I wish to purchase a force platform for postural research and would appreciate any answers to the following questions.

As I understand it, Kistler use piezoelectric transducers, whereas AMTI and others use strain gauges. Theoretically, the former are better for measuring transient forces, and the latter are better for long term recordings. I wish to make continuous recordings over minutes, and so based on this logic I should choose a strain-guage device. However, I would like to know if anyone has direct experience of the drift characteristics of these different plates. Specifically, are AMTI/Bertec better than Kistler for drift? Is there a direct trade-off between accuracy and drift when choosing a forceplate?

Also, Kistler now make very light-weight (~10kg) portable force platforms. Theoretically, low weight is not good because it reduces the resonant frequency. Does anyone have experience with these new platforms, and do they provide decent signals for standing subjects?

Any advice appreciated.

Raymond Reynolds
Lecturer in Motor Control
School of Sports & Exercise Sciences
College of Life & Environmental Sciences
University of Birmingham, B15 2TT
0121 414 4107