Skyler Tanner on TSC or timed static contractions on ARX Professional motorized equipment (same company that produces the Omni, but significantly different model).
This is a great video for learning about TSC.
You can see me doing my own spin on a timed static contraction for the belt squat here.
Note : I no longer use the stability ball as a safety measure. That was strictly used because of how early in my rehab I was then (and how tight my MPFL was then).