There is an acupoint in the recess immediately behind the outer anklebone.
Normally used in combination with acupoint 6. Acupoint 5 is a hand's-breadth above the end of the inner anklebone, behind the shinbone.
This acupoint is very effective in lower-body problems, especially in combination with acupoint 5. It is a hand's-breadth below the bottom of the kneecap, on the outer side of the calf, in the cavity between the shinbone and the leg muscle.
In the middle of the sole of the foot, just behind the ball of the foot.