Sports participation and low back pain in schoolchildren

Abstract

BACKGROUND:

Low back pain (LBP) is one of the biggest health problems worldwide.

OBJECTIVES:

The purpose of this study was to investigate the association between sports participation (duration and type) and LBP related outcomes in childhood.

METHODS:

This cross-sectional study involved 5 ${}^{\rm th}$ and 6 ${}^{\rm th}$ grade primary school students. The final sample included 2,032 children aged 10–12 years old. Children completed a questionnaire about the prevalence of LBP and some LBP-related outcomes. In addition, the participants were surveyed about the type of sport they did and the duration.

RESULTS:

There appears to be no relation between sports participation and severity of LBP-related outcomes studied, independently of their duration. Participating in football $\geqslant$ 4 hours per week was associated with a decrease of six LBP-related outcomes (OR ranging from 0.54 to 0.66). Basketball participation does not seem to affect the development of back problems amongst children.

CONCLUSIONS:

It can be suggested with caution that doing sport is not dangerous for LBP problems in children aged 10–12 years old. Nevertheless, this suggestion should be tested with further longitudinal and intervention studies to confirm the results.

Keywords

Motor activity football basketball prevalence low back pain

1. Introduction

Low back pain (LBP) is one of the biggest health problems worldwide [4, 38]. Low back pain often begins during childhood, however, during adolescence, the prevalence reaches similar values as in adults [24]. Some studies have examined the associated factors of LBP in children, such as weight, height, body mass index (BMI), gender, genetics, and physical activity [11, 16, 32, 36]. However, scientific evidence regarding the role of physical activity in the prevalence of LBP is controversial [34]. Cardon and Balagué [8] systematically reviewed the literature and concluded that a high level of physical activity was associated with an increase of LBP. Auvinen et al. [3] found associations between a high level of leisure physical activity and reports of LBP in a Finnish cohort of 5,999 adolescents aged 15–16. However, in a longitudinal study conducted by Aartun et al. [2], 1,348 Danish children aged 11–15 were included and followed for 2 years, and the authors showed no associations between different levels of physical activity and spinal pain. Paradoxically, it has been suggested that high physical activity levels in childhood might protect against LBP in early adolescence [41].

According to literature, the relationship between LBP and doing sport also remains controversial. Kamada et al. [18] recently pointed out that increases in doing sport by 1 h/wk provoke a 3% higher probability of developing pain 1 year late. In this line, Sato et al. [31] conducted a cross-sectional study in 43,460 children and adolescents aged 9–15 and showed that the lifetime of LBP was significantly higher in those who did sport (34.9%) compared to their inactive counterparts (21.3%). On the contrary, the findings of Mogensen et al. [25] reported that there was no relation between back problems and doing sport. Moreover, the cross-sectional survey by Sjolie [35] found a protective effect of some sports in LBP.

It is worth noting that some factors can influence these associations, for instance, the time spent doing sport and the type of sport [5]. The adequate amount of sport to avoid LBP is ambiguous, with studies reporting an increase of LBP for some sports and a decreased LBP for others. Engaging in sport 0.5–1 hours per week has been associated with less LBP [33]. Conversely, Hangai et al. [14] suggested that excessive exposure to competitive sports was significantly associated with LBP. Similarly, Kovacs et al. [22] reported a significant association between LBP and doing any type of sport more than twice per week in schoolchildren aged 13 to 15. To the best of our knowledge, this study is the only one conducted with Spanish children regarding the effect of sports participation to LBP. However, another cross-sectional survey showed no statistically significant trend between the number of hours doing sport and LBP problems [25].

It seems that some types of sports could be potentially harmful or beneficial in developing or protecting LBP in children. Those sports that place greater stress on the lumbar region structures increase the probability of LBP, whereas sports which place less stress on the lumbar spine may reduce the associated factors of LBP [12]. In football and basketball occur high-energy impacts, flexion, extension, and torsion of the spine which could cause an increase in complaints about LBP, and in turn, a growth of its negative consequences. Pasanen et al. [29] recently found that LBP was common in basketball players in a cross-sectional study conducted on 401 adolescent and young adults aged 12 to 21. Likewise, Bejia et al. [6] showed strong associations between LBP and football in a cohort of 622 Tunisian schoolchildren and adolescents. In the aforementioned study of Hangai et al. [14], the association between participating in football and basketball and LBP was confirmed. There seems to be a trend that relates LBP to football and basketball. However, these associations have been studied scarcely, hence clarification of this research question is warranted. The purposes of the study were 1) to examine the relationship among associated factors and LBP outcomes (specifically: nine LBP-related outcomes) in children and 2) to investigate the association between sports participation (duration and type) and LBP outcomes in childhood.

