DNS: Face-to-face and Telerehabilitation

Pulmonary function will be assessed in the sitting position using a portable spirometer (Cosmed Pony FX, Italy) in accordance with the American Thoracic Society (ATS) guidelines. Before the test, participants will be instructed to wear loose and comfortable clothing and to avoid heavy meals immediately before the assessment. Participants will also be advised to temporarily discontinue specific inhaled medications if instructed by their physician. For the test, participants will sit in an upright position and will be fitted with a nose clip. They will place their lips tightly around a disposable mouthpiece connected to the spirometer. After taking a maximal deep inspiration, participants will be instructed to exhale into the mouthpiece as forcefully and rapidly as possible until complete expiration.

Pulmonary function will be assessed in the sitting position using a portable spirometer (Cosmed Pony FX, Italy) in accordance with the American Thoracic Society (ATS) guidelines. Before the test, participants will be instructed to wear loose and comfortable clothing and to avoid heavy meals immediately before the assessment. Participants will also be advised to temporarily discontinue specific inhaled medications if instructed by their physician. For the test, participants will sit in an upright position and will be fitted with a nose clip. They will place their lips tightly around a disposable mouthpiece connected to the spirometer. After taking a maximal deep inspiration, participants will be instructed to exhale into the mouthpiece as forcefully and rapidly as possible until complete expiration.

Pulmonary function will be assessed in the sitting position using a portable spirometer (Cosmed Pony FX, Italy) in accordance with the American Thoracic Society (ATS) guidelines. Before the test, participants will be instructed to wear loose and comfortable clothing and to avoid heavy meals immediately before the assessment. Participants will also be advised to temporarily discontinue specific inhaled medications if instructed by their physician. For the test, participants will sit in an upright position and will be fitted with a nose clip. They will place their lips tightly around a disposable mouthpiece connected to the spirometer. After taking a maximal deep inspiration, participants will be instructed to exhale into the mouthpiece as forcefully and rapidly as possible until complete expiration.

Dynamic balance will be assessed using the Y-Balance Test. Four measuring tapes will be positioned on the floor to form intersecting lines, creating a star-shaped grid with 45° angles. Only three directions will be tested: anterior (A), posteromedial (PM), and posterolateral (PL). Participants will place their dominant foot at the center of the grid while reaching as far as possible with the opposite foot in the specified directions. The plantar surface of the first metatarsophalangeal joint of the stance foot will be required to remain at the grid center to ensure consistency. Testing will begin in the anterior direction and proceed clockwise. During posterolateral reaching tasks, participants will be instructed to reach behind the stance leg. Each participant will perform three practice trials followed by three test trials in each direction. The average of the three test trials will be recorded as the test score. To account for limb length differences, normalized reach distance will

Trunk extensor endurance will be assessed using the Biering-Sørensen Test. Participants will be positioned prone on a treatment table with their anterior superior iliac spines aligned with the table edge, allowing the upper body to extend beyond the edge. Stabilization straps will be applied across the pelvis, thighs, and lower legs to secure participants to the table. With arms crossed over the chest, participants will be instructed to lift their trunk until it is parallel to the floor. A digital inclinometer will be placed between the scapulae to monitor trunk angle. Participants will be asked to maintain this horizontal position for as long as possible. The holding time will be recorded with a stopwatch. The test will be terminated when the trunk angle deviates more than 10° from the starting position or when the participant voluntarily stops.

Trunk flexor will be assessed using the Trunk Flexor Test. Participants will be positioned with the trunk at 60° of flexion, while the hips and knees are maintained at 90° of flexion. The arms will be crossed over the chest. Participants will be instructed to maintain this position for as long as possible. The test will be terminated when the participant can no longer hold the position. The duration (in seconds) will be recorded with a stopwatch.

Side plank will be assessed using the Side Plank Test on a mat, performed on the dominant side. Participants will extend their legs so that the knees and feet are aligned. While lifting the hips off the mat, body weight will be supported only by the lower elbow and feet. The test will be terminated when the side plank position deteriorates or the hips drop. Test duration will be recorded in seconds.

Postural alignment will be assessed using the PostureScreen Mobile® application (PostureCo; http://postureanalysis.com/mobile/). Participants will stand in a neutral position while photographs are captured from anterior, posterior (coronal plane) and lateral (sagittal plane) views. The application provides an on-screen target to ensure consistent image capture. Digitization will be performed by overlaying a grid on each image, allowing calculation of postural angles and assessment of body segment alignment relative to neutral posture. Output will include quantified postural variables and annotated images.

Deep Stabilization System (DSS) function will be assessed by a certified physiotherapist through palpation and visual observation. Six DSS tests will be administered in a fixed order: diaphragm, trunk flexion, back extension, hip flexion, intra-abdominal pressure, and side plank. Each test will be scored on a 5-point scale (1 = adequate activation; 5 = inadequate function). Tests will be repeated twice, and the consistent score will be used for analysis.

Diaphragm Test: Participant seated upright with arms and legs relaxed; instructed to perform deep inhalation while the physiotherapist palpates laterodorsal regions of the abdominal wall and observes lateral rib movement.

Trunk Flexion Test: Participant supine with arms relaxed alongside the body; instructed to flex the neck and trunk until the inferior angles of the scapulae lift off the table. Trunk and chest muscle activation will be visually assessed.

Back Extension Test: Participant prone with

Participant satisfaction with the intervention will be assessed at the end of the study using the Treatment Satisfection scale. The Treatment Satisfection is a patient-reported outcome measure that captures perceived changes in health status over time. In this study, a 7-point scale ranging from -3 to +3 will be used, where -3 indicates "much worse," 0 indicates "no change," and +3 indicates "completely recovered."