Hi, thanks for the question! Previous research by our team has shown that TrA activation increases as amplitude (and therefore footpath length) increased. It is discussed in 'The influence of foot-movement amplitude, during exercise on a Functional Re-adaptive Exercise Device, on deep spinal muscle recruitment and movement control' by Winnard et al. 2017

Thanks .it makes sense. So you are just using simple elliptical machine, correct?

How did you provide instability( pertubation) .Did you you specific planes of motion on XYZ , spesific amplitud etc...

dont you think that if simultaneous perubation tomthe foot was added it wouldvalso increase tva/m activation?

thank you. I think this is very useful and practical study

FRED is a heavily modified elliptical cross-trainer. The bearings are almost friction-less, so we don't add any specific perturbations to the exercise, the whole system is inherently unstable and requires co-ordinated muscle control to maintain a stable posture.

Is FRED abailable commercially?