2. Material and methods

2.1 Study sample and design

The study sample involved 5 ${}^{\rm th}$ and 6 ${}^{\rm th}$ grade primary school students from Majorca (Spain). The study covered the final sample of 2,032 participants (with a reliability level of 95% and determined sampling error of 2%) aged 10–12, of whom 1,089 were boys (53.6%) and 943 were girls (46.4%), with a mean age of 11.1 (23.9% were 10 years old, 43.9% were 11 years old, and 32.1% were 12 years old).

All schools in Majorca (244 schools) received a letter inviting them to participate in the study and informing about the characteristics and objectives of the study. Finally, 26 schools agreed to participate in the study. All participants were informed about the purpose of the study and its procedure. The data were collected by a study coordinator in each school, who was a school teacher that had previously been trained for that purpose. In each school, a routinely scheduled physical education class was used for data collection. Each school’s study coordinator explained the objectives of the survey to the students. After the explanation, the students were given the questionnaires to be completed.

Students’ parents or tutors were requested to give their consent for children to participate in the study. The study was conducted according to the guidelines of the Declaration of Helsinki, and all procedures involving human participants were approved by the University Balearic Islands Ethics Committee (protocol number 2299).

2.2 Instruments

The instrument was based on a validated questionnaire utilised in previous studies in Majorca with schoolchildren population [13, 28]. In addition, the questionnaire used in this study was previously used in a postural education programme on 173 children of similar age (mean $=$ 10.7 years old) [39]. For this study, LBP was defined as pain or discomfort in the low-back region, from the lower rib curvature to the lower part of the seat region.

Table 1
Participants’ characteristics by gender and sports participation

	All ( $n$ 2032)	Boys ( $n$ 1089)		P-value	Girls ( $n$ 943)		P-value
		Sport ( $n$ 772)	No sport ( $n$ 317)		Sport ( $n$ 639)	No sport ( $n$ 304)
Weight (kg)	42.06 $\pm$ 9.59	42.14 $\pm$ 9.58	43.73 $\pm$ 10.72	0.005	40.92 $\pm$ 9.09	42.49 $\pm$ 9.12	0.963
Height (cm)	148.42 $\pm$ 9.24	148.53 $\pm$ 9.36	148.40 $\pm$ 9.37	0.627	147.99 $\pm$ 9.22	149.03 $\pm$ 8.80	0.439
BMI (kg/m2)	19.01 $\pm$ 3.58	19.00 $\pm$ 3.37	19.75 $\pm$ 3.95	0.008	18.63 $\pm$ 3.63	19.05 $\pm$ 3.47	0.686
Lifetime LBP, $n$ (%)	1345 (66.2)	457 (59.2)	184 (58.0)	0.725	486 (76.1)	218 (71.7)	0.152
Severe LBP, $n$ (%)	137 (6.8)	52 (6.7)	14 (4.4)	0.145	50 (7.8)	21 (6.9)	0.618
LBP impeding usual activities, $n$ (%)	562 (27.7)	184 (23.8)	77 (24.3)	0.873	212 (33.2)	89 (29.3)	0.230
Treatment received for LBP, $n$ (%)	310 (15.3)	108 (14.0)	49 (15.5)	0.531	98 (15.3)	55 (18.1)	0.283
LBP in bed, during the night, or	253 (12.5)	82 (10.6)	26 (8.2)	0.225	95 (14.9)	50 (16.4)	0.529
upon waking, $n$ (%)
LBP during last week, $n$ (%)	277 (13.6)	91 (11.8)	40 (12.6)	0.702	105 (16.4)	41 (13.5)	0.243
LBP during or at the end of	482 (23.7)	147 (19.0)	69 (21.8)	0.306	186 (29.1)	80 (26.3)	0.373
PE class, $n$ (%)
Diagnosis of scoliosis, $n$ (%)	235 (11.6)	41 (5.3)	30 (9.5)	0.230	45 (7.0)	27 (8.9)	0.628
Diagnosis of different leg	143 (7.0)	76 (9.8)	39 (12.3)	0.012	79 (12.4)	41 (13.5)	0.320
length, $n$ (%)

Data are mean and standard deviation, unless $n$ (%) is indicated; Sports: sports participation; No sports: no participation in any sport; BMI: body mass index; PE: physical education; LBP: low back pain. Significant differences by analysis of t-test (dependent variable: weight, height or BMI; group: sports participation). Significant differences between back outcomes and sports participation by $\chi^{2}$ . Significant OR and CI are highlighted in bold font for easier visual identification.

