Tongbeiquan (通背拳 tōngbèiquán; literally “Spreading Power from the Back Boxing”) is a school of martial arts popular in northern China. Its precepts are Taoist in nature and many of the training methods are similar to those of internal styles. Traditional training includes basic training (stance, arm, leg, conditioning), combinations, forms , two-person free sparring, weapons, and qigong.
Originally, Tongbei may not have referred to a school of boxing but to a way of exercise. When the exercises are done, power is generated from the back to pass through the shoulders to reach the arms. In this way, heavy blows can be delivered at arm’s length to control the opponent.
Tongbeiquan emphasizes the combination of inner core and outward application.
(Wikipedia, https://en.wikipedia.org/wiki/Tongbeiquan)