“…During the same period, approximately 5-6% will sustain a contralateral ACL rupture (Ahlden et al, 2012;Crawford, Waterman, & Lubowitz, 2013;Hettrich, Dunn, Reinke, Group, & Spindler, 2013;Lind, Menhert, & Pedersen, 2012;Salmon, Russell, Musgrove, Pinczewski, & Refshauge, 2005;Shelbourne, Gray, & Haro, 2009;Spindler et al, 2013). Young age (Ahlden et al, 2012;Faltstrom, Hagglund, Magnusson, Forssblad, & Kvist, 2014;Hettrich et al, 2013;Kvist, Kartus, Karlsson, & Forssblad, 2014;Lind et al, 2012;Magnussen et al, 2012;Maletis, Inacio, & Funahashi, 2013;Shelbourne et al, 2009;Wasserstein et al, 2013;Webster, Feller, Leigh, & Richmond, 2014) and returning to high activity level after an ACL injury (Borchers, Pedroza, & Kaeding, 2009;Faltstrom, Hagglund, & Kvist, 2013;Salmon et al, 2005;Shelbourne et al, 2009;Sward et al, 2010) have been highlighted as the most important risk factors for sustaining a contralateral ACL injury or an ACL graft rupture. Age may be a proxy for neuromuscular maturation, and altered neuromuscular control of the knee and hip and impaired postural stability has been reported to predict a second ACL injury (Paterno et al, 2010).…”