Chronic low back pain (LBP), defined as back pain persisting for more than 12 weeks, affects over 50% of the general population.[1] It is the second most common factor for patients in search of primary care services.[2]According to the US National Center for Health Statistics, 14% of new patients admitted to a hospital for treatment had low back pain, representing 13 million people.[3] Also, it is estimated that over 70% of adults have had at least one episode of LBP in their lifetime.[4]In 2007, another study revealed that lower back region pain is caused by disc degeneration, spondylolisthesis, lumbar stenosis, epidural hematoma, and other causes, and 3% of all patients discharged from hospitals have symptomatic low back pain.[5] Because the causes of LBP are variable, different exercise regimens have been used to treat patients, including lumbar flexion, extension, isometric flexion, passive extension, and intensive dynamic back exercise regimens, and many of these exercise regimens have not yielded satisfactory results.[6]Recently, some studies have focused on exercises that aim to maintain or improve lumbar spine stability, such as lumbar stabilization exercises, which are aimed at improving the neuromuscular control, strength, and endurance of the muscles that are fundamental to maintaining spinal and trunk stability through several groups of muscles, particularly transverse abdominis and lumbar multifidi, but also other paraspinal, abdominal, diaphragmatic, and pelvic muscles.[7] Unsubstantiated suggestions that stabilization training may be useful in reducing pain and disability for all patients with nonspecific LBP, have appeared in the literature,[8] but these assertions have not been definitively demonstrated. Weakness of the abdominal muscles among the trunk muscles of low back pain patients is generally prevalent, and the strengthening of the abdominal muscles is essential in the recovery of the spinal neutral position.[9] When imbalance between the abdominal muscles of the trunk and extensor muscles occurs, it triggers slow back pain and reduces stabilization of the lumbar.[10]The ability to actively control the muscles of the hip plays an important part in lumbar segmental stability. If the sacroiliac joint moves excessively, it results in pressure on the joints and disks between the L5–S1 vertebral body, sacroiliac joint, and pubic symphysis, which leads to functional failure of the sacroiliac joint and low back pain. This causes the gluteus maximus muscle to contract, creating a self-locking mechanism, thereby providing stability to the sacroiliac joint.[11]There are various forms of exercise that can be prescribed based on different schools of thought, which include intensive dynamic back extensor exercises (motor control exercises), yoga and aerobic exercises.[12]Graded strengthening exercises are aimed at improving the neuromuscular control, strength, and endurance of the muscles that are central to maintaining dynamic spinal and trunk stability. The effect of graded lumbar stabilization exercises has been studied in subjects with recurrent LBP (8). Dynamic strengthening exercises can strengthen the spinal column and supporting structures.[13] An electromyography study to compare recruitment of the rectus abdominis and erector spinae muscles during dynamic strengthening exercise revealed higher muscle activity in these muscles.[14]Therefore, the aim of this study is to compare the effects of graded lumbar strengthening exercises and lumbar dynamic strengthening exercises on the maximal isometric contraction strength of the lumbar extensors, pain severity, and functional disability in patients with nonspecific chronic LBP. According to many studies, the first step of the physiotherapy treatment pyramid is education of the patient.[15] In another study, researchers explored several research studies that included evidence on conservative treatments,[16] which included manual therapy or conservative physiotherapy, which included exercises, mobilization, McKenzie approach treatment, manipulation, strengthening programs, advice, and other manual therapy techniques, which have strong evidence of effectiveness for chronic low back pain patients.[17] According to a study,[18] rest and exercise are effective for low back pain patients.