There are some reports that increased adductor muscle activity may be related to the display of knee valgus during certain movements, including bilateral squats (Padua et al. 2012) and unilateral squats (Mauntel et al. 2013). (strengthandconditioningresearch.com)
Healthy dorsiflexion improves quad activation and helps keep the knee from valgus collapse, or diving inward. (onnit.com)
Female athletes have wider hips, putting a higher valgus stress angle on their knees (knees inward), a stress that is the major factor of most non-contact ACL injuries. (sportstarsmag.com)