Force Plates Data Acquisition Equipment
The School owns two AMTI Force platforms
A force transducer allows forces exerted on a body to be measured. Although there are many types of transducers they all work under the same principle - a force applied to the transducer causes an electrical signal proportional to the applied force.
AMTI force plates simultaneously measure three force components along the x, y, and z axes and three moment components about the x, y, and z axes. The forces and moments are measured by foil strain gauges attached to load cells at the four corners of the platform. The gauges form six Wheatstone bridges (Figure 1) having four active arms each with eight or more gauges per bridge. Three of the output voltages are proportional to force and three are proportional to moment.
Figure 1. Wheatstone Bridge circuit diagram.
The output of the force plates are then sent to a high-gain amplifier, which provide excitation and amplification for each channel of the force plate. The output from the amplifiers can then be fed into an analog to digital converter (A/D converter). The A/D converter is used to store the incoming data in a digital form (numbers in a computer file) which can then be used by the researcher.
For further information on Force Plates please refer to David Winter's Biomechanics of Human Movement.