Needle at Sea Bottom is not just the name of a 
posture in the Yang Form. It isan example of how myth and fact have blended throughout China’s long history to become accepted as history.
Han Hoong Wang – Needle at the Sea Bottom
Sun Wukong, also known as the Monkey King, is a mythological figure who features as a main character in the 16th century Chinese classical novel Journey to the West.
Sun Wukong establishes himself as a powerful and influential demon. In search of a weapon, he travels to the oceans and visits Ao Kuang, the Dragon-King of the Eastern Seas.
The Dragon King had heard rumours of this magical monkey. Word had it he had many tricks up his sleeve. Not wanting any trouble, the Dragon King ordered his subjects to bring out a few weapons for Monkey to try. 
“These are all like toothpicks. Don’t you have anything heavier?” he asked.
The Dragon King was desperate, when his wife swam up and suggested a giant iron pillar sitting in their treasury. She said the pillar lit with a heavenly glow days before, and maybe the monkey was fated to own it. The Dragon King agreed, and took the monkey to see this treasure.
The giant pillar was sitting in the furthest courtyard of the palace. Engraved on its side were the words, “The Compliant Golden-Banded Staff.” It was wide as a barrel, 20 feet tall and weighed 13,500 jin (8.1 tons). This pillar was also, mostly symbolically, responsible for keeping the sea stable.
The Monkey King’s eyes brightened when he saw it. He tried lifting it—and while he could pick it up, it was too cumbersome to wield. “Hmm… it’s too big to hold, I wish it could be smaller…”
Before he finished this thought, the pole suddenly shrank to the size of a shepherd’s staff, and flew into his hand. The Monkey King was ecstatic. He began whirling and twirling it, causing huge currents in the palace. The Dragon King and his courtesans were nearly swept away!
Happy with having found the perfect weapon, Monkey magically shrunk the rod again—this time to the size of a needle. He tucked it behind his ear, where he could carry it for future use in battle. He quickly thanked the Dragon King and set off for home.
Below is an example of an application for the technique.
https://taijiyang.wordpress.com/2008/09/10/needle-at-sea-bottom/ http://www.shenyunperformingarts.org/learn/article/read/item/m4e3jKphVCo/golden-cudgel-monkey-king-weapon.html
https://en.wikipedia.org/wiki/Sun_Wukong