One of the most commonly used points to support and tonify the kidneys is Kidney 3; KD3, Tai Xin, Great Canyon.
Located between the Achilles tendon and the ankle bone on the inner side of the foot.
It tonifies kidney yang, yin, Jing and qi. = massive support to the body. It can help with sleep, energy level, body temperature, water metabolism, back and knee pain, and hormonal imbalances.