Free standing platforms may work well for activities with relatively low frequency dynamic content, low impulse loading and low side loads such as balance and gait activities. Yet even for these activities care must be used to place the platform on a flat surface so that it does not rock or shake when loads are applied. If the platform rocks against a hard flooring surface, noise artifacts may be introduced into the data. Carpeted floors will generally work reasonably well as the compliance of the carpet distributes the load evenly between the platform and the floor. On hard surface floors, such as asphalt tile flooring, it is best to shim the platform under the mounting pads until no rocking is evident. This can be done using paper or scotch tape shims.
AMTI biomechanics force platforms are designed to measure forces and moments applied to their top surface and as a direct result these instruments are sensitive to accelerations as well. Building vibration and ground vibration can be transmitted to the platform and can result in unwanted signal noise. Heavy concrete construction or ground laid concrete slabs provide the best flooring situations.