Gu Ruzhang or Ku Yu-Cheung (Chinese: 顾汝章; pinyin: Gù Rǔzhāng; 1894–1952) was a Chinese martial artist who disseminated the Bak Siu Lum (Northern Shaolin) martial arts system across southern China in the early 20th century. Gu was known for his expertise in Iron Palm** hand conditioning among other Chinese martial art training exercises. He has become a legendary heroic figure in some Chinese martial arts communities.
Gu was a son of Gu Lizhi (顾利之), an adept of Tantui and Zhaquan and security and escort businessman (at the time, a common business for martial artists in China). Gu Yu-jeung inherited by his father's colleague Yán Jīwēn (嚴機溫)aka 嚴繼溫 the 10 North Shaolin routines, several weapon routines, and martial qigong techniques such as Iron Palm, Iron Body and Golden Bell. By such skills he was selected by the Central Guoshu Institute to teach Northern martial arts to the South as one of the "Five Southbound Tigers".
Gu also learned Zhaquan from Yú Zhènshēng (于振聲); Yang Taijiquan and Bajiquan from Li Jinglin (李景林); and Baguazhang, Xingyiquan from Sūn Lùtáng (孫祿堂).
Major events in Gu’s life are difficult to verify, as many of his achievements have been made legendary and may have been subject to gross exaggeration.
Gu was photographed breaking twelve un-spaced bricks with one strike. He entered the first National Wushu Fighting Examination and placed in the top 15 competitors. He was also an instructor for the Guangdong Armed Forces.
According to legend, Gu, in the same spirit as the folk hero Huo Yuanjia, defeated foreign fighters who viewed the Chinese martial arts as an inferior system of fighting.