A Comparison of the Effects of Exercise Methods for Adolescent Hyperkyphosis on the Sensorimotor System

This group will perform a kyphosis-specific Schroth exercise program focused on active thoracic posture correction, axial elongation, and corrective breathing. Participants will practice the exercises at home, using a mirror for visual feedback and tactile cues to monitor their posture.

Participants will perform the program at home 3 days per week for 8 weeks, with each session lasting approximately 45 minutes, including a 5-minute warm-up and a 3-minute cool-down. Three face-to-face training sessions will be provided during week 1, followed by face-to-face follow-up visits at the beginning of weeks 3 and 5. The program will have two stages. Participants who meet the prespecified progression criteria will advance to stage 2 at the week 5 follow-up.

This group will perform a conventional exercise program including stretching, scapular retraction, back extensor and trapezius strengthening, and trunk stabilization. The program will not include Schroth-specific active posture correction, corrective breathing, or mirror-based posture feedback.

Participants will perform the program at home 3 days per week for 8 weeks, with each session lasting approximately 45 minutes, including a 5-minute warm-up and a 3-minute cool-down. Three face-to-face training sessions will be provided during week 1, followed by face-to-face follow-up visits at the beginning of weeks 3 and 5. The program will have two stages. Participants who meet the prespecified progression criteria will advance to stage 2 at the week 5 follow-up.

Thoracic position sense will be assessed with dual digital inclinometers placed at T1 and T12. With eyes closed, participants will reproduce a 15° thoracic extension target. The primary measure is the mean absolute difference between the target and reproduced angles across five trials, in degrees; lower values indicate smaller error. Flexion (30°) and right and left lateral flexion (20°) will also be measured as secondary directional outcomes.

Balance will be assessed with the AI Balance system using the modified Clinical Test of Sensory Interaction on Balance (four eyes-open/eyes-closed conditions on firm and foam surfaces; three 30-second trials per condition) and the Limits of Stability test (weight shifting toward eight targets). Higher sway index values indicate greater sway; higher Limits of Stability scores indicate better performance.

Thoracic curvature will be measured with a Flexicurve ruler from C7 to T12. The kyphosis index will be calculated as the kyphosis apex depth divided by the curve length, multiplied by 100. The values above 13 indicate hyperkyphosis.

Sagittal posture will be assessed from a lateral photograph using the PostureScreen Mobile application. Landmark displacement will be recorded in centimeters under standardized camera, posture, clothing, and hair conditions.

Isometric strength of the trunk flexors and extensors, upper, middle, and lower trapezius, and serratus anterior will be measured using a hand-held dynamometer and the make-test method. Three 5-second contractions will be performed for each muscle group. Mean force will be normalized to body weight and reported in N/kg.

Hamstring and lower-back flexibility will be measured with the sit-and-reach test; the maximum distance across three trials will be recorded in centimeters. Pectoralis minor muscle length will be measured bilaterally with a tape measure; the mean of three measurements will be analyzed.

Scapular, trunk flexor, and trunk extensor endurance will be assessed using the isometric scapular endurance, McGill trunk flexor endurance, and Biering-Sørensen tests, respectively. The time each position is maintained without compensation will be recorded in seconds. Each test will be performed once, with at least 5 minutes of rest between tests.

Resting, activity-related, and nocturnal spinal pain during the previous week will be rated on a 0-10 cm Visual Analog Scale, where 0 indicates no pain and 10 indicates the worst possible pain.

Deformity perception will be assessed with the Turkish version of the Kyphosis-Specific Spinal Appearance Questionnaire. The 10-item questionnaire is scored from 1 to 5; the mean item score will be analyzed. Higher scores indicate a more negative perception of spinal appearance.

Overall perceived change will be assessed using the 7-point Global Rating of Change scale, from -3 (much worse) to +3 (much better), with 0 indicating no change. Scores of +2 or +3 will indicate a clinically meaningful perceived improvement.