双刀 (Shuāng dāo)
Origin: China, developed as a dual-weapon system for battlefield agility. Created by Chen family masters.
Date: Introduced to Chen Taijiquan curriculum in later generations (likely 18th - 19th centuries).
Description: Two sabres used together, demanding ambidexterity, balance, and coordination. The form is dynamic, fast, and requires strong waist control, embodying Chen Taiji’s principle of whole-body harmony.