In this study, which aims to evaluate the respiratory functions and respiratory muscle strength of individuals with Adolescent Idiopathic Scoliosis (AIS), it is planned to investigate the relationship between the respiratory parameters obtained and the severity, type, location of the curvature, rotation angle and wearing brace.

The population of the study consists of individuals with AIS, and the sample consists of individuals with AIS followed in the Goztepe Prof. Dr. Suleyman Yalcin City Hospital, Orthopedics and Traumatology Clinic. For this purpose, it was planned to include at least 60 individuals with AIS, aged 10 years and older, with at least 20 degrees of scoliotic curvature, who applied to the clinic for the first time or came for control.

Pulmonary Function Tests (PFT) will be applied to evaluate the respiratory functions of the participants involved, and intraoral pressure measurement (MIP, MEP) will be applied to evaluate the inspiratory and expiratory muscle strengths; The severity of the scoliotic curvature will be measured with the Cobb method on the same day's radiograph, and the axial rotation angle will be measured with the Scoliometer.

IBM Statistical Package for Social Sciences Version 24 statistical program will be used in the analysis of the data. Continuous variables will be given as mean ± standard deviation, qualitative variables as numbers and percentages.

Pearson Correlation analysis will be used for the relationship between the variables, Independent Samples t-test will be used for the comparison of independent groups, and statistical significance will be taken as p≤0.05 in all measurements.

It is thought that this planned study will contribute to studies evaluating the respiratory functions and respiratory muscle strength of individuals with AIS, which have been designed in different types and reported different results in the literature.

Evidence-based data obtained by determining the clinical parameters associated with these values are expected to guide clinicians in terms of being holistic in the treatment of individuals with scoliosis, and in which situations and for what purpose pulmonary rehabilitation approaches should be included.

Scoliosis is a complex three-dimensional deformity characterized by a lateral deviation of the spine of at least 10 degrees in the coronal plane. Scoliosis, which develops due to many reasons, is called "Adolescent Idiopathic Scoliosis (AIS)" if it occurs in the period from the onset of puberty to the closure of the growth plates.

The main treatment options for scoliosis are; Known as observation, orthosis and surgical intervention, the choice of the most appropriate treatment depends on the patient's age, menarche status, location and size of the curvature, and risk of progression.

Scoliosis can cause a significant increase in respiratory workload by directly decreasing chest wall compliance and indirectly reducing lung compliance. Abnormal ventilation patterns, especially restrictive ventilatory disorders, are seen in individuals with AIS, especially in curves greater than 45°; Sagittal diameter of the thorax, total lung area and especially vertebral rotation at T8-T9 levels can affect respiratory functions. In a study, it was shown that patients with mild or moderate idiopathic scoliosis had significantly lower Forced Vital Capacity (FVC) values compared to healthy controls. On the other hand, in a recent study in which 30 individuals with scoliosis were included, FVC values were found to be low in only two cases, which was thought to be due to the fact that the curve intensities of the participants were mild (Cobb angle< 20ᴼ). In the literature, studies examining the relationship between location, type, angle of rotation, presence of brace and duration of use, apart from the severity of the curvature, and pulmonary functions in individuals with AIS are insufficient. Low FEV1 and FVC values were found in 19% of AIS patients who had pulmonary function test preoperatively, and individuals with high grade (Cobb angle > 70ᴼ) and wide main thoracic type curves were reported to be more affected. Although no significant results were obtained in the degree of axial rotation in the same study, it was observed that the rotation angles of the cases with low PFT parameters were higher. A different study reported that the size of the thoracic curve and the number of involved vertebrae were negatively correlated with pulmonary parameters in individuals with AIS, and that spirometric examination is necessary, especially in surgical planning. Although studies have shown that respiratory muscle strength of individuals with AIS is decreased compared to healthy controls, even with mild curvatures, the cause of muscle dysfunction is not known exactly and it is thought that several factors may affect muscle function (nutritional status, physical activity, systemic inflammation, etc.). In scoliosis, especially the distortion of the thorax, the placement of the diaphragm and intercostal muscles and affecting the force production can also reduce respiratory muscle strength. In a study, a weak correlation was found between the angular value of scoliosis and respiratory muscle strength in individuals with AIS, and it was reported that respiratory muscle strength may be associated with physical deconditioning. In individuals with a high progression rate and an indication for scoliosis surgery, decreased respiratory muscle strength before surgery may cause a serious increase in respiratory workload, causing the patient to be unable to extubat, and post-operative respiratory failure due to respiratory muscle weakness. Therefore, respiratory muscle strength and function levels are important in curves with a high progression rate and surgery is planned, and it is important to use methods that prevent and reduce respiratory muscle dysfunction.

In the literature, studies evaluating respiratory muscle strength and related parameters of individuals with AIS are very limited. In our study, it was aimed to measure the respiratory functions and respiratory muscle strength of individuals with AIS objectively and to investigate the relationship of these values with the severity of curvature, type, location, rotation angle and corset use. It is expected that the evidence-based data obtained will guide the treatment of individuals with scoliosis to be holistic and in which situations and for what purpose pulmonary rehabilitation approaches should be included.

Inclusion Criteria:

• Volunteer to participate in the study
• 10 years and older
• Having been diagnosed with Adolescent Idiopathic Scoliosis,
• At least 20 degrees of scoliotic curvature in the coronal plane

Exclusion Criteria:

• Individuals aged 9 and under, 20 years and over
• Individuals with neuromuscular and congenital scoliosis
• Individuals with pulmonary dysfunction due to a different pathology
• Individuals with a history of surgery
• Cases with mental retardation
• Individuals who do not understand, cannot apply, and cannot cooperate with respiratory tests

Cases with Adolescent Idiopathic Scoliosis followed in a Prof. Dr. Suleyman Yalcin City Hospital (Secondary health institution)