In ankle dorsiflexion, which direction does the talus move relative to the tibia?

In ankle dorsiflexion, which direction does the talus move relative to the tibia?

• A. Talus moves anteriorly on tibia
• B. Talus moves posteriorly on tibia
• C. Calcaneus moves medially relative to tibia
• D. Calcaneus moves laterally relative to tibia

Answer: (B)

In dorsiflexion at the ankle, the talocrural joint behaves with the talus as the convex surface moving on the concave tibia. During this motion, the talus rolls forward (anteriorly) but must glide in the opposite direction to stay within the mortise, which means it glides posteriorly relative to the tibia. So the talus moves posteriorly on the tibia in dorsiflexion. If you think about plantarflexion, the opposite glide occurs—the talus would glide anteriorly. The calcaneus is part of the subtalar joint, not the primary movement of dorsiflexion at the talocrural joint, so its medial or lateral movement relative to the tibia isn’t the defining direction here.

In dorsiflexion at the ankle, the talocrural joint behaves with the talus as the convex surface moving on the concave tibia. During this motion, the talus rolls forward (anteriorly) but must glide in the opposite direction to stay within the mortise, which means it glides posteriorly relative to the tibia. So the talus moves posteriorly on the tibia in dorsiflexion. If you think about plantarflexion, the opposite glide occurs—the talus would glide anteriorly. The calcaneus is part of the subtalar joint, not the primary movement of dorsiflexion at the talocrural joint, so its medial or lateral movement relative to the tibia isn’t the defining direction here.