Table 2

Associations between associated factors and LBP outcomes

	All	Lifetime LBP	OR‡	95% CI	Severe LBP	OR‡	95% CI
Weight (kg)	–	–	1.01	1.00–1.02	–	1.02	1.01–1.04
Height (cm)	–	–	1.00	0.99–1.01	–	1.01	0.99–1.03
BMI (kg/m ${}^{2}$ )	–	–	1.03	1.00–1.06	–	1.06	1.02–1.10
Gender, $n$ (%)
Boys	1089 (53.6)	641 (47.7)	1	Reference	66 (48.2)	1	Reference
Girls	943 (46.4)	704 (52.3)	2.05	1.70–2.48	71 (51.8)	1.26	0.89–1.78
Age, $n$ (%)
10 years	486 (23.9)	317 (23.6)	1	Reference	27 (19.7)	1	Reference
11 years	893 (43.9)	600 (44.6)	1.09	0.86–1.37	68 (49.6)	1.40	0.88–2.20
12 years	653 (32.2)	428 (31.8)	1.01	0.79–1.29	42 (30.7)	1.16	0.71–1.92
BMI groups, $n$ (%)
Thinness	182 (9.0)	121 (9.0)	1.05	0.75–1.46	13 (9.5)	1.24	0.67–2.28
Normal weight	1373 (67.5)	885 (65.8)	1	Reference	79 (57.7)	1	Reference
Overweight	477 (23.5)	339 (25.2)	1.37	1.09–1.72	45 (32.8)	1.71	1.16–2.50

Descriptive data are shown as $n$ (%); LBP: low back pain; Severe LBP: severe low back pain; OR: odds ratio; CI: confidence intervals; BMI: body mass index. ‡The associations between associated factors and back pain outcomes were analysed by binary logistic regression with the calculation of the corresponding OR and 95% CI. Significant OR and CI are highlighted in bold font for easier visual identification.

Table 3

Logistic regression between time spent doing sport and LBP outcomes

LBP outcomes	Time spent doing sport
	$<$ 2 hours ( $n$ 597)		$\geqslant$ 2– $<$ 4 hours ( $n$ 612)		$\geqslant 4$ hours ( $n$ 362)
	OR‡	95% CI	OR‡	95% CI	OR‡	95% CI
Lifetime LBP	1.07	0.83–1.37	1.05	0.82–1.35	1.60	1.19–2.17
Severe LBP	1.23	0.76–2.01	1.55	0.98–2.47	1.36	0.79–2.36
LBP impeding usual activities	1.03	0.79–1.34	1.18	0.91–1.53	1.08	0.80–1.47
Treatment received for LBP	0.91	0.66–1.26	0.78	0.56–1.09	0.90	0.62–1.30
LBP in bed, during the night, or upon waking	1.15	0.81–1.63	0.83	0.57–1.20	1.22	0.82–1.81
LBP during last week	1.10	0.78–1.55	1.05	0.75–1.48	1.21	0.82–1.78
LBP during or at the end of PE class	0.95	0.72–1.26	0.92	0.69–1.21	0.89	0–89–1.65
Diagnosis of scoliosis	0.99	0.70–1.41	1.43	0.98–2.08	1.25	0.82–1.93
Diagnosis of different leg length	1.95*	1.20–3.16	1.33	0.86–2.04	1.38	0.82–3.20

OR: odds ratio; CI: confidence intervals; PE: physical education; LBP: low back pain. ‡The associations between the time spent doing sport and back pain outcomes were analysed by binary logistic regression after controlling for age, gender, and body mass index, and children participating in any sport (OR $=$ 1) was the reference group for the analyses. Significant OR and CI are highlighted in bold font for easier visual identification. Sports included: football, basketball, swimming, cycling, tennis, rhythmic gymnastics/gymnastics, futsal, athletics, volleyball, martial arts, handball, and others. *Caution should be paid when interpreting this ORs due to the small sample size in this group ( $n$ of cases with different leg length $=$ 20).

Data related to LBP included in the questionnaire were the following: LBP experience during the student’s lifetime (never, almost never, sometimes, often, always), LBP impeding usual activities (never, only when in pain, always), treatment received for LBP (no, rehabilitation, drugs, surgery, others), LBP in bed during the night or upon waking (yes, no), LBP during the last week (yes, no), LBP during or at the end of a physical education (PE) class (never, almost never, sometimes, often, always), diagnosis of scoliosis and diagnosis of different leg length (yes, no). The entire questionnaire is available in supplementary material.

The main data concerning potential associated factors for LBP included weight (kg), height (cm), BMI, gender (male/female), and age (years). Body Mass Index was calculated by dividing the weight (kg) by the height squared (m ${}^{2}$ ). The age and sex-specific BMI cut-off values proposed by the International Obesity Task Force were used to categorize the participants into the thinness, normal weight, and overweight (including obesity) categories [9].

In addition, regardless of the presence of LBP, details of sports participation (outside school hours) were reported in the questionnaire and the answers were classed as: football, basketball, swimming, cycling, tennis, rhythmic gymnastics, futsal, athletics, volleyball, martial arts, handball, and others. The children also included in the answer form the total number of hours per week that they spent doing sport (outside school hours) as a member of a sports club or in competitions. The answers were grouped into $<$ 2 hours, $\geqslant$ 2– $<$ 4 hours, and $\geqslant$ 4 hours.

