years old) were invited to take part in the study, and n=390 (97.5%) agreed to participate. Adolescents and young adults with acute or chronic musculoskeletal pain and injuries secondary to recent infectious, onco-hematological, genetic, endocrine, and traumatic conditions (n=0), as well as those who filled out the questionnaire improperly (n=4), were systematically excluded. Adolescent or parental refusal was not observed. Therefore, the final sample of the present study was n=386 adolescents and young adults.

Informed consent was obtained from all subjects and their legal guardians. The study was approved by the Ethics and Research Committee of our University Hospital (number 24661313.9.00000.0065). 

Social and economic classes were evaluated by the Brazil Economic Classification Criteria of the Brazilian Association of Research Companies (ABEP), 2018.[9] 

An individual, confidential, and self-administered survey about pain and electronic media use was answered by adolescents and young adults. This standardized questionnaire was previously reported by our group.[8] All students completed a questionnaire covering the following aspects: demographic data; practice of physical activity and sports; availability, consumption pattern, and types of media used. Painful symptoms of the musculoskeletal system presented in the last three months were also evaluated. The questionnaire was applied during the period of one school class (maximum duration of 50 minutes). Pretest and retest of the questionnaire were carried-out with a 30-day interval in 25 subjects in October 2018 to assess the reliability of the subjects’ answers.

A specific musculoskeletal physical examination was also carried out, in a private environment of school class, by two trained physicians. This physical examination was performed in students who reported any complaint of pain in the musculoskeletal system in the last three consecutive months. The following musculoskeletal pain syndromes and repetitive strain injuries were systematically investigated: juvenile fibromyalgia, joint hypermobility syndrome, myofascial syndrome, tendinitis, bursitis, and epicondylitis. Juvenile fibromyalgia was diagnosed by widespread pain for at least three months and presence of at least 11/18 tender points examined bilaterally, by the American College of Rheumatology criteria.[10]  Joint hypermobility was defined according to Beighton’s criteria, and joint hypermobility syndrome as the presence of joint hypermobility associated with pain in the musculoskeletal system and the presence of 5 of the 9 criteria.[11] Myofascial syndrome was diagnosed in the presence of at least one active trigger points assessed bilaterally in specific muscles or muscular groups, and soft tissues stress injuries (tendinitis, bursitis, and epicondylitis), as previously described.[4-8]

The sample size provided power of 80% to find differences greater than 11.6% in the frequency of different digital devices use in adolescents and young adults with and without musculoskeletal pain (Graphpad StatMate 1.01, GraphPad Software, Inc., CA, USA). Continuous variables were presented as median (maximum and minimum value) or mean ± standard deviation. Categorical variables were presented as frequency and percentage. Kappa index was administered to evaluate the reliability of the questionnaire between the pretest and the retest. Comparisons between medians (variation) and mean ± standard deviation were calculated using the Mann-Whitney U test or the t-test, respectively. For categorical variables, differences were calculated using Fisher’s exact test or chi-square test. P values ≤ 0.05 were considered statistically significant.

The agreement between pretest and retest (Kappa index) was 0.93, demonstrating excellent reliability in the subject’ responses.

The study sample consisted of n=386 teens, and n=186 (48.1%) were females According to the ABE’s Brazil economic classification criteria, all adolescents and young adults belonged to lower and lower/middle socio-economic classes.

Regarding use of electronic media devices, 73% of the adolescents and young adults used computers (including desktops, laptops, and tablets), 70.9% played electronic games, 95.8% used the internet and 93.5% had a mobile phone. According to electronic games, the most used platform was “PlayStation” (34.5%), mobile phone (32%) and computer (desktop, laptop or tablet, 17.5%). The most reported position for students that played electronic games was “sitting on couch/chair”, in 28% of them. The positions “sitting on bed” and “sitting on floor” were reported in 25.7% and 15.2%, respectively.

