Inclusion Criteria:  Fifty patients with chronic low back pain or repeated non-specific back pain for more than three months. Both sex with posterior pelvic tilt (-0.7 ± 6.5°)and decreased lumbar lordosis, for (Group A) and normal anterior pelvic tilt angle between 5° and 13° for (Group B) Their ages were ranged from 20-35 years. Body Mass Index from 18-25 Kg/m² .  Exclusion Criteria:  Previous back surgery. Signs and symptoms of gross spinal instability. Radiological diagnosis of spondylolysis or spondylolisthesis. Acute low back pain. Disc prolapse or herniation. Any neurological, orthopedic, and vestibular disorders affecting the balance system. Flexion and extension restriction of the lumbar region. Other conditions that affected the normal functioning of the central and peripheral nervous system such as alcohol abuse, addiction, dementia, and cognitive disorders.