In today’s day and age ankle mobility is highly required but very much lacked. From dorsie flexion, plantar flexion, abduction, adduction, pronation and supination.
But the one that people and athletes struggle with the most is dorsie flexion. This movement requires great freedom and strength in the talocrural joint.
The joint is formed by the fibula, tibia and the talus. In the event of dorsie flexion ( like in a squat) these 3 bones work together to guide the movement. The talus is a very interesting bone, in the way that it is much wider in the front than in the back( looks like a trapezium). When the ankle dorsie flexes the fibula and the tibia form a mortise for the talus to move in. So taking into account all of the above. The ankle is in a open position when plantar flexed and in a closed position when in dorsie flexion.
The fibula in dorsie flexion rolls and slides superiorly. This is the point where you can make a difference in ankle mobility by not only mobilising the ankle but also treating the proximal tibiofibular joint, allowing the fibula to move superiorly giving the talus in the ankle more freedom in dorsie flexion.