Although abdominal muscle thickness has been evaluated in individuals with scoliosis in the literature, there is no study in the literature reporting the relationship between abdominal muscle thickness under ultrasound as a result of schroth exercises. The aim of this study is to evaluate the effectiveness of the Schroth method on abdominal muscle thickness in people with AIS.

Scoliosis is defined as the lateral curvature of the spine more than 10 degrees to the right or left, detected radiologically in the coronal plane, but scoliosis is a complex three-dimensional orthopedic deformity that also affects the spine, shoulder girdle and pelvis. The etiopathogenesis of scoliosis is still unclear and the cause cannot be determined in 80% of cases, and it is called idiopathic scoliosis. Other causes include neurological, bone origin, trauma, joint and connective tissue pathologies. Scoliosis causes postural changes in the whole body of the person due to the rotation and angulation of the spine. Especially the abdominal muscles, rib cage, back and waist extensors are most affected by this condition, and it causes biomechanical changes in the pelvis, shoulder girdle and even lower extremities and feet. The spine causes severe morphological changes due to vertebral wedging and rib cage distortion. Vertebral wedging causes a progressive vertebral deformation associated with axial rotation and scoliosis progression. This vertebral deformation is not only associated with the deterioration of the bone structure and the spine, but also causes changes in the structures of the upper extremity and lower extremity. In the treatment of scoliosis; There are four main categories as observation, corset, physiotherapy and rehabilitation applications and surgery. These treatments should be decided by considering the risk of curvature progression. The main purpose in the treatment of scoliosis is to prevent curvature progression. In scoliosis, besides the spine, shoulder girdle, trunk muscles, pelvis and even lower extremities are also affected by this pathological condition and postural problems occur. Therefore, a detailed clinical analysis and evaluation of the entire musculoskeletal system should be performed in individuals with scoliosis. The problem is determined by revealing in detail the length, strength and functional status of the muscles and ligaments that cause impaired body cosmetics. It has been reported in the literature that pelvic anomalies occur with the progression of scoliosis. Qui et al. reported that there is a difference between the right and left of the pelvis, which is not due to developmental asymmetry or distortion of the pelvis, but due to horizontal rotation. At the same time, Gum et al. reported that people with adolescent idiopathic scoliosis (AIS) have advanced pelvic rotations in the transverse plane. Panjabi et al. reported that the system model of the spine consists of passive, active and control subsystems. Any problem that may occur in these three systems is compensated by other systems responsible for carrying out coordinated activities. trunk muscles; especially the multifidus, transverse abdominus and internal obliques are examples of active systems. Contraction of these muscles plays an important role in trunk stabilization by increasing abdominal pressure and elongation of the thoracolumbar fascia. In the magnetic resonance imaging study conducted with people with AIS, changes were observed in the type 2 fibers of the multifidus muscle on the concave side of the apex of the curve. The European Society of Scoliosis Orthopedics and Rehabilitation (SOSORT) recommends scoliosis-specific exercises in addition to bracing for scoliosis. It has been reported that the progression of the curve is very rapid if there is a progression of 5.4 degrees and above in the measurements taken every 6 months for curves of 25 degrees and above and these people should be included in the treatment. Although bracing is a difficult treatment to accept in some children, the acceptance of exercise therapy is higher. Schroth exercises are specialized exercises for scoliosis and have been reported to reduce the Cobb angle of curvature, improve neuromotor control, increase respiratory function and back flexibility, and improve cosmetic appearance. The Schroth method includes scoliosis-specific sensorimotor, posture and breathing exercises, and provides the prevention of 3-dimensional spinal deformities in the spine by the formation of postural realignment in people with AIS. With the autocorrection included in the method, self-elongation and postural correction are provided to each curvature pattern and the person's muscle imbalance is balanced. It has been reported that with Schroth exercises, muscle strength and flexibility are increased, the Cobb angle is improved, and surgery rates are reduced. Kim et al., in their study in which they examined the abdominal muscle thickness under ultrasound in people with AIS, did not see a difference in transverse abdominus muscle activation between individuals with scoliosis and a healthy control group during rest, but they reported a significant difference between both groups during contraction. Although abdominal muscle thickness has been evaluated in individuals with scoliosis in the literature, there is no study in the literature reporting the relationship between abdominal muscle thickness under ultrasound as a result of schroth exercises. The aim of this study is to evaluate the effectiveness of the Schroth method on abdominal muscle thickness in people with AIS.

Inclusion Criteria:

• Having been diagnosed with idiopathic scoliosis by a specialist physician,
• 10-18 years old,
• The primary curvature is between 10-45 degrees according to the Cobb method,
• C or S scoliosis,
• Pain in the back/lumbar region due to scoliosis,
• Those who have not received any exercise therapy for scoliosis before,
• Volunteer to participate in the study,
• Having the cognitive capacity to cooperate with the guidance of the physiotherapist,
• Have not had any musculoskeletal injury in the last 6 months,
• No neurological, orthopedic or cardiopulmonary disorders other than the diagnosis of scoliosis,
• Young individuals who have not undergone any surgery related to the diagnosis of scoliosis will be included in the study.

Exclusion Criteria:

• The patient has any contraindications for exercise,
• Having had previous spine surgery and abdominal surgery,
• Having any mental problems,
• The fact that scoliosis is not idiopathic but has arisen for different reasons (neurological, congenital),
• In case of neurological, psychiatric, muscular, rheumatic or orthopedic diseases, these people will not be included in the study.