Prevalence of self-reported musculoskeletal pain symptoms among school-age adolescents: age and sex differences

1 Introduction

Non-specific symptoms of musculoskeletal pain is one of the common complaints which can begin in adolescence and have a sudden onset or long-lasting symptoms [1, 2]. The musculoskeletal pain symptoms in adolescents affect the performance of daily living activities such as studying, exercising, or social participating, which results in a great health burden and increases the cost of living.

The prevalence of musculoskeletal pain in some body areas depends on age and sex [3, 4]. A number of European studies have found that the areas with a high prevalence of musculoskeletal pain in children and young people were the neck and shoulders. Adamson et al. [5] reported that children aged 11–14 years had 28.2% of neck and back pain, while Vikat et al. [6] found that Finnish adolescents aged 12–18 years reported 15% of neck and shoulder pain and 8% of lower back pain. Diepenmaat et al. [7] found similar results among Dutch adolescents aged 12–16 years. Furthermore, previous research also found that the prevalence of musculoskeletal pain among children and youth increased with age [3, 5, 6, 8, 9], especially back pain [1, 10, 11, 12], and the prevalence was higher in females [1, 3, 7, 9, 13, 14].

Musculoskeletal pain symptoms especially at the shoulder area are found to be associated with headache [15]. Headache, one of the common public health problems in children and adolescents [16], can cause muscle tension, or is attributed to tight muscles in the shoulders, neck, scalp, and jaw. The prevalence of headaches and especially migraines among school-age children and adolescents has been studied and varies according to age and sex [3]. Brattberg [17] also found a 48% incidence of headache among Swedish schoolchildren aged 7–18 years, while Fichtel and Larsson [18] reported headache (42%) as the most common pain among girls.

The study of prevalence of musculoskeletal pain symptoms among school-age adolescents and exploring the factors affecting chronic and non-specific musculoskeletal pain symptoms is critical and essential. School-age adolescents, particularly in East Asia, sit and spend longer hours studying (5.5–7.5 h) during the day compared to those in Europe or the US [19]. Spending long hours studying in the classroom and after school within a competitive education society in these adolescents may cause a risk of having non-specific musculoskeletal pain symptoms [20]. The non-specific musculoskeletal symptoms are hypothesized to occur in early adolescence while they are studying in primary school. This study is therefore aimed to look at the prevalence and frequency of musculoskeletal pain symptoms in Thai school-age adolescents. Adolescence in this study is defined by WHO as any person between the ages of 10 and 19 years [21]. This study also examined the prevalence of musculoskeletal pain symptoms, including headache, by age and sex and the association of these symptoms with daily activities. The data was subgroup analyzed in two age groups: 10–14 years and 15–19 years, since early and late adolescents would have different biological and psychological development stages, and various interests according to their personal and environmental factors.

2 Materials and methods

3 Results

There were 2,750 participants who were recruited in this study, 1,389 school adolescents from Khon Kaen and 1,361 from Phitsanulok. Fifty percent of all participants (n=1,376) were male. Table 1 displays similar demographic data of participants from each site. There were about 20.0% of participants from each site that had underlying disease. More than 50% of participants with underlying disease had allergy. There were 16 missing data of weight and height from all participants. Data on musculoskeletal pain were not considered separately or compared between the two sites.

There were 2,093 adolescents (76.1%) that experienced musculoskeletal pain symptoms in at least one area in the previous 7 days, 73.0% (n=2,007) of students reported symptoms in the previous 12-month period, and 83.8% (n=2,304) reported pain both in the previous 7 days and 12 months. The remaining 446 (16.2%) students reported no musculoskeletal symptoms over their body areas in both the previous 7-day and 12-month periods. The mean value of pain severity was 3.82±2.06 out of 10 (95% CI 3.74–3.91) on the visual analog scale. About 66.3% of participants did not take any pain relief medication for this pain and 32.5% did not rest within 1 h when pain occurred. Table 2 shows the previous 7-day and 12-month prevalence of musculoskeletal pain in 10 body areas.

Headache was reported as having the highest prevalence among the pain symptoms in various anatomical areas during both the previous 7-day and 12-month periods in all groups. The other pain areas included the neck, shoulders, ankles or feet, wrists or hands, upper back, hips or thighs, knees, lower back, and elbows, in order of prevalence. Three areas including the elbow, knee, and ankles or feet had a higher prevalence in the male groups compared to the female groups. Table 2 also shows that older participants reported more prevalence of pain especially the head, neck, shoulders, upper back, lower back, and hip or thigh.

