Abstract: Low back pain (LBP) represents an immense economic burden, with a lifetime prevalence of up to 84 %. However, conventional diagnostic methods such as MRI or X-rays provide only limited information about the pathogenesis and specific pain-related functional limitations. Wearable inertial sensors (IMU) and electromyography sensors (EMG) offer an expanded spectrum for the targeted identification and diagnosis of LBP. The aim of the study is to evaluate a selective diagnostic series for the subcategorization of functional deficits and their precise assignment to specific functional deficits. Based on a systematic literature review, an objectively measurable functional LBP assessment was defined that tests fatigue resistance, neuromuscular control, lumbopelvic stability, and global trunk musculature. Subsequently, 38 individuals were recruited in a prospective cross-sectional study and divided into three groups: “healthy,” “mild pain,” and “severe pain.” These individuals underwent an assessment. The two pain groups differed significantly from the symptom-free individuals in all previously defined functional levels. In addition, the two pain groups also differed significantly from each other. The functional assessment, which incorporates IMUs and EMG sensors as a central diagnostic element, is so valuable because it can identify causal relationships between mechanical dysfunctions and the underlying neuromuscular cause, thus enabling individualized therapy.