1.    Introduction
Improper physical movements or prolonged unfavorable positions in teenage girls can lead to postural abnormalities, consequently affecting various body systems, including the skeletal-muscular system, and resulting in complications such as pain and postural abnormalities (1). Adolescents aged 12–15 years are particularly susceptible to movement disorders and skeletal-muscular abnormalities due to rapid growth and the onset of puberty, making it necessary to identify and develop suitable protocols to address these issues (2). The NASM approach is one of the corrective and applied methodologies utilized by many researchers for corrective exercises. Given the imperative to investigate the efficacy of these exercises in correcting functional disorders of the lower limbs and stature abnormalities, and the lack of similar studies on their effects specifically on female students, it becomes necessary to conduct research examining this exercise approach. Hence, this study aims to explore the impact of 8 weeks of corrective exercises utilizing the NASM approach on movement disorders, lumbar lordosis, and genu valgum in girls aged 12–15 years.
2.    Methods
The present research employed semi-experimental methods and falls under the category of applied research. The statistical population comprised 45 girls aged 12–15, selected based on criteria including movement disorders, lumbar lordosis, and genu valgum. The subjects were chosen through convenience sampling and divided into three groups: those with movement disorders (15 individuals), those with lumbar lordosis (15 individuals), and those with genu valgum (15 individuals). Criteria for inclusion in the movement disorder group involved observation of low back arches, knees moving inward, and feet flattening during the overhead squat assessment. For the genu valgum group, inclusion criteria consisted of a Q angle exceeding 17 degrees and a distance greater than 2.5 cm between the two medial malleoli of the ankles. Regarding the lumbar lordosis group, a lumbar angle exceeding 45 degrees served as the criterion for inclusion in the study. Movement disorders were identified using the overhead squat test. The degree of lumbar spine curvature was measured using a non-invasive method employing a flexible ruler measuring 30 cm. Deformities related to genu valgum were measured using a bone caliper manufactured in Iran with an accuracy of 0.1 cm, while the Q angle was measured using a universal goniometer manufactured in Japan with an accuracy of 0.1 degrees. The exercise protocol adopted was based on the American National Academy of Sports Medicine (NASM), comprising four stages: myofascial tissue inhibition techniques, lengthening, activation exercises, and integration exercises, aimed at addressing movement disorders, lumbar lordosis, and genu valgum in the subjects. Training sessions were conducted over a period of 8 weeks, with each session lasting 45 to 60 minutes, three times per week. Normality of the data was assessed using the Shapiro-Wilk method. Data analysis was performed using SPSS software version 24, employing inferential statistical methods including parametric dependent t-tests and non-parametric U-Mann-Whitney tests, with all analyses conducted at a significance level of P<0.05.
3.    Results
The results indicate the impact of 8 weeks of training utilizing the NASM approach on several parameters, including the lumbar lordosis angle, Q angle, distance between the two medial malleoli of the ankles, and assessment of movement disorders from anterior, lateral, and posterior views during overhead squat movement. As depicted in Table 1, the training demonstrated a significant improvement in both the lumbar lordosis angle (p = 0.011) and Q angle (p = 0.032), although it did not yield a substantial effect on the distance between the two medial malleoli (p = 0.086). Furthermore, the findings revealed the effects of 12 weeks of corrective exercise employing the NASM approach on movement disorders observed from various perspectives. Specifically, from the anterior view, significant improvements were noted in feet flattening of the right foot (p = 0.02) and inward movement of the right (p = 0.01) and left (p = 0.03) knees. In the lateral view, notable enhancements were observed in low back arches (p = 0.01). Additionally, from the posterior view, significant improvements were observed in feet flattening (p = 0.01) and asymmetrical weight shifting to the right (p = 0.01) and left (p = 0.02).

4.    Conclusion
The prevalence of functional disorders and abnormalities in the skeletal and muscular systems is relatively high among teenagers. Corrective exercise is frequently utilized to alleviate the physical complications associated with these conditions. This study endeavors to assess the efficacy of corrective exercises, employing the NASM approach, in mitigating functional disorders, lumbar lordosis, and genu valgum in girls aged 12-15. According to the research findings, it appears that engaging in exercises utilizing the NASM approach leads to the mitigation and reduction of the lumbar lordosis angle, correction of genu valgum in static evaluation, and reduction of dynamic movement disorders such as low back arches, asymmetrical weight shifting, knees moving inward, and feet flattening in girls within this age group. Considering the ages of the subjects (12–15), integrating this training protocol into schools' sports and extracurricular programs could potentially diminish the incidence and progression of musculoskeletal injuries among students.

Ethical Considerations
Compliance with ethical guidelines
There were no ethical considerations to be addressed in this research.
Funding
This research did not receive any grants from funding agencies in the public, commercial, or non-profit sectors.
Authors' contributions
All authors contributed equally to preparing the article.
Conflicts of interest
The authors declared no conflict of interest.