Change of Safe Needling Depth at Acupoint GB21 according to Posture and Breathing

<div>Ultrasound image of GB21. Ultrasound image, sagittal view of GB21. The trapezius muscle is seen beneath the subcutaneous fat. Underneath it is the levator scapulae muscle. The 1st and 2nd ribs lie below the levator scapulae muscle, and the pleural membrane and lung are below the ribs.</div>

Evidence-Based Complementary and Alternative Medicine

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Figure 2

Figure 2: Change of Safe Needling Depth at Acupoint GB21 according to Posture and Breathing 