Schroth and Pilates for Adolescent Idiopathic Scoliosis

Vital Capacity (VC) will be assessed using a COSMED microQuark PC spirometer (Rome, Italy). During the assessment, participants will be seated comfortably in an upright position. A nose clip will be applied to prevent airflow through the nose during the test. VC values will be interpreted by comparing the measured values with the predicted reference values obtained from healthy individuals.

Forced Vital Capacity (FVC) will be assessed using a COSMED microQuark PC spirometer (Rome, Italy). During the assessment, participants will be seated comfortably in an upright position. A nose clip will be applied to prevent airflow through the nose during the test. FVC values will be interpreted by comparing the measured values with the predicted reference values obtained from healthy individuals.

Total Lung Capacity (TLC) will be assessed using a COSMED microQuark PC spirometer (Rome, Italy). During the assessment, participants will be seated comfortably in an upright position. A nose clip will be applied to prevent airflow through the nose during the test. TLC values will be interpreted by comparing the measured values with the predicted reference values obtained from healthy individuals.

Residual Volume (RV) will be assessed using a COSMED microQuark PC spirometer (Rome, Italy). During the assessment, participants will be seated comfortably in an upright position. A nose clip will be applied to prevent airflow through the nose during the test. RV values will be interpreted by comparing the measured values with the predicted reference values obtained from healthy individuals.

Forced Expiratory Volume in One Second (FEV₁) will be assessed using a COSMED microQuark PC spirometer (Rome, Italy). During the assessment, participants will be seated comfortably in an upright position. A nose clip will be applied to prevent airflow through the nose during the test. FEV₁ values will be interpreted by comparing the measured values with the predicted reference values obtained from healthy individuals.

Core muscle strength will be assessed using The Stabilizer Pressure Biofeedback Unit (Chattanooga Group Inc., USA) with the participant in the prone position. The pressure cuff of the Stabilizer unit will be placed horizontally beneath the abdominal region, with its lower edge aligned with the anterior superior iliac spines (ASIS). Participants will be instructed to take a deep breath, exhale, and gently draw the umbilicus toward the lumbar spine while maintaining normal breathing. After participants have been familiarized with the maneuver, the Stabilizer unit will be inflated to 70 mmHg. Participants will then be asked to repeat the maneuver and maintain the contraction for 10 seconds. The assessment will be performed three times, and the mean value will be recorded.

The device projects white light stripes (raster lines) onto the participant's back, and the three-dimensional shape of the back is reconstructed by analyzing the deformation of these projected lines. The resulting curved light patterns are captured by a camera, allowing a radiation-free and non-contact assessment of spinal alignment and posture.

During the assessment, participants will be instructed to stand in a relaxed and stationary position facing forward, with their back toward the camera, arms hanging freely at their sides, and feet positioned on the designated markers on the platform. The following postural parameters will be assessed: pelvic symmetry, shoulder and scapular alignment, vertebral rotation, thoracic kyphosis angle, and lumbar lordosis angle.

Trunk proprioception will be assessed using a dual digital inclinometer (ACUMAR™, Lafayette, IN, USA). Participants will stand barefoot on a firm surface with their feet shoulder-width apart. The inclinometer sensors will be placed over the T1 and S1 spinous processes, identified by palpation. Participants will perform 30° trunk flexion and 15° trunk extension with their eyes open, memorize each target position, return to the starting position, and then reproduce the target angle. Each measurement will be repeated three times. The difference between the target and reproduced angles will be recorded in degrees as the measure of trunk proprioception.

Trunk rotation will be assessed using a Baseline Scoliometer (Fabrication Enterprises, White Plains, NY, USA). Participants will stand upright with their feet together and parallel, facing forward. They will then be instructed to place their hands together and bend forward until the trunk is parallel to the floor while keeping the arms relaxed. Angle of trunk rotation (ATR) will be measured at the cervical, thoracic, and lumbar regions, and the values will be recorded

Pressure pain threshold will be assessed using a Baseline algometer (White Plains, NY, USA). The device applies pressure through a 1 cm² rubber tip, and the pressure at which pain is first perceived will be recorded in kg/cm² . Measurements will be performed bilaterally at points 2-3 cm lateral to the paravertebral muscles at the level of the participant's primary spinal curve. Before testing, pressure will be applied to a non-test area to familiarize participants with the procedure. Pressure will then be gradually increased until the participant indicates that the sensation has become painful by raising a hand. Three consecutive measurements, separated by 5-second intervals, will be obtained, and the mean value will be recorded.

Quality of life will be assessed using the Scoliosis Research Society-22 (SRS-22) questionnaire. The Turkish validity and reliability of the questionnaire were established by Alanay et al. (2005). The SRS-22 consists of 22 items organized into five domains: pain, self-image/appearance, function/activity, mental health, and satisfaction with treatment. Each item is scored on a 5-point Likert scale, with higher scores indicating better quality of life. Permission to use the questionnaire will be obtained following ethics committee approval.

Perceived cosmetic deformity will be assessed using the Walter Reed Visual Assessment Scale (WRVAS). The Turkish validity and reliability of the scale were established by Çolak et al. (2020). The WRVAS is a visual instrument developed to evaluate how individuals with adolescent idiopathic scoliosis perceive their own deformity. It consists of seven items assessing spinal deformity, rib prominence, lumbar prominence, thoracic deformity, trunk imbalance, shoulder asymmetry, and scapular asymmetry. Each item includes five illustrations representing increasing deformity severity and is scored from 1 to 5, with higher scores indicating greater perceived deformity. The questionnaire will be completed separately by the physiotherapist, the participant, and a parent before and after the intervention. Permission to use the scale will be obtained following ethics committee approval.