A couple of techniques which Brian Mulligan developed are for regaining ankle dorsiflexion that is pulling your toes towards you, and plantarflexion or pushing them down or away. The first technique uses a movement of the tibia and fibula forwards while pushing the talus and navicular back. The patient is then asked to dorsiflex their ankle while overpressure is applied. It is interesting that the joint is moving in the opposite direction to which you would expect. This is because the joint actually glides as well as moving and getting the glide part right first, gives a much better result.
The second technique for plantarflexion is where the tibia and fibula are moved back and the talus and navicular are moved down while the patient is asked to point their toes and ankle down. Again this relies upon a pain free technique and a glide of the joints before the movement occurs.
These techniques can work very well in stiff ankles.