title: ACL update: objective measures on knee instability: an introduction.
authors.affiliation: University of Pittsburgh, UPMC Center for Sports Medicine, 3200 South Water Street, Pittsburgh, PA, 15203, USA. musahlv@upmc.edu.
authors.forename: Volker
authors.initials: V
authors.lastname: Musahl
authors.affiliation: Hospital for Special Surgery, 535 E. 70th, 6th floor, New York, NY, 10021, USA.
authors.forename: Anil
authors.initials: A
authors.lastname: Ranawat
keywords: ACL; Knee; Knee stability; Pivot shift