Children are vital to the nation’s present and its future. Children today spend more time on screen and carry heavy school bags. As they are the future generation of the nation, creating awareness about maintaining a good posture in daily activities is essential. Research indicates that low back discomfort in teenagers may be a major risk factor for back pain in later life. One of the main strategies for lowering lower back discomfort is ergonomic seating and adopting appropriate posture when performing tasks. The variation of anthropometric measures of children, the performance of daily activities exposing children in various postures, and the physical design features of school furniture are the three factors which influence the postural health of school children. Low back pain in school children can predict low back pain in later years of life (Paranjape & Ingole, 2018). Musculoskeletal pain among school-aged children is a well-known concern as acknowledged by WHO. Between 16 and 86 percent of school children in wealthy nations report having musculoskeletal complaints at some point in their lives; in poor nations, the incidence is higher, ranging from 46.3 to 88.8 percent. Ergonomic Health Promotion Programme (EHPP) was planned to assess the musculoskeletal symptoms, and creating knowledge on ergonomics and given practice on stretching exercise which will reduce their musculoskeletal symptoms and maintain correct posture.

Objectives: The study was set with following objectives:
1. To assess the postural health, estimate the prevalence of musculoskeletal symptoms and assess the level of knowledge on postural health among school children,
2. To determine the effectiveness of Ergonomic Health Promotion Program among school children, and
3. To determine the association between selected background variables and postural health.

Research Hypotheses
H1: There will be a significant difference in postural health (postural practice & musculoskeletal symptoms) before and after EHPP between control and experimental group of school children. H2: There will be a significant difference in knowledge, postural health before and after EHPP between control & experimental group of school children.
H3: There will be a significant association between selected demographic variables and postural health among control and experimental group of school children.

Review of Literature
A cross-sectional study was conducted by Resende et al (2023) to assess the prevalence of postural changes among school children and adolescents. Hundred & Nine school children of both sexes with mean age of 13 years were evaluated in public school in the city of Brazil. The New York scale was used for posture analysis, measuring body weight, height, backpack weight, and body mass index (BMI). The ANOVA statistical test and Pearson’s correlation test were used, considering a significance level of 0.05. The result showed that general average of the scores of postural problems was 68.7 points, with a predominance in the head, spine, hips, trunk, and abdomen.

Menor-Rodríguez et al (2022) conducted a study to evaluate the influence of educational intervention to modify postural hygiene habits of school-age children. Using stratified multistage selection, they chose three public primary schools at random from the Galician provinces of Orense and Pontevedra. A sample of 479 pupils was acquired, which amounts to 2 percent of all 6- to 12-year-old children registered in those provinces for the 2015 2016 school year. After the intervention, there was improvement in the postural hygiene of the students. There were statistically significant differences in the amount of time they spent watching television (0.531 hours per day), how they carried their school supplies and books (using wheeled backpacks, increased from 58.5% to 64.1%), and how they improved their postural hygiene when watching television (more people chose to watch on a chair than to lie down). It was found that the harmful behaviours were improved and corrected by educational intervention, also the intervention had role in developing good postural hygiene practices at a young age.

Similarly, García-Soidan et al (2020) reported that although sedentary girls have greater balance than active boys, active children have better postural control than sedentary children. Thus, exercise training appears to support a more effective development of postural control.