Table 3 shows the pain areas most reported and the frequency of pain from all participants who reported symptoms (n=2,284, missing=20). Headache was the most reported pain area among those who experienced musculoskeletal pain symptoms of all groups. The other significant pain areas were ankle or foot for the male groups aged 10–14 years, neck and lower back for the male groups aged 15–19 years, shoulder and ankle or foot for female groups aged 10–14 years, and neck and shoulder for female groups aged 15–19 years.

Data of routine activities related to musculoskeletal pain in the previous 12-month period adjusted for age and sex for all participants are shown in Table 4. The highest significant association of related activity with musculoskeletal pain in anatomical areas including the head, neck, shoulder, elbow, wrist/hand, upper back, lower back, hip/thigh, knee, and ankle/foot were computer use (head, OR=2.22), school bag carrying (neck, OR=2.05), school bag carrying (shoulder, OR=3.09), playing sports (elbow, OR=2.18), playing sports (wrist/hand, OR=1.85), school bag carrying (upper back, OR=1.93), sitting and doing homework (lower back, OR=1.75), playing sports (hip/thigh, OR=2.69), playing sports (knee, OR=2.13), and playing sports (ankle/foot, OR=2.68).

4 Discussion

The present study surveyed the prevalence of self-reported non-specific musculoskeletal pain symptoms among school-age adolescents 10–19 years old. The results show a high prevalence of 76.1% during the previous 7 days, 73.0% during previous 12 months and 83.8% during both 7-day and 12-month periods for musculoskeletal pain symptoms in different body areas, although the level of pain intensity was mild. The prevalence of musculoskeletal symptoms in different areas of the body during both periods of 7 days and 12 months were similar. Headache was the most common symptom experienced by both girls and boys in all age groups. Other common musculoskeletal pain areas were the ankles or feet for younger boys and girls, and the neck and shoulders for older boys and girls. Each previous study reported a varying prevalence rate depending on differences in the methodology, target population, examined symptoms, and recall period applied. A systematic review of headache in children and adolescents shows that prevalence rates ranged widely from 8% to 83% for both migraine and tension headaches, depending on the time period of reporting (yearly, monthly, weekly or daily) [23]. For the current study, each age group of school-age adolescents self-reported headaches in the past 7-day period from 33% to 60.3% and in the past 12-month period from 36.8% to 70.1%. However, the high prevalence of headaches in the current study’s adolescents included headaches affected by any causes, since we did not ask students to identify the type of headache when filling out the questionnaire.

We also found that Thai school-age adolescents reported a high prevalence of neck and shoulder pain, as did adolescents (from 15% to 28%) in European studies [5, 6] and adolescents aged 15–18 years (41.1%) in China [24]. Chronic pain in the neck and shoulder areas can result in referred pain to the head, causing headache. Since tension-type headache is quite common in adolescents, a previous study showed that the local and referred pains elicited from active trigger points in the head, neck, and shoulders shared similar pain patterns as spontaneous chronic tension type of headache in children [25]. Results suggest that neck and shoulder pain can begin in early adolescence and persist into chronic musculoskeletal problems in adulthood [1]. However, this assumption needs further investigation with a longitudinal cohort study.

Subgroup analysis confirmed that the prevalence rates of musculoskeletal pain symptoms were different depending on sex and age. The rates were higher in girls than boys in almost every anatomical area, except for the elbows, knees, ankles, or feet, comparable to several previous studies [1, 3, 7, 9, 13]. This may be due to hormonal changes during puberty, resulting in changes in physical, psychological and social awareness that are different between the sexes, with girls reporting higher levels of pain symptoms than boys [4]. In addition, the present study reported that older boys and girls tended to experience more musculoskeletal pain symptoms than younger groups, similarly to other previous studies [1, 3, 5, 6, 8, 9, 10, 11]. This study confirms reports from previous studies of spinal pain, especially neck and lower back pain, in that the prevalence increases with the age of the adolescents [1, 10, 11, 12]. The systematic review indicated that the number of children with back pain increased steadily until the late teens; however, back pain is uncommon in children younger than 10 years [12].

Furthermore, other results of this study are in accordance with previous research [26, 27] that the prevalence of lower extremity pain, especially at the knee, ankle and foot, was higher in younger adolescents. Our study found that the prevalence of knee, ankle, and foot pain was higher in boys aged 10–14 years compared to girls. In a previous study [26], the knee was the most common site of pain in the lower limbs, followed by the ankles and feet. This might be due to the prevalence of both traumatic and non-traumatic pain, as El-Metwally et al. [26] reported in Finnish adolescents, and the knee area was also the most common location of pain due to a direct trauma. Moreover, the school-age participants in the previous study were younger (mean ages range from 9 to 11 years) than those in our study. Non-traumatic lower limb pain among younger children (aged 9–10 years) can mainly have an effect during a growing period, with occasional relapses in the teenage years, which can persist or recur with age [27].

