Here the ankle (tarsal tunnel actually) forms the interface for the tibial nerve.  It is possible to produce openers and closers for nerve health in this location.  

LEFT: the large dark band is the neighbouring vein, the behaviour of which is a good indicator of the pressure in the area because it collapses and expands with small changes in pressure.  If the vein collapses, the area is under pressure.  Opening of the vein indicates a reduction in pressure. The nerve is immediately below the vein and note that it too becomes bigger when the pressure is reduced.