"Empty Armpits"...

 Anyone familiar with the fundamentals of Taijiquan theory has probably encountered the phrase, “sink the shoulders, drop the elbows” (沉肩坠肘).  This principle emphasises relaxation and sinking—first by relaxing the shoulders allowing them to sink, and then letting the elbows naturally drop.  

To achieve “dropping of the elbows,” there’s another essential concept - “empty armpits” (空腋).  This term literally means “keeping the armpits empty”.

From the perspective of the elbows, two key elements are involved: firstly, that “the elbows do not leave the ribs” and secondly, that “the elbows do not press against the ribs”.   Balancing these two principles—keeping the elbows close to the ribs without pressing against them—is critical.

In China the analogy used is to imagine holding a soft and springy steamed bun under each armpit while practising. To maintain the bun in a state of “almost holding, yet not holding,” one must apply just the right amount of pressure. Squeezing too tightly will flatten it and not holding enough will cause it to drop. This practice protects the ribs with the elbows while preserving arm flexibility. Over time and with consistent effort, the habit of “empty armpits” develops, facilitating the proper execution of “sinking the shoulders, dropping the elbows”

Most traditional martial arts emphasise similar ideas. The reasoning lies in two key aspects of combat: defensive protection and enhanced power generation. When the arms are raised too high and the elbows are too far from the ribs, the rib area becomes exposed and vulnerable. Maintaining proper alignment also allows power to be transmitted more effectively and with greater penetration.

Although many people practise Taijiquan nowadays primarily for health, cultivating the habit of “empty armpits” through persistent practice can be beneficial.  From a Traditional Chinese Medicine perspective, this practice  “opens” the “Jiquan point” (an acupoint under the armpit), enhancing the circulation of qi and blood through the upper limbs. This is beneficial for the Heart Meridian of Hand Shaoyin and its normal function.