NAVICULAR DROP TEST FOR SUBTALAR OVERPRONATION The Navicular Drop Test can be used to assess dynamic overpronation of the subtalar joint. Overpronation in turn is thought to cause a myriad of problems such as plantar fasciitis, knee valgus, patellofemoral pain syndrome and it can put the ACL at a greater risk. If you see a pronounced navicular drop, it is advised to strengthen the tibialis posterior muscle. At the same time there is more and more evidence emerging that challenges "overpronation"