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- Issue 32
- Rearfoot strikes more frequently apply combined…
Rearfoot strikes more frequently apply combined knee valgus and tibial internal rotation moments than forefoot strikes in females during the early phase of cutting maneuvers
- Ground reaction forces acting anterior or posterior to the tibial axis rotate the tibia oppositely.
BACKGROUND & OBJECTIVE
The ground reaction force (GRF) acting on the stance limb during non-contact deceleration creates an external force capable of tearing the anterior cruciate ligament (ACL). Anterior tibial translation, valgus (VL) and internal rotation (IR) moments contribute to this possibility.
If the rearfoot hits the ground first, the center of pressure (CoP) is posterior to the ankle with the moment arm (MA) extending posteriorly and should create valgus and internal rotation. With a forefoot strike, the CoP is anterior to the ankle, the MA is directed anteriorly, and the tibia should externally rotate (ER) and undergo varus. The purpose of this study was to validate if these foot striking patterns occur.
Hamstring muscle activation is one factor that restrains the internal rotation of the tibia and reduces strain on the ACL.
24 females with 5 years of well-trained cutting experience performed a planned cutting maneuver, at slow speed, where they utilized their preferred limb to plant and change direction toward the opposite side of the stance leg at 60°, under rearfoot