This disclosure relates to a system and method to evaluate movement disorders. A movement data aggregator can combine data from a plurality of sensors into an aggregate movement data describing multi-dimensional movement of a handheld device. A calculator to compute an indication of a movement disorder based on the movement vector data and user input data, the user input data being generated in response to physical interaction between the handheld device and a human machine interface of a computing device/machine that is separate from the handheld device. In some examples, the handheld device can communicate with computing device via a wireless interface.