As of 2018, Canada has legalized cannabis nationally, while 63% and 21% of the U.S. population lives in a state with legal access to medical and recreational cannabis, respectively. In this legal context, sales of highly concentrated cannabis (with tetrahydrocannabinol potencies up to 90%), have increased dramatically, sparking concerns on the public health and safety impacts. Acute effects from concentrates (often inhaled by “dabbing” or vaping) on motor function have not been described. To assess acute impairment under the influence of concentrates, we developed a motor battery measuring general and driving-related neuromotor function (e.g., standing balance, arm reaction time, finger tapping rate) with a novel smartphone application. Experienced concentrate users were assessed on the motor battery in a mobile laboratory: before, immediately after, and 1-hour after self-administering concentrated cannabis. Performance in standing balance, finger tapping, and reaction time changed before, immediately after, or one hour after smoking and with eyes open, closed, or with the head tilted back. This suggests that recovery time from intoxication and proprioception influence concentrated cannabis motor effects. Results encourage further research on the impact of concentrated cannabis on driving ability and for public health applications in roadside testing.