Using ecto's diagram, this is how I have a second platform to support the upper quad or thigh area as with the machine version. It's only to give you a rough idea but the second platform has to be...
Armwrestle lots of people who you think are stronger than you (humiliation), for fun and accept your limitations by giving up before your "breaking point" (haha). Otherwise, take it too seriously and...
Place barbell on sawhorses and load up with plates. Lift and move away from sawhorses, squat for reps then drop weight. Naturally, you need rubber plates and/or suitable floor area for drops. Edit:...
Yeah, I know... you're trying hard to say something like "Dynamic effort style or explosive Squat" but you've got crud on your tongue and cranial pain so you had to copy from an example model. ;)