Dynamic knee valgus, visually represented as medial knee displacement, is associated
with anterior cruciate ligament injury. Recently, restrictions in ankle dorsiflexion
range of motion have been associated with medial knee displacement. Therefore, interventions
potentially increasing ankle dorsiflexion range of motion could alleviate medial knee
displacement. The purpose of this pilot study was to explore the acute effects of
an intervention to increase ankle dorsiflexion range of motion and reduce medial knee
displacement in individuals who display medial knee displacement that is corrected
with a heel lift.
Eight young participants who displayed medial knee displacement corrected with a heel
lift completed a single-session intervention aimed at increasing dorsiflexion range
of motion. Immediately before and after the intervention session, dorsiflexion range
of motion in three static conditions (passive straight-knee, passive bent-knee, and
weight-bearing lunge) and medial knee displacement during an overhead squat were assessed.
The single-session training program increased participants’ dorsiflexion range of
motion in all three static conditions (p = 0.0005 for straight-knee, 0.02 for bent-knee, and 0.01 for lunge) with moderate
to large effect sizes (0.55–1.18). Additionally, the training resulted in a significant
reduction in medial knee displacement during the overhead squat (p = 0.02).
The finding indicate that our interventional protocol appears beneficial in increasing
dorsiflexion range of motion among individuals with medial knee displacement. Additionally,
improving dorsiflexion range of motion may be a promising direction for reducing medial
knee displacement, which is a risk factor for anterior cruciate ligament injury.