Inclusion Criteria:  Adults aged 18 and over willing to attend the study. For those who join the thoracic kyphosis group, individuals with a kyphosis angle ≥ 40 degrees. Individuals with a kyphosis angle < 40 degrees for the control group.  Exclusion Criteria:  Spine trauma, surgery, bone pathology, arthritis etc. have a history of illness Kyphotic deformity types are rounded back, Scheuermann's disease, hunched back, flat back and Dowager hump. Any spinal deformity, bone abnormality, postural deformity and disc herniation with / without peripheral symptoms. Body mass index (BMI), which is an indicator of obesity, is more than > 30. Complaining of balance problems, coordination problems, other neurological or vestibular diseases that affect body balance and posture. Having any orthopedic or neurological disease that affects the body joints or the integrity of the musculoskeletal system. Use of any medication that can cause dizziness or drowsiness in the last months.