2.3 Statistical analysis

Descriptive statistics, including means with SDs for continuous variables, frequency counts, and percentages for categorical variables, were calculated for the entire sample and for the subgroups based on sports participation, gender, and lifetime and severe LBP. We made comparisons using the t-test and the chi-squared test for continuous and categorical variables, respectively. The associations between associated factors, time spent doing sport, and LBP outcomes were analyzed by binary logistic regression with the calculation of the corresponding odds ratio (OR) and 95% confidence interval (CI). Specifically, to study the association between the time spent doing sport and LBP outcomes (Tables 3 and 4), the children who reported not participating in any sport were treated as the reference group (OR $=$ 1).

Table 4
Logistic regression between the time spent playing football and basketball and the occurrence of LBP

	Time spent doing sport
Football	$<$ 2 hours ( $n$ 220)		$\geqslant$ 2– $<$ 4 hours ( $n$ 181)		$\geqslant 4$ hours ( $n$ 176)
	OR‡	95% CI	OR‡	95% CI	OR‡	95% CI
Lifetime LBP	0.88	0.65–1.19	0.73	0.53–1.00	0.66	0.47–0.93
Severe LBP	0.83	0.46–1.48	0.59	0.28–1.23	0.69	0.33–1.45
LBP impeding usual activities	0.98	0.71–1.36	0.52	0.35–0.79	0.65	0.43–0.98
Treatment received for LBP	0.76	0.49–1.17	0.80	0.50–1.28	0.86	0.53–1.38
LBP in bed, during the night, or upon waking	0.77	0.48–1.25	0.55	0.31–0.98	0.57	0.31–0.98
LBP during last week	0.73	0.47–1.13	0.54	0.32–0.91	0.46	0.25–0.83
LBP during or at the end of PE class	0.82	0–57–1.18	0.65	0.42–0.99	0.57	0.36–0.91
Diagnosis of scoliosis	1.07	0.66–1.75	0.69	0.43–1.11	1.94*	1.00–3.76
Diagnosis of different leg length	1.79	0.84–3.83	0.66	0.36–1.20	0.54	0.30–0.98
Basketball	$<$ 2 hours ( $n$ 98)		$\geqslant$ 2– $<$ 4 hours ( $n$ 81)		$\geqslant 4$ hours ( $n$ 68)
	OR‡	95% CI	OR‡	95% CI	OR‡	95% CI
Lifetime LBP	0.87	0.58–1.31	0.90	0.58–1.41	1.30	0.77–2.20
Severe LBP	0.75	0.32–1.74	0.41	0.12–1.33	0.52	0.16–1.69
LBP impeding usual activities	1.14	0.74–1.75	1.23	0.78–1.94	1.22	0.73–2.03
Treatment received for LBP	1.25	0.74–2.10	1.58	0.93–2.69	1.41	0.78–2.56
LBP in bed, during the night, or upon waking	0.85	0.46–1.58	0.47	0.20–1.10	0.80	0.38–1.71
LBP during last week	0.87	0.48–1.58	1.24	0.70–2.19	1.12	0.58–2.17
LBP during or at the end of PE class	0.82	0.50–1.37	1.25	0.76–2.06	0.85	0.47–1.53
Diagnosis of scoliosis	0.87	0.47–1.61	0.69	0.37–1.28	1.85	0.73–4.70
Diagnosis of different leg length	1.49	0.59–3.74	0.85	0.38–1.89	2.78	0.67–1.15

OR: odds ratio; CI: confidence intervals; PE: physical education; LBP: low back pain. ‡The associations between the time spent playing football and basketball and the prevalence of low back pain were analysed by binary logistic regression after controlling for age, gender, and body mass index, and children participating in any sport (OR $=$ 1) was the reference group for the analyses. Significant OR and CI are highlighted in bold font for easier visual identification. *Caution should be paid when interpreting this ORs due to the small sample size in this group ( $n$ of cases with scoliosis $=$ 11).

To conduct the analyses, some LBP outcomes were created or dichotomized. Low back pain experience during the student’s lifetime was divided into two new outcomes: those children who answered “never, almost never, or sometimes” were considered into the variable named ‘lifetime LBP’, whilst those who answered, “often or always” were considered into the variable named ‘severe LBP’. On the other hand, the ‘LBP impeding usual activities’ outcome was dichotomized, with children who responded “never” forming a category and those who responded, “only when in pain or always” another category. The outcome called ‘treatment received for LBP’ was dichotomized: children who responded “no” formed a category and those who responded “rehabilitation, drugs, surgery or others” formed the other category. Low back pain during or at the end of a PE class was dichotomized: those children who answered “never” were considered into one category whereas those who answered, “almost never, sometimes, often, or always” were considered into another category. The analysis was done controlling for age, gender, and BMI. All the analyses were carried out using SPSS v23.0 statistics package for Windows.

