If you've had serious knee injury, turning like in the first video is a guaranteed pain for the rest of your day in your knee. It puts compression and torsion in your knee at the same time, like grinding up herbs on a cooking show.
Torsion and compression are a great way to ruin joints so.
Source: My Orthodontist after looking at my right knee (nodules) and left one (ligaments and torsion / compression at the same time)
Edit: Orthopedist, not dentist! What was I thinking!
that's a meniscus, and coats the articulating surfaces (called condyles). synovial fluid in the joint capsule acts as a lubricant for the menisci.
a nodule is a lump.
Yes, yes, totally agree…
> like grinding up herbs on a cooking show.
Wut???