We can translate Xuanzhong by 'hanging bell'
It's the point hui of the marrows. It will tone the marrow and strengthen the bones.
Location of Xuanzhong
Xuanzhong is located 3 Cun above the top of the external malleolus, at the anterior edge of the fibula.
Move the bone up until it disappears under the muscle.

Livre - Méridiens et points d'acupuncture
Ouvrage illustré : 183 points
Therapeutic functions and clinical indications of Xuanzhong
In chinese medicine, it is said that “The brain is the sea of marrow”.
- Xuanzhong treats mental fatigue, memory loss, difficulty concentrating and intellectual gaps;
- It is used in cases of bone deformation or degeneration.
Xuanzhong will nourish the blood “The marrows produce the blood”.
- It is used to treat tendino-muscular pathologies of the lower limb.