3. Results

For the whole sample, 66.2% of the children experienced LBP. However, only 6.8% had severe LBP. Boys doing sport experienced 59.2% of lifetime LBP, and girls experienced 76.1% (Table 1). Weight and BMI were statistically higher in boys classed into the no-sport group (all $p<$ 0.008) compared with the sport group. All LBP-related outcomes were higher in girls (except for diagnosis of scoliosis in the no-sport group). Sixty-nine per cent of the children of our sample reported doing sport and 27.7% restricted their daily activity due to LBP. The prevalence of sport was the following: football 28.4%, basketball 12.2%, swimming 9.9%, tennis 9.8%, rhythmic gymnastics 8.6%, martial arts 7.7%, cycling 6.5%, volleyball 3.7%, handball 3.7%, futsal 3.1%, athletics 2.1%, and others 5.2%.

The OR and CI of having lifetime or severe LBP considering the associated factors are shown in Table 2. Lifetime LBP was twice as likely among girls compared to boys (OR 2.5, 95% CI 1.70–2.48). The probability of having lifetime and severe LBP increased significantly in overweight children compared to those with normal weight (OR 1.37, 95% CI 1.09–1.72 and 1.71, 95% CI 1.16–2.50, respectively). No significant association between age and lifetime or severe LBP prevalence was found.

Binary logistic regression analyses between the time spent doing sport and LBP outcomes, controlling for age, gender, and BMI are displayed in Table 3. The analyses showed that children who spent $\geqslant$ 4 hours doing sport were more likely to have lifetime LBP (OR 1.6, 95% CI 1.19–2.17) and not severe LBP than those who did not do any sport. There was no statistically significant trend in the number of hours that children reported doing sport and the remaining back-related outcomes. In sensitive analyses, we repeated the analysis using LBP dichotomized in a different mode (children who responded “never” formed one category and those who answered “almost never, sometimes, often, or always” the other category), and the results were not overall altered (data not shown).

Football and basketball were the most prevalent sports, allowing specific analyses on them separately (28.4% and 12.2%, respectively). Binary logistic regression analyses between the time spent playing football and basketball and LBP-related outcomes, controlling for age, gender, and BMI are shown in Table 4. Playing football $\geqslant$ 4 hours per week was associated with a decreased of six LBP-related outcomes (OR ranging from 0.54 to 0.66). Children spending 2 h or more playing football had lower associated factors in four LBP-related outcomes (OR ranging from 0.52 to 0.65). There was no statistical association between any of the LBP variables and the time spent playing basketball.

4. Discussion

Our study contributes to the scientific literature in four ways. First, the female gender and being overweight/obese increase the likelihood of both lifetime and severe LBP. Second, there appears to be no relation between sports participation and severity of back problems. Third, football participation seems to be a beneficial sport in preventing LBP among children. Fourth, basketball participation does not seem to have any effect in the development of back problems amongst children.

4.1 Associated factors and LBP

Our data revealed that those children who did not do sport were heavier; additionally, being an overweight child was associated with an increased probability of having LBP. Hence, it is reasonable to think that children who do sport are less likely to suffer back problems. An explanation of this might be that an excessive weight is associated with disc degeneration, postural modifications leading to vertebral endplate changes, and an inadequate disc nutrition which may predispose to experiencing LBP. Going a step further, physical activity has recently been found to be a powerful mediator in this relation (LBP and BMI), suggesting that the best predictors of this mediation role are moderate and high-intensity activities [37].

4.2 Sports participation and LBP

Engaging in sport was in general not related to back problems, although a high load of sports training ( $\geqslant$ 4 hours per week) was associated with lifetime LBP. Caution should be paid when this result is interpreted because children who spent between 4 and 20 hours were included in the group participating four or more hours per week (data not shown). Despite this, our results are in agreement with Watson et al. [40], who found that spending $>$ 4 hours per week doing sport was associated with childhood LBP. Although the intensity of the physical activities must be further clarified with future research, it appears evident that both extremes of activity levels (i.e. being very low and very high physically active) are associated with LBP [15]. For instance, LBP was related to physical inactivity in the cross-sectional study of Skoffer and Foldspang [36]. Notwithstanding, in the recent longitudinal study of Aartun et al. [1], it has been demonstrated that activities which require considerable physical effort seem to be a predictor of spinal pain. It appears that participating in a moderate physical activity does not cause spinal pain, whilst a sedentary lifestyle is linked to back problems. Noll et al. [27] recently conducted a study with high school athletes and found that athletes who practised 3 days or more per week had less prevalence of high-intensity and high-frequency back pain compared to those who only practised 1 or 2 days. Collectively, the findings of recent studies support that LBP incidence is lower or equal in children and adolescent athletes compared to young non-athletes [23, 26].

