Biomechanical analysis of human movement supports rehabilitation decisions requiring objective and reproducible measurements. However, motion capture technologies are commonly evaluated as separate technological families. This critical review compares marker-based optoelectronic, markerless, inertial, and hybrid systems in terms of accuracy, clinical validity, reliability, and implementation feasibility, and proposes methodological criteria for future validation studies. Scopus, Web of Science, PubMed, and IEEE Xplore were searched, supplemented by forward and backward citation searching from eight seed studies. The selection process was reported using a PRISMA 2020 flow diagram. No protocol was registered, and no formal risk-of-bias assessment was conducted. Eligible studies involved human participants in clinical, rehabilitation, or functional assessment settings and reported quantitative performance metrics. Evidence was synthesized by technological family and application scenario. Ninety-six documents were included. Marker-based systems provided the highest accuracy for joint kinematics, whereas markerless and inertial systems showed comparable validity for spatiotemporal variables and global movement characterization. However, errors in specific joint angles remained above clinically desirable thresholds. Calibration procedures and assessment duration substantially influenced performance. No technology was universally superior. Therefore, selection should be made by variable, task and population, using explicit validation criteria.