Decreased dorsiflexion during landing tasks are associated with kinetics and kinematics that increase the risk of ACL injury according to a 2015 study (Malloy, 2015.) The study was conducted on 23 female collegiate soccer players. The study utilized a 3D motion capture system analyzing kinetic and kinematic data during a drop vertical jump. This data was then correlated to dorsiflexion flexibility measured using traditional goniometry in a knee extended position. It was found that significant negative correlations exists between dorsiflexion flexibility and peak knee abduction moments and knee flexion. This means that an ankle with more dorsiflexion range will experience greater knee flexion range of motion during landing and less knee abduction moment, which is the moment which would accelerate knee valgus. We know that landing mechanics that utilize a stiff leg strategy as well as those that increase knee abduction moments are correlated with elevated injury risk to the ACL. This study corroborates with previous studies showing similar findings. This information furthers the importance of acquiring dorsiflexion mobility in at-risk populations for ACL injuries especially those rehabbing from ACL rupture.
Malloy P, Morgan A, Meinerz C, Geiser C, Kipp K. The association of dorsiflexion flexibility on knee kinematics and kinetics during a drop vertical jump in healthy female athletes. Knee Surg Sports Traumatol Arthrosc. 2015;23(12):3550-5.