Technologies that monitor human health, diagnose health problems, or contribute to the study of brain functions and translate them into commands in the pursuit of finding replacements for those who have lost limbs to improve their lives are techniquesworth studying. Today, the Neuroimaging technique functional near-infrared spectroscopy (fNIRS) has become one of the pioneering technologies in various applications, especially in the medical field, and this technology has gone through major events and attracted the attention of researchers for numerous and diverse studies. Considering recent indications for this method, a brief review highlights the state-of-the-art of this method and offers various recent uses of its directions toward clinical application scenarios, in particular in the field of artificial limbs and neurological rehabilitation. In addition, this review provides insight into the expected uses of this method shortly. The research methodology included the theory of fNIRS, its basic principles, systems, and its relationship with other neuroimaging methods considering contemporary scientific modernity. Among hundreds of scientific publications, the selection of popular and fruitful research and articles related to the subject of review and their analysis led to beneficial results. Monitoring, diagnosing, and finding solutions to physical problems may fall a great deal on the responsibility of this technique, which is still in the circle of modern scientific research that has yielded discoveries even at the expense of the challenges it faces by combining it with another technology to fill its inherent flaw, which means encouraging the expansion of future studies of this technology, which may be the most promising technology for several clinical applications shortly.