Spasticity and rigidity are two common types of abnormal muscle behavior seen among patients with neurological disorders (e.g., stroke, Parkinson’s Disease). Clinical assessment of increased muscle resistance during passive movement, or hypertonicity, involves qualitative and subjective scales such as the Modified Ashworth Scale (MAS) for spasticity or the Unified Parkinson’s Disease Rating Scale (UPDRS) for rigidity. Inaccurate and inconsistent assessments may occur depending on the rater’s level of experience and scale interpretation. Recently, researchers have been developing medical training simulators that mimic hypertonicity to aid the training of these clinician learners. However, there is a lack of quantitative data representing the kinetic and kinematic characteristics of these abnormal muscle behaviors. Thus, we developed a portable measurement device (the PVRM – Position, Velocity, and Resistance Meter) that measures the joint angle, velocity, and muscle resistance of the upper-arm extensor and flexor muscles. In Study 1, the accuracy and reliability of the PVRM was validated by comparing its measurements to a commercial dynamometer (Biodex), a gold standard for measuring biomechanical data. The PVRM measurements were similar to the gold standard Biodex measurements during the passive flexion movement, since the residuals for all measurements were between 1-13%. Therefore, the PVRM was able to quantify behavioral features of spasticity (e.g., catch-release behavior), rigidity (e.g., uniformly elevated muscle tone), and healthy (e.g., no muscle resistance) subjects. In Study 2, we conducted a clinical study of 38 participants using the validated PVRM to establish a database quantifying different levels of spasticity (n=15, MAS 1- 4);​ rigidity (n=11, UPDRS 1-3), and normal healthy (n=12) behavior of the biceps and triceps during passive flexion and extension of the elbow. Spasticity subjects demonstrated stretch speed and MAS score dependent hypertonia marked by a catch-release behavior, resulting in a convex parabolic stretch speed profile. Rigidity subjects exhibited uniformly increased muscle tone that was dependent on UPDRS score but independent of stretch speed. The PVRM can provide a database for development of physical training simulators to realistically mimic hypertonicity and serve as a clinical measurement tool to reliably quantify the type and degree of hypertonicity.