Additionally, we did not observe any association between sports participation and restriction in daily activities. Moreover, we found an apparent trend towards a decreased prevalence of treatment received for LBP with sports participation, but it was not statistically significant. Interestingly, our results showed that those children who engaged in sports had no more LBP during the night than the inactive ones, although sleep disorders are adversely associated with LBP [19]. Our results are in line with those of Rossi et al. [30], who found more sleeping problems due to LBP in non-members compared to members of girls sports clubs. It could be expected that doing sport might improve several dimensions of sleep and therefore a decrease in complaints during the night due to LBP. Doing sport had no effect on LBP during physical education classes. This finding concurs with Jones et al. [17], who were unable to demonstrate the association between new onsets of LBP and the time spent on physical education at school.

Another factor that has been explored in our study was the association between orthopedic disorders (scoliosis and leg length discrepancy) with sports participation. Traditionally, it has been thought that people with a spinal disorder should not do sport (except for swimming). However, the association between sports participation and scoliosis was generally not confirmed by our data. This finding is confirmed by the results found by Kenanidis et al. [20] who demonstrated that doing sport was not associated with the development of idiopathic scoliosis in adolescents. Notwithstanding, readers should be cautious about these results because youth scoliosis seems to be a multifactorial disease, and there is currently not enough scientific literature to determine if sports and scoliosis are in any way related [21]. Likewise, according to our findings, diagnosis of different leg length was generally not associated with sports participation. Leg length discrepancy can be a consequence of injury due to participation in sports during youth. In the systematic review of Caine et al. [7], no evidence of leg length discrepancy in youth doing sport was found. Thus, it seems that sports participation is not associated with an increased diagnosis of leg length discrepancy. However, caution should be paid when interpreting the results of orthopedic disorders due to the small sample size in some groups across time spent doing sport.

4.3 Football, basketball, and LBP

Football and basketball are the most played sports among Spanish children according to the nationally representative surveys in Spain [10] and also in our study sample. Consequently, we decided to study the effect of doing these sports on LBP outcomes. In general, our findings showed that playing football appears to be beneficial for the spine, whilst playing basketball seems to have no effects on LBP outcomes. It is noteworthy that those children who spent $\geqslant$ 4 hours playing football had an odds ratio significantly lower in most spine outcomes, compared with inactive ones. Previously, Sjolie [35] found an inverse association between LBP and football. However, Bejia et al. [6] have found LBP to be positively associated with time football participation. Football is the national sport in Spain and many other countries around the World. In our sample, football was mostly played by boys, only 11.1% were girls (data not shown), and therefore the analyses were adjusted by gender. However, Bejia et al. [6] did not, and this could be a possible explanation for this apparent difference. It is also noteworthy that the probability of having lifetime LBP for girls exceeded 2 compared with boys. Regarding basketball, in our sample, LBP outcomes were not associated with playing basketball, regardless of the activity duration. Our findings do not concur with other authors that found basketball participation as an associated factor for the occurrence of LBP [14, 29]. Although in our sample age was not a scientific factor, a huge body of evidence shows that LBP increases with age. Differences between ages of samples might explain this discrepancy (our participants were the youngest). On the other hand, Kovacs et al. [22] examined the association between sport participation and LBP in 7048 Mallorca adolescents, and they found that doing any sport (including football and basketball) more than twice per week was related to LBP (OR $=$ 1:23, 95% CI: 1.09–1.39). Our study goes one step further and provides a specific analysis for the most played sports in the world.

From a longitudinal point of view, it can be suggested that the relationship between sports and LBP is affected by other factors and cannot be explained by a single cause (duration of sports). Therefore, the main limitation of this study is to explain which of these other factors influence the relation between sports and LBP, for instance, information about the intensity of the sports might improve our understanding between LBP and sports participation during childhood. Other important weaknesses are the cross-sectional nature of the study and that we used a self-reported LBP questionnaire. Specifically, self-reported information about the diagnosis of scoliosis and different leg length should be considered as an important limitation. Furthermore, our findings could partially be due to the mode in which the LBP outcomes were collected. Nevertheless, our analyses were not controlled by socioeconomic level and maturation level due to unavailable data, and it would be interesting to adjust to these outcomes in future studies. A major strength of this research is that we have explored an understudied topic regarding LBP in children who engage in specific sports at different frequencies, in a relatively large sample with an homogenous age range.

To the best our knowledge, this investigation is the first to evaluate several LBP-related outcomes in children who engaged in sports at different frequencies compared to their inactive counterparts. Our results indicate that doing sport does not cause high incidence in the severity of LBP, regardless of weekly frequency. These findings are important for all professionals in charge of sports training in children population, specifically for football and basketball since they are the two most played sports in several countries. Despite our results, coaches and trainers are strongly recommended to pay special attention to good sports technique, as well as, with the introduction of preventive core-strengthening exercises.

In conclusion, we add to the scientific knowledge the following findings: 1) Severe LBP in children doing sport is rare, less than 8%, and it does not significantly differ from children who do not do sport; 2) The LBP due to doing sport has no effects on children’s daily activities, sleep disturbance, physical education classes, and orthopaedic disorders; 3) Football might be a beneficial sport against LBP, reducing by 50% the probability of LBP (ORs ranging between 0.4–0.6 depending on the LBP outcome); and 4) Basketball does not seem to influence the development of LBP in any way.

