11/17/2025
We discussed lingering concentric phase impulse asymmetry in the double limb countermovement jump in our previous post. What about single leg countermovement jumps? What metrics do we find useful?
We plotted typical output metrics, jump height and mRSI against 2 metrics that we like from the braking (eccentric deceleration) phase. Remember from our last post, that braking is the “downward” phase of a jump.
A strategy, typical in an ACL reconstructed patient, is to reduce both the distance downward (countermovement depth) and speed (peak eccentric velocity) likely because the person has inadequate braking impulse needed to stop their momentum at the bottom of a squat at a depth similar to their non affected side. This is noted as the “stiff knee” strategy.
We can see that over time, the affected limb counter movement depth and eccentric peak velocity improves to values similar to the non affected side. Jump height and mRSI (more on mRSI later) as “outputs” are relatively similar, but achieved by different strategies and remain consistent deficits throughout all of rehab.
