The study and modelling of human movement requires accurate measurement of forces and of kinematic quantities, with proper control and monitoring of measurement uncertainty. The metrological aspects of such experimentation are often overlooked in the biomechanical literature. In contrast, we present here a complete measurement system that combines a double force platform with vision and inertial sensors, with some degree of instrumental redundancy, which permits a cross-validation of different measuring channels. Therefore, the system permits the characterization of a person's movement, enabling, at the same time, the verification of the acquired experimental data. Details are provided on the system and on the measurement procedure, in order that experimentation can be reproduced, if needed, in other laboratories. Then, as a test case, the experimental study of hopping is considered. Experimental results are discussed, with special focus on kinematic quantities, and system performance is discussed, by properly accounting for uncertainty issues.