Anatomy of the Cun Position at Wrist and Its Application in Pulse Diagnosis

Information on anatomy of the Cun position at wrist is lacking; whether the blood vessel taking pulse in Cun is the radial artery or the superficial palmar branch is also clinically controversial. The objective was to investigate the boundaries and contents, and the vascular distribution and their pulse points in Cun. Thirty-two upper extremities of 16 human cadavers were investigated for dissection and observation. The boundaries, contents, and blood vessel distribution in Cun were observed; the location of pulse points in Cun was identified; the length of the superficial palmar branch in wrist pulse (L1), the pulp width of the index finger (L2), and the angle between the radial artery and the superficial palmar branch were measured. The results showed that the Cun was located in the region formed by the bulge of the prominent bone proximal to the palm, the radial flexor tendon, the tubercle of scaphoid, and the abductor longus muscle tendon. In this area, the radial artery could be pulsed part in the medial side of the abductor longus muscle tendon, while the superficial palmar branch lied near the surface and was easy to pulse in the lateral side of the radial flexor tendon and the medial side of the tubercle of scaphoid. The ratio of L1 to L2 was 1.2±0.8, and the angle was 23.3±9.9°. The results suggested that it could not be generalized that the blood vessel taking pulse in Cun was the radial artery or the superficial palmar branch; it might depend on the vascular distribution in Cun, the region of finger positioning, and the patient's pulse condition.