The presence of musculoskeletal pain in the last three months was reported by n=245/386 subjects (63%). The musculoskeletal pain locations were back (n=142, 58%), neck (n=89, 36%), wrists and hands (n=88, 36%), shoulders and arms (n=78, 32%) and hips and legs (n=68, 28%). 

Sociodemographic data of the adolescents and young adults who reported musculoskeletal pain in the last three months were shown in Table 1. The median of current age was significantly higher in subjects with musculoskeletal pain versus those who did not report any pain [14.69 (11.9–22.5) vs. 14.41 (10–18.5) years, p=0.018]. The frequency of physical education at school was significantly lower in adolescents and young adults who reported pain (73% vs. 83%, p=0.033) (Table 1).

Table 2 comprised the characteristics of use of computers (desktops, laptops, tablets), electronic games, internet, and mobile phones in adolescents and young adults with musculoskeletal pain versus adolescents without pain. The frequencies of computer use after 10 pm (48% vs. 30%, p<0 p=0.001) p=0.043], p=0.016], p=0.002]>

Musculoskeletal pain syndrome was identified in n=55/245 (23%) of the adolescents and young adults: joint hypermobility syndrome in n=19/245 (8%), tendinitis n=18/245 (7%), myofascial syndrome n=17/245 (7%), and fibromyalgia n=7/245 (2.8%). 

Table 3 included sociodemographic data on subjects with musculoskeletal syndrome versus subjects without musculoskeletal syndrome. Females were significantly higher in students with musculoskeletal syndrome versus those without musculoskeletal syndrome (74% vs. 27%, p<0>

Table 4 included the characteristics of use of computers (desktops, laptops, tablets), electronic games, internet, and mobile phones in adolescents and young adults with musculoskeletal syndrome versus subjects without syndrome. The median of internet use on weekdays was significantly higher in students with musculoskeletal syndrome compared to those without musculoskeletal syndrome [10 (0–24) vs. 5 (0–20) hours/day, p<0>

Table 1: Sociodemographic data in adolescents with musculoskeletal pain versus adolescents without musculoskeletal pain.

Results are presented in n (%) and median (minimum-maximum value).

Table 2: Characteristics of use of computers (desktops, laptops, tablets), electronic games (EG), internet and mobile phones in adolescents with musculoskeletal pain versus adolescents without musculoskeletal pain.

Results are presented in n (%) and median (variation), h=hours. EG=electronic games

Table 3: Sociodemographic data in adolescents with musculoskeletal syndrome versus adolescents without this syndrome.

Results are presented in n (%) and median (minimum–maximum value).

Table 4: Characteristics of usage of computers (desktops, laptops, tablets), electronic games, internet and mobile phones in adolescents with musculoskeletal syndrome versus adolescents without this syndrome.

Results are presented in n (%) and median (variation), h=hours. EG=electronic games

The present study demonstrated that musculoskeletal pain was reported in approximately two-thirds of adolescents from a public school, and musculoskeletal syndromes occurred in one-quarter. Students with musculoskeletal pain were older and reported relevant use of digital media, while adolescents with musculoskeletal syndromes were predominantly female and reported important internet use on weekdays.

Our study identified a high frequency of musculoskeletal pain in students that using digital media. Indeed, a recent systematic review that assessed the prevalence and risk factors for musculoskeletal complaints associated with the use of portable devices, including adolescent population, identified musculoskeletal symptoms from ranging 1.0% to 67.8 %.[12] In another study, Silva et al.[13]  studied the prevalence of musculoskeletal pain in adolescents public schools from a northeastern Brazilian state and its association with the use of video games and computers, and identified musculoskeletal pain in 65.1% of adolescents. A similar frequency of musculoskeletal pain (61%) was also observed by Queiroz et al. [8], who evaluated teens from a private school in the city of São Paulo. Another recent systematic review on musculoskeletal complaints related to mobile phone use, including analyses of adolescent population, showed musculoskeletal pain from 8.2% to 89.9% in users of this technology.[14]

In addition, musculoskeletal pain, usually underdiagnosed, is a well-known cause of pain and functional disability, and may interfere with adolescents’ performance and productivity in everyday activities. In fact, pain in the upper limbs, shoulders, and neck has already been associated with lower education levels, absenteeism, and compromised recreational activities. [15,16] In the present study, the most frequent sites of musculoskeletal pain reported by students were back (58%), neck (36%), wrists and hands (36%). 

