This work details a virtual-reality (VR) system developed to evaluate alterations in hand movements and central rhythm formation in Parkinsonian and elderly subjects. One feature of VR systems that is essential for use in clinical evaluation and to warrant presence is the lack of behavioral distortion from real-world execution. Herein, we present a technical description of our VR and its validation to evaluate rhythmic motor patterns when experimental subjects perform a finger tapping test. Execution of the test was performed at different rates in the VR system, and compared to the gold-standard real-world testing. The VR system proved to be as valid and reliable as real-world testing to characterize arrythmokinetic profiles present in Parkinsonian and elderly subjects (compared to young subjects), at the different rates of execution. VR served as a complementary tool in a research setting to isolate subjects from unnaturalistic environments during clinical evaluation, such as labrooms or brain scans, since it did not bias behavior from real-world evaluation in a basic clinical test.