Bā Guà Zhǎng (八卦掌), often translated as "Eight Trigram Palm" (but more aptly termed "Eight Sectional Palm") is one of the 3 "Internal Styles" (內家功夫 Nèi Jiā Gōngfú) identified by Sūn Lùtáng (孫祿堂, 1861-1932), the other two being Xíng Yì Quán (形意拳) and Tài Jí Quán (太極拳).
"Internal" means that power is developed not though one's muscles, but through proper technique and body structure. The term "internal" is often used interchangeably with "soft" because forces are redirected instead of being met with equal or opposite force. But make no mistake; soft does not equal weak.
The trademark of Bā Guà is the "circle" (or more accurately, the "octagon"), a training tool and strategy used to develop the dexterity, balance and fluidity needed to apply Bā Guà techniques in combat.
Like other internal styles, proper Bā Guà practice does not damage the body the way western boxing, Muay Thai, and Tae Kwon Do often do, and can therefore be practiced for a life time. For young and old practitioners alike, it can offer a host of health benefits such as increased strength, flexibility, endurance, V02 max, awareness of ones surroundings, and overall body control.