Materials and Methods
This study was conducted using quasi experimental design after obtaining ethical clearance from the Institutional Ethics Committee of Apollo College of Nursing, Chennai. Formal consent was obtained from the children of selected schools and their parents. The study was carried out in two phases. The prevalence of the musculoskeletal problems among school children was assessed in phase I and the effectiveness of the EHPP on postural health was assessed in phase II. The sample size estimation was calculated by open epi for Phase I, based on the study conducted by Resende et al (2023). The calculated sample size was 174. Hence 300 samples were selected for this study considering 10 percent attrition and better generalisation. In Phase II, based on the study of Syazwan et al (2011), RULA score was used with mean as = 4.94, SD= 0.64 power (1-beta) %, 95 Alpha error (%) 80. mean = 4.94, SD= 0.64, power (1-beta) - 80%, Alpha error 95%. The required minimum sample size was 71. Therefore, considering an attrition rate of 10 percent, a total sample size of 80 were selected in each group. A pilot study was conducted among 10 percent of the calculated sample size to establish the feasibility. An extensive review of literature laid foundation for the selection and development of tools. The content validity was obtained from the field experts and the reliability was established by test retest and Cronbach’s alpha method. The study was conducted at four selected schools in Chennai viz. (1) Sri Vidhya Nikethan Matriculation School, Ambattur, (2) UCCK Matriculation Higher Secondary School, Athipattu, (3) TI School, Ambattur, and (4) Sethu Baskara Matriculation Higher Secondary School, Ambattur. Among these first two schools were chosen for pilot study and remaining two schools were chosen for main study. After obtaining initial introduction, the main study was conducted in 2 phases in two selected schools (one for experimental and one for control group). Data collection period was 45 days.

In phase I, total enumeration sampling technique was used for screening musculoskeletal symptoms among 300 students (150 students in each experimental and control group) studying in classes IV (n=50), class V (n=50) and class VI (n=50), standard using standardised Nordic Body Map Questionnaire: there were 50 students in each standard to maintain homogeneity. After initial introduction, the main study was conducted in 2 phases in two selected schools (1 for experimental and 1 for control group).

In phase I, screening for musculoskeletal symptoms was done among 300 students (150 students in each experimental and control group) studying in IV, V and VI standard using standardised Nordic Body Map Questionnaire. In Phase II, a sample of 160 children with mild to moderate musculoskeletal symptoms were included, they were selected from two different schools by consecutive sampling technique and were allotted to experimental group and control group (80 in each group).

The Intervention
The background variables of children were collected by interview method. Pre-test knowledge on ergonomic risk factors and assessment on postural practice was done by structured questionnaire in both the control and experimental groups before EHPP. The EHPP was given to the experimental group of children by teaching through power point presentation and demonstrating stretching exercise by sitting in the chair. In the recess, they were involved in such activities as Shoulder Rotation, Lifting the arms, Rolling the hands, Turning side to side, Stretching the arms & fingers, Stretching the hands, Triceps muscles stretching, Waving the hands (each exercise requiring 10 16 repetitions for 30 minutes). The correct way of carrying school bags was taught using posters and pamphlets. The school children were made to practice stretching exercises daily during physical education period for 21 days; after 21 days of intervention, post-test knowledge, postural practice and musculoskeletal symptoms were reassessed by using structured knowledge questionnaire and standardised Nordic Body Map Questionnaire (SNBMQ). Level of satisfaction regarding EHPP was assessed in the experimental group of children.

Results & Discussion (Tables 1-5)
There was a significant difference in pain score was higher than control group. Hence the hypothesis H1 " there will be significant difference in postural health (musculoskeletal symptoms) before and after EHPP between control and experimental group of school children" was retained.

Table 1: Frequency & percentage distribution of prevalence of musculoskeletal symptoms among control & experimental Group of school children (N = 300)

There was a significant difference in post-test knowledge score. Hence the research hypothesis H2 stating that "there will be significant difference in pre-test and post-test knowledge on postural health between control and experimental group of school children" was accepted.

Hence the research hypothesis H3, i.e. "there will be a significant association between selected demographic variable and postural health among control group" was accepted with respect to class of study, bag weight and postural health in posttest.

Table 2: Frequency and percentage distribution of level of postural health (practice & pain) in control & experimental group of school children (N = 160)
Table 3: Comparison of mean & standard deviation of postural health (Practice & Pain) between pre & post-test among control & experimental group of school children (N = 160)
Table 4: Comparison of mean & standard deviation of knowledge scores on ergonomics pre-test & post-test between control & experimental group of school children (N = 160)Table
5: Association of post-test level of postural health (practice & pain) among experimental group of school children with their selected demographic variables (n=80)

Conclusion
The study revealed that Ergonomic Health Promotion programme supports positive benefits in reducing musculoskeletal symptoms. It also increases the exercise frequency and helps lead a healthy life and improve academic performance among school children.