What is it?
Basically it is the knee dropping in sideways. You can usually see this when someone is doing squats, lunges and any sort of gait pattern.
Why does it happen?
It can be for a couple of reasons. Sometimes your abductors can be too tight or overactive, these are the muscles running on the inside of the leg. On the other side, it could be the muscles at the top of the leg/glute area or your TFL or ITB that could be a bit weak and aren’t pulling that leg around in the normal stride. Or it could just be your natural biomechanics!
What do we do to change that?
This all depends on the above question to how we go about this. It could be by strengthening those glute muscles with exercises such as clams, crab walks, and sidekicks. Stretching the inside of your leg, so doing your leg stretches every day to help loosen those areas up!