Footnotes

Acknowledgments

This study was supported by the University of Granada, Plan Propio de Investigación 2016, Excellence actions: Units of Excellence; Unit of Excellence and Health (UCEEs). The authors are grateful to Ms. Carmen Sainz-Quinn for assistance with the English language.

Conflict of interest

None to report.

References

Aartun

Boyle

Hartvigsen

Ferreira

Maher

Ferreira

Hestbaek

. The most physically active Danish adolescents are at increased risk for developing spinal pain: A two-year prospective cohort study. BMJ Open Sport Exerc Med 2016; 2: e000097.

Aartun

Hartvigsen

Boyle

Hestbaek

. No associations between objectively measured physical activity and spinal pain in 11-15-year-old Danes. Eur J Pain 2016; 20: 447-457.

Auvinen

Tammelin

Taimela

Zitting

Karppinen

. Associations of physical activity and inactivity with low back pain in adolescents. Scand J Med Sci Sports 2008; 18: 188-194.

Balagué

Mannion

Pellisé

Cedraschi

. Non-specific low back pain. Lancet 2012; 379: 482-491.

Balagué

Troussier

Salminen

. Non-specific low back pain in children and adolescents: Risk factors. Eur Spine J 1999; 8: 429-438.

Bejia

Abid

Salem

Letaief

Younes

Touzi

Bergaoui

. Low back pain in a cohort of 622 Tunisian schoolchildren and adolescents: An epidemiological study. Eur Spine J 2005; 14: 331-336.

Caine

DiFiori

Maffulli

. Physeal injuries in children’s and youth sports: Reasons for concern? Br J Sports Med 2006; 40: 749-760.

Cardon

Balagué

. Low back pain prevention’s effects in schoolchildren, what is the evidence? Eur Spine J 2004; 13: 663-679.

Cole

Lobstein

. Extended international (IOTF) body mass index cut-offs for thinness, overweight and obesity. Pediatr Obes 2012; 7: 284-294.

10.

Consejo Superior de Deportes. Study of Sporting Habits in School Population of Spain. Madrid: Underbau, 2011. Available from: http://www.csd.gob.es/csd/estaticos/dep-escolar/encuesta-de-habitos-deportivos-poblacion-escolar-en-espana.pdf.

11.

El-Metwally

Mikkelsson

Ståhl

Macfarlane

Jones

Pulkkinen

Rose

Kaprio

. Genetic and environmental influences on non-specific low back pain in children: A twin study. Eur Spine J 2008; 17: 502-508.

12.

Fritz

Clifford

. Low back pain in adolescents: A comparison of clinical outcomes in sports participants and nonparticipants. J Athl Train 2010; 45: 61-66.

13.

Gil Del Real

Kovacs

Gestoso

Mufraggi

Dieguez

. Evaluation of two questionnaires to determine exposure to risk factors for non-specific low back pain in Mallorcan schoolchildren and their parents. Eur J Public Health 1999; 9: 194-199.

14.

Hangai

Kaneoka

Okubo

Miyakawa

Hinotsu

Mukai

Sakane

Ochiai

. Relationship between low back pain and competitive sports activities during youth. Am J Sports Med 2010; 38: 791-796.

15.

Heneweer

Vanhees

Picavet

HSJ

. Physical activity and low back pain: A U-shaped relation? Pain 2009; 143: 21-25.

16.

Jones

Macfarlane

. Epidemiology of low back pain in children and adolescents. Arch Dis Child 2005; 90: 312-316.

17.

Jones

Watson

Silman

Symmons

DPM

Macfarlane

. Predictors of low back pain in British schoolchildren: A population-based prospective cohort study. Pediatrics 2003; 111: 822-828.

18.

Kamada

Abe

Kitayuguchi

Imamura

Lee

I-M

Kadowaki

Sawada

Miyachi

Matsui

Uchio

. Dose – response relationship between sports activity and musculoskeletal pain in adolescents. Pain 2016; 157: 1339-1345.

19.

Kelly

Blake

Power

O’Keeffe

Fullen

. The association between chronic low back pain and sleep. Clin J Pain 2011; 27: 169-181.

20.

Kenanidis

Potoupnis

Papavasiliou

Sayegh

Kapetanos

. Adolescent idiopathic scoliosis and exercising: Is there truly a liaison? Spine (Phila Pa 1976) 2008; 33: 2160-2165.

21.

Kenanidis

Potoupnis

Papavasiliou

Sayegh

Kapetanos

. Adolescent idiopathic scoliosis in athletes: Is there a connection? Phys Sportsmed 2010; 38: 165-170.

22.

Kovacs

Gestoso

Gil del Real

Lopez

Mufraggi

Mendez

. Risk factors for non-specific low back pain in schoolchildren and their parents: A population based study. Pain 2003; 103: 259-268.

