I am using a Biodex System 3 to measure plantar and dorsiflexion over a small range of motion (~20 degrees) at a high rate of speed and LabView to collect the data. I need my participants to produce a predefined isometric torque at a specific angle before initiating a high velocity eccentric contraction into dorsiflexion, but as my participants press against the footrest into plantarflexion creating the necessary isometric torque (even as low as 25 Nm), the footrest slips to extend the range of motion beyond where its preset value is before the eccentric contraction starts. I need the footrest to remain stationary until I press the start button on the Biodex panel to initiate the isokinetic mode (or any other mode that will produce the same effect) to begin the eccentric portion of the measurement. Has anyone else had a similar issue as this? I am unsure if this problem is isolated to my particular Biodex or if the problem is more widespread. Thank you for your help and suggestions!