Various previous studies showed that there is involvement of multifidus muscle in lower back pain patients. Atrophy of lumbar multifidus is commonly witnessed among LBP patients. However, there is a lack of scientific findings regarding the training of this muscle. It is still unknown what changes are caused in the multifidus by such training methods. Therefore, the aim of this review is to explore the impact of various training techniques on the thickness of the multifidus muscle in patients with chronic or nonspecific back pain. Various international databases like Google Scholar, Scopus Elsevi¬er, Web of Science, and PubMed were searched by using a combination of keywords like “Exercise”, “Multifidus”, “Thickness” and “Lower Back Pain”. PEDro scoring was used for the assessment of the quality of included RCTs in the present review. It was found that there are few studies that showed improvement in the thickness of lumbar muscles due to different types of training but without investigating lumbar multifidus specifically. Isokinetic training and core stabilization exercises have been found to improve the thickness and symmetry of the multifidus muscle, as well as aid in muscle atrophy recovery. Isokinetic exercises and core-strengthening routines have been shown to enhance the multifidus muscle’s thickness and symmetry, and also assist in reversing muscle atrophy. It can be used to improve the knowledge of physical therapists and LBP patients who are suffering from chronic or nonspecific back pain.