Abstract: A portable system for dynamometry, exercise, and rehabilitation comprises a base, a detachable servomotor assembly, an embedded control system, and a physical human-machine interface for securing a human limb into a stabilized position for use in a repeatable and ambidextrous manner. In another embodiment, the portable system includes a power source and a user interface subsystem for selecting operative modes and input parameters and for real-time processing, display, and storage of the values collected by the system during operation. In another embodiment, a method for determining strength of an isolated muscle group of a human joint is disclosed. The method includes the steps of mounting and securing a detachable servomotor assembly of a portable dynamometer upon a surface and securing the human joint to be tested into a stable position with an adjustable, ambidextrous distal limb attachment assembly for use of the portable dynamometer in a readily repeatable manner.