I have been using force platforms for more than 38 years to test a huge range of athletes from children to elite, healthy elderly and numerous clinical populations. I have worked with NBA, NFL, US Ski and Snowboard, NCAA Division 1, and national representative level athletes from Australia, England, Scotland, The Netherlands, Japan, USA, Malaysia, Sri Lanka, China. In fact my PhD which I completed in 1998 was titled “Expression and Development of Maximal Muscle Power” for which force platforms were used for every experiment.
While I have used multiple third party systems from Kistler, AMTI, and Bertec over the years I have also been involved in the design and development of specialised force platforms for performance testing and training. I have used single and dual platform systems.
Declaration of conflict of interest – I receive royalties from companies selling both single and dual platform systems. In addition, Innervations sells both single and dual platform systems.
There are advantages and disadvantages for each approach. Personally I prefer to use a single platform capable of four individual force measurements corresponding to each corner of the platform. The dual platform systems for performance application currently on the market only produce a single “summed” force signal from each plate. While this provides very good separation of vertical force exerted on the left and right platforms, it is not possible to determine the actual position of the centre of pressure (COP), a critical biomechanical parameter for assessment of balance, stability and functional movement performance. For example,
It is a misconception that dual platforms are required to measure left to right symmetry. A single platform with 4 force signals can provide a wealth of symmetry information not only in the mediolateral (left to right) plane but also anterior posterior plane. Here is one example of symmetry analysis of a countermovement jump using a single force platform.
To explain the biomechanics of force, COP and symmetry measurement using single versus dual platform systems I created a computer model in Excel and produced this video.
Dr Rob Newton, PhD, CSCS*D