Introduction: Lower back pain affects about 65–80% of population in highly developed countries. The main causes include sedentary lifestyle and limited physical activity. Certain overloads of the spine and sacroiliac joints are considered to account for most cases of spinal pain. The aim of the study was to perform a comparative analysis of the efficacy of segmental stabilisation exercises and post-isometric relaxation vs. exercises restoring balance of spinal muscular tension in combination with post-isometric relaxation. Material and methods: A total of 100 patients diagnosed with chronic lumbar overload pain syndrome were included in the study group. Participants were randomly classified into two same-size groups, which received a 2-week selective manual therapy in an outpatient setting. The study used (before and after the 2-week rehabilitation process) Visual Analogue Scale, Low Back Pain Rating Scale, Oswestry Low Back Pain Disability Questionnaire and Roland Morris Disability Questionnaire, Schober’s test, test assessing spinal muscle strength and overall mobility test. Results: Based on the observations, reduced lumbar pain was shown after the use of both rehabilitation methods. There was also a decrease in the number of patients receiving analgesics. Improvement in the functional status, spinal muscle strength parameters, lumbar mobility and overall physical fitness was observed in all patients. Conclusions: Segmental stabilisation exercises improve spinal muscular strength parameters and lumbar mobility to a greater extent than exercises restoring balance of spinal muscular tension, which in turn have a greater impact on the decrease in the number of patients receiving analgesics.