23.

Legault

ÉP

Descarreaux

Cantin

. Musculoskeletal symptoms in an adolescent athlete population: A comparative study. BMC Musculoskelet Disord 2015; 16: 210.

24.

Michaleff

Kamper

Maher

Evans

Broderick

Henschke

. Low back pain in children and adolescents: A systematic review and meta-analysis evaluating the effectiveness of conservative interventions. Eur Spine J 2014; 23: 2046-2058.

25.

Mogensen

Gausel

Wedderkopp

Kjaer

Leboeuf-Yde

. Is active participation in specific sport activities linked with back pain? Scand J Med Sci Sports 2007; 17: 680-686.

26.

Mueller

Stoll

Prieske

Cassel

Mayer

. Incidence of back pain in adolescent athletes: A prospective study. BMC Sports Sci Med Rehabil 2016; 8: 38.

27.

Noll

Silveira

Avelar de

. Evaluation of factors associated with severe and frequent back pain in high school athletes. PLoS One 2017; 12: e0171978.

28.

Palou

Kovacs

Vidal

Gili

Borràs

Gestoso

Ponseti

. Validation of a questionnaire to determine risk factors for back pain in 10–12 year-old school children. Gazz Medica Ital Arch per le Sci Mediche 2010; 5: 199-205.

29.

Pasanen

Rossi

Parkkari

Kannus

Heinonen

Tokola

Myklebust

. Low back pain in young basketball and floorball players. Clin J Sport Med 2016; 26: 376-380.

30.

Rossi

, Pasanen K, Kokko S, Alanko L, Heinonen OJ, Korpelainen R, Savonen K, Selãnne H, Vasankari T, Kannas L, Kujala U, Villberg J, Parkkari J. Low back and neck and shoulder pain in members and non-members of adolescents’ sports clubs: The Finnish Health Promoting Sports Club (FHPSC) study. BMC Musculoskelet Disord 2016; 17: 263.

31.

Sato

Ito

Hirano

Morita

Kikuchi

Endo

Tanabe

. Low back pain in childhood and adolescence: Assessment of sports activities. Eur Spine J 2011; 20: 94-99.

32.

Scarabottolo

Pinto

Oliveira

Zanuto

Cardoso

Christofaro

DGD

. Back and neck pain prevalence and their association with physical inactivity domains in adolescents. Eur Spine J 2017; 26: 2274-2280.

33.

Shan

Deng

Zhang

Zhao

. Correlational analysis of neck/shoulder pain and low back pain with the use of digital products, physical activity and psychological status among adolescents in Shanghai. PLoS One 2013; 8: e78109.

34.

Sitthipornvorakul

Janwantanakul

Purepong

Pensri

van der Beek

. The association between physical activity and neck and low back pain: A systematic review. Eur Spine J 2011; 20: 677-689.

35.

Sjolie

. Associations between activities and low back pain in adolescents. Scand J Med Sci Sport 2004; 14: 352-359.

36.

Skoffer

Foldspang

. Physical activity and low-back pain in schoolchildren. Eur Spine J 2008; 17: 373-379.

37.

Smuck

Kao

MCJ

Brar

Martinez-Ith

Choi

Tomkins-Lane

. Does physical activity influence the relationship between low back pain and obesity? Spine J 2014; 14: 209-216.

38.

Steffens

Maher

Pereira

LSM

Stevens

Oliveira

Chapple

Teixeira-Salmela

Hancock

. Prevention of low back pain: A systematic review and meta-analysis. JAMA Intern Med 2016; 176: 199.

39.

Vidal

Borras

Ortega

Cantallops

Ponseti

Palou

. Effects of postural education on daily habits in children. Int J Sports Med 2011; 32: 303-308.

40.

Watson

Papageorgiou

Jones

Taylor

Symmons

DPM

Silman

Macfarlane

. Low back pain in schoolchildren: The role of mechanical and psychosocial factors. Arch Dis Child 2003; 88: 12-17.

41.

Wedderkopp

Kjaer

Hestbaek

Korsholm

Leboeuf-Yde

. High-level physical activity in childhood seems to protect against low back pain in early adolescence. Spine J 2009; 9: 134-141.

Sports participation and low back pain in schoolchildren

Abstract

BACKGROUND:

OBJECTIVES:

METHODS:

RESULTS:

CONCLUSIONS:

Keywords

1. Introduction

2. Material and methods

2.1 Study sample and design

2.2 Instruments

Table 1 Participants’ characteristics by gender and sports participation

Table 4 Logistic regression between the time spent playing football and basketball and the occurrence of LBP

4. Discussion

4.1 Associated factors and LBP

4.2 Sports participation and LBP

4.3 Football, basketball, and LBP

Footnotes

Acknowledgments

Conflict of interest

References

Table 1
Participants’ characteristics by gender and sports participation

Table 4
Logistic regression between the time spent playing football and basketball and the occurrence of LBP