There are four types of Chinese martial arts that are increasingly categorized into increasing levels of difficulty to master: shuai jiao, chin-na, wai chuen and chigong.
Chin-na (“seize and break”; Cantonese: kahm nah) isn’t an individual style of Chinese martial arts. It’s a collection of kung fu techniques from many different martial arts that have developed over the centuries, and these skills can be applied while either standing or on the ground. A kung fu practitioner uses these techniques to grab and manipulate an opponent’s leg or arm in order to painfully control and lock his joints/muscles/tendons, rendering him incapacitated and unable to move. Chin-na teaches you about leverage, application of force, spatial orientation between you and an attacker, and how to read an opponent’s intentions and body weaknesses.