This article is excerpted from the book Practical Qin Na Part 1: Explanation of the Qin Na Nine Heaven Secret Text by Zhao Da Yuan. A concise explanation of the concepts of Jin and Li in the internal martial arts. Although Master Zhao talks about Jin and Li in relationship to Qin Na, his discussion is relevant tall of the internal styles (Nei Jia).
The Five Elements (Metal, Fire, Water, Wood, and Earth). have implications for understanding the application of five kinds of Jin Li:
- Whole (Zheng 整) 
- Penetrating (Tou 透) 
- Round (Yuan 园)
- Alive/Lively (Huo 活) 
- Mysterious (Ling 灵)  or Skillful (Qiao 巧) 
These five qualities are the basis both for the application of Qin Na, and the ability to change and transform the Original Li (本力). Whether one is training basic skills or actually applying techniques, the five Jin Li must be employed. In combat, Qin Na techniques must be applied instantly at the first touch of the limbs. This first moment is a test of Jin Li (a trial of strength). Using Jin Li correctly in order to control the opponent, without yourself being controlled, is a key issue in Qin Na. A fundamental concern is to avoid awkward, one-dimensional Jin and instead employ unitary, clever, transforming Jin. Therefore, one must learn to transform Original Li into refined Jin Li through painstaking training.
Li (Force or Strength) generally refers to the force produced by muscular contraction. It is controlled by the nervous system and transmitted to the opponent via the bones. It is commonly referred to as Original Li (natural strength or power). Jin refers to force that is produced by the whole body, in combination with regulated breath and an organic internal contraction and expansion regulated by the Heart-Mind. Jin is able to change and transform harmoniously. Jin is deep, continuous, magnificent, and grand. Jin is round, tenacious, refined, and skillful. It shifts and transforms. Li is innate and instinctual. It transmits in a single direction and does not rotate easily. It is difficult to use Li flexibly. Jin is acquired and refined through training the body, Heart-Mind and Intention, so that they are unified and integral. Then Jin can quickly be expressed and transmitted and can effortlessly change and transform.
From another perspective, in traditional Chinese medicine and traditional martial arts, “Intention guides Qi and Qi urges Li.” In the Qin Na scriptures it says: Jin is expressed through Qi in the Dantian, expanding and contracting, coming and going, circulating continuously and endlessly like flowing water, manifesting in the eight directions (everywhere), accumulating and transforming, yielding and firm. Li is the foundation of Jin. Without Li there is no Jin. Jin is the integration of body and mind, and the refined use of Li. Collectively this is referred to as Jin Li.
The Five Kinds of Jin:
- Zheng Jin (整劲) is like the Earth, the center of the Five Elements, which gives birth to and develops all things. Zheng Jin comes from Original Li changing into Jin Li. It is the origin and root of transformation. Zheng Jin means that the forces distributed throughout the body consolidate and integrate into one, so that the techniques are in the hands, the foundation is in the feet, exhalation is in the abdomen, releasing Jin (Fa Jin) is in the abdomen, change and rotation are in the Yao, and Zheng Jin is integrated. Jing, Qi, Shen, and Li combine into one.
- Tou Jin (透劲) is like Metal. It can open up a mountain or penetrate through objects. Tou Jin is characterized by attacking and penetrating into a target. Emitting this Jin requires four corresponding sensations: 1) Having the intention of penetrating through.  2) The circulation of Qi has a sensation of penetrating through. 3) The eyes and vision have a sensation of penetrating through. 4) The Jin Li has a sensation of penetrating through. These four sensations are a result of the ability to concentrate the intention and will. You must be able to release the intention into the distance as though it passes through the target.
- Yuan Jin (园劲) moves and rotates, like wind stirred by Fire. The body and the movement of the internal Qi and Jin Li, float and rotate like a ball in accordance with the direction and amount of the opponent’s force. Then his force cannot concentrate against you. The techniques in Chinese martial arts and Qin Na are nothing more than the changes and transformations of Yin and Yang, and Qi and Zheng  generating each other. The transformations of Yin and Yang are like the Tai Ji diagram – their marvelous point of change and ultimately residing in “roundness.” The basic shape of motion is curved. Therefore roundness and circularity are the mother of martial arts. It is said that: opportunity is generated by the round, and marvelous subtlety is achieved by roundness.
- Huo Jin (活劲) is like Water. Its shape conforms to the terrain and it can adjust to move transform according to the circumstances. It leaves no gap, yet seeps into the smallest crack. In training Huo Jin, the application of Jin Li cannot be stiff. The Shen must be still and the Qi naturally unfolds. The body is loose and not blocked. Do not force the Qi or Li. The internal Qi should flow continuously and the internal Jin must move and transform in accordance with the situation. The body follows the changes, and the steps advance and retreat according to the circumstances. The hands are like a ring, smoothly going out and returning. Thus interior and exterior are integrated. Qi is like floating clouds, moving and shifting contiguously, while Jin Li changes unceasingly like flowing water. The body is like the axle of a cart, continuously moving and rotating. The hands revolve like rotating wheels. Step like a leopard, advancing and retreating, quickly and with agility. Above and below, inside and outside, are circular and lively, like the tides in a river, ceaselessly rising, falling, and flowing.
- Ling Jin (灵劲) is also referred to as Qiao Jing (巧劲). It refers to the methods and techniques of changing and transforming during application. This includes correct mechanics, skillful application of techniques and Jin, and knowing how to control the opponent without being controlled. Employing skill, rather than brute force, is fundamental to the art of Qin Na. One must carefully study the mechanics and structure of the body and the techniques in order to master the basic principles of body movement, force, angle, fulcrum, and lever. The object is to maximize the effect of Qin Na techniques while employing the minimum effort and force. This is called “Small Li defeats Big Li”, and “Using skill to overcome a 1,000 kilo weight.”
Entire, whole, full, ordered, or tidy.
 Penetrating or seeping through.
 Lively, active, vivid.
[4[ Clever, quick, sharp, efficacious, effective, mysterious.
Clever, intelligent, skillful, ingenious, opportune artful, deceptive.
 穿透 Chuan Tou
 奇正 Qi and Zheng: These terms reference Sun Zi and military strategy. Zheng refers to normal, orthodox or direct force (and tactics) and Qi, to the indirect, unorthodox, unusual or extraordinary forces and tactics.