The evidence is very shaky on whether stretching works as we originally thought. It is relatively clear that while it can help alleviate pain & improve flexibility in the short-term, long-term effects are inconsistent. Static stretching also does not appear to meaningfully improve posture and it also hampers performance when taken too far. Dynamic stretching can have a place in a dynamic warm-up.
Knocked knees are a result of the body trying to find joint actions it is naturally missing in order to complete the gait cycle, or allow for full human movement. This comes at a cost of stressing tissues and joints around the pelvis and knee. To fix it, we should start with the root of the problem – the pelvis in Anteiror Tilt.
Breathing involves many joint actions at both the ribcage and pelvis. If you cannot breathe well, your skeleton is likely biased in a state of inhalation or exhalation. Being stuck in a given orientation of joint actions can restrict other ones, resulting in certain tissues and structures repetitively being stressed over time.