The relationships between daily activities and musculoskeletal pain were analyzed by controlling the influence of age and sex in different anatomical areas. We found the highest significant association between computer use and headache (OR=2.22, 95% CI 1.82–2.69) followed by the association between computer use and neck pain (OR=1.85, 95% CI 1.52–2.24). This is a similar result to a previous study in South African adolescents aged 14–18 that found that neck pain is associated with computer usage (OR=1.7, 95% CI 1.2–2.3) [25]. This previous study also found that many hours of computer usage were the only predictors of neck pain. Moreover, previous studies found that headache and neck pain may be attributed to a long period of sitting or maintaining a static posture [24] or to higher screen time, e.g. computer games, smart phones, or the Internet [28]. Thai adolescents, like those in the Chinese study [24], need to spend long hours sitting and studying in class and after school due to academic pressure, which shows an increasing prevalence of neck and shoulder pain in older adolescents. This neck and shoulder pain may be related to academic and psychological pressure. Furthermore, the current study shows a significantly high association of neck (OR=2.05, 95% CI=1.65–2.56) and shoulder pain (OR=3.09, 95% CI=2.48–3.85) with school bag carrying. In contrast, Shan et al. [24] found that the type of bag and method of school bag carrying were not significantly correlated with the prevalence of neck and shoulder pain. Carrying a backpack to school is more common among Thai adolescents compared to bag carrying, especially when they are at the secondary school level; however, the current study did not identify the weight of the bag, the type of school bag, and the method of bag carrying among the participants.

Finally, our study showed that playing sports was significantly associated with the prevalence of lower extremity pain such as the thigh (OR=2.69, 95% CI=2.2–3.3), knee (OR=2.13, 95% CI=1.7–2.6), or ankle and foot (OR=2.68, 95% CI=2.2–3.2). This was in accordance with a previous study [29] that lower limb pain prevalence has a significant linear association with sports activities. Adolescents who took part in sports activities seemed to suffer neck and shoulder pain less frequently than those who did not [30]. However, participating in organized sports or vigorous physical activities might affect the higher prevalence of pain in the lower extremities, and they can increase the risk of lower limb traumatic pain among young school-age adolescents. We hypothesized that young Thai children aged 10–14 years spend more time playing sports compared to older adolescents aged 15–19 years; the prevalence of lower extremity pain was therefore higher than that of spinal pain.

The present study is based on a middle-sized survey (n=2,750) representative sample of 10–19 year-old school adolescents from two sites in Thailand. In addition, a standard tool (the Standardized Nordic Questionnaire) [22, 31] was applied to data collection in the present study to self-report the musculoskeletal pain of adolescents. However, some limitations of the present study need to be noted. Firstly, the assessment of musculoskeletal pain used was a subjective measure by self-reporting over the previous 7 days or 12 months among school-age adolescents without a physical examination for confirmation. Therefore, the prevalence of musculoskeletal pain by self-reporting may be overstated by recall bias. Secondly, the results point out that students perform regular activities both at home and school that are associated with musculoskeletal pain, including computer use, school bag carrying, and playing sports. However, activities associated with musculoskeletal pain in this study give only a preliminary relationship; the associations with other factors were not analyzed, for example, demographic data including body mass index, socioeconomic status, emotional or psychosocial symptoms [6, 18], behavioral factors [5], and smoking [32]. Thirdly, the frequencies of having pain data were not clearly defined, but recorded as sometimes, often and always. A more detailed frequency (once a week, once a year, etc.) would make the frequency data more useful. Finally, this study did not ask participants to identify the type of or underlying reason for their headaches. Further studies should be designed to indicate the actual causality of the common pain areas in children and adolescents.

In conclusion, the prevalence of musculoskeletal pain symptoms of school-age adolescents differs among age groups and sex. Headache was found to be the most common musculoskeletal pain symptom and had the highest prevalence in Thai school-age adolescents. Additionally, headache and musculoskeletal pain symptoms are more prevalent in girls than in boys and these rates tend to be higher in older adolescents. Ankle or foot pain was a common musculoskeletal pain among younger boys and girls, which was associated with playing sports. Neck and shoulder pain was a common musculoskeletal pain among older boys and girls and was associated with computer use and school bag carrying.