It is important to emphasize that our study evaluated the use of different media devices and that most of the recently published studies on the association of musculoskeletal pain and the use of electronic devices are restricted to the evaluation of smartphones and mobile phones in general.[12,14,17,18] In these studies, the neck region is most commonly reported as the site of pain, with prevalence ranging from 17.3% to 67.8%.[12,14] 

Neck pain may be related to anterior posture of the head while using electronic devices. Furthermore, the increase neck flexion angle while using an electronic device seems to be a risk factor for this musculoskeletal pain, and flexing the head frontward to varying degrees dramatically increases weight loads on the cervical spine.[12,17,18] The increased prevalence of back pain in the teens was also evidenced by Bento et al.[19], identifying 46.7% of back pain among adolescents associated with the pattern of electronic devices use, particularly laptops, tablets, and mobile phones. 

Different factors, including sociodemographic, behavioral and personal factors such as gender, age, socioeconomic status, physical exercise, type and pattern of electronic device usage, activities performed with such devices, such as texting or internet browsing, and other factors such as posture and ergonomics are considered as associated factors for musculoskeletal pain related to electronic devices.[20-25] We reinforced previous study identified that students with musculoskeletal pain were older and reported relevant use of digital media, particularly in those using computers and mobile phones after 10 pm and among them that used the internet and mobile phones for longer periods, on weekdays and weekends, while adolescents with musculoskeletal syndromes were predominantly female and reported important internet use on weekdays.

This research has methodological strengths. The assessment of self-reporting in the standardized questionnaire was important, and this instrument included photos of different body areas to indicate the location of musculoskeletal pain. The use of a questionnaire with excellent test–retest reliability was also relevant for this, minimizing memory bias. Another strength of the study was a specific physical examination of the musculoskeletal system by the trained researcher, identifying joint hypermobility syndrome (8%), tendonitis (7%), myofascial syndrome (7%), and fibromyalgia (2.8%). In this study, the exclusion of recent causes of musculoskeletal pain — particularly infectious, rheumatological, oncological and traumatic ones — was also relevant, since these conditions can induce recurrent and chronic pain, even in patients with mild changes on physical examination. 

However, this study has limitations. Other issues related to musculoskeletal pain and musculoskeletal pain syndromes, such as emotional disturbances, sleep abnormalities, use of heavy school bags (more than 10% of the adolescent’s weight), ergonomic assessment, and other risk behaviors have not been studied. Additionally, self-reporting of electronic device usage is likely to include a moderate amount of time, restricted to the three months prior to the assessment. New and continuous studies are needed to evaluate ergonomics, such as body posture and the configuration of the place of predominant use of multiple electronic devices among this population group.

Acknowledgments: Our gratitude to Ulysses Doria-Filho for the statistical analysis support.

Authorship criteria: All named authors approved the final draft of the manuscript, approved the submission to the Journal, and be willing to take responsibility for it in its entirety.

Authors’ contribution: All the authors contributed substantially to the conception and design of the study and in the analysis and interpretation of data. All authors revised the work critically and approved the final version.

Ethics Committee name and study protocol number: CEP/CONEP number 24661313.9.00000.0065

Funding: This study was supported by grants from Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq 304984/2020-5 to CAS), Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP 2015/03756-4 to CAS) and by Núcleo de Apoio à Pesquisa “Saúde da Criança e do Adolescente” da USP (NAP-CriAd) to CAS.

Financial Disclosure: The authors have no financial arrangements with a company whose product figures prominently in the submitted manuscript or with a company making a competing product.