The Second empty hand form (Er Lu Changquan) also known as "Cannon Fist" of t'ai chi ch'uan/Taijiquan, (Chinese: 太极拳; pinyin: Tàijíquán), is a version of Tai chi composed of Forty-two movements, This Taolu it's a intermedium one to learn in Chen-Style Taijiquan.
When learning Laojia, the student first learns large, simple movements and gradually refines the form and internal alignment.
Chen Changxing (陈长兴 1771-1853) is credited with being the first to condense all the routines previously practised into two essential routines. Chen Fa Ke, the famous master who brought Chen Style to Beijing in the middle of the twentieth century, was a student of this “Old” and “Large” Frame. TheChen lao jia(old frame; 老架) consists of two forms yi lu (1st routine) and er lu (2nd routine) It was taught privately in Chen Village from the time of Chen ChangXing—the 14th generation creator of these routines.
Chen Changxing is also famous for teaching Yang Luchan (the founder of Yang Style tai chi). The traditional Yang style long routine is the result of his training with Chen Changxing.