The exact location of the Polar Spring point is at the apex of the armpit. The efficacy of this point is mainly for treating heart diseases and pain in the upper limbs, neck and shoulders. It is the starting point of the Heart Meridian of the Shao-Yin Heart and is located at the apex of the armpit, where the pulsation of the axillary artery can be felt. When sitting in the upright position, stretch one hand flat, raise the palm upward, bend the elbow, palm facing one’s head, and use the tip of the middle finger of the other hand to press the opposite side of the armpit in the middle of the depression, and there is a feeling of pain when pressing, that is, the point of Extreme Spring is located. Generally, when the needle is pricked to the extreme spring point, there will be a kind of electric numbness transmitted to the fingers. The brachial plexus nerve passes underneath this point. Pressing and kneading this point can relieve pain in the upper limbs and improve the function of the upper limbs. This point belongs to the Heart Meridian of the Shao-Yin Heart, and can be used to treat many heart diseases, such as heart pain, palpitations (accelerated heartbeat, often accompanied by panic), panic, and constipation. Selection of acupoints for treatment is not recommended for self-massage of acupoints, but should be carried out by a professional Chinese medicine practitioner for diagnosis and treatment.