Big shout out to Scot Morrison who educated me on this topic of torque or force steadiness. I showed this countermovement jump signal in a previous post of an ACL injured athlete, who after 12 months still had this atypical jagged signal in the unweighting phase of the jump, both bilaterally and unilaterally in both legs, as shown in the boxed region in the Figure on the left. When you magnify a force signal you will see it fluctuating around an average value, the standard deviation of which can be used as a measure of steadiness. However, the normal force signal during the unweighting phase is typically smooth as in the Figure on the right.

I hadn’t really thought of using the jump signal to get a measure of steadiness and motor control/proficiency, however, it makes perfect sense that this is another factor we should be considering in the return to work/play of client/athletes. This area of steadiness is studied a lot when comparing the old with the young, however, in terms of the injured and return to work/play not so much it seems.

Scot has been keeping an eye on it during isometric exercise in the clinic. Is anybody else using or quantifying steadiness in some manner to inform your diagnosis, or has some insights they would like to share?