🌿 Folk Prescriptions

The angle, direction, and depth of acupuncture refer to the specific operational requirements after inserting the fine needle beneath the skin. Mastering correct needle angle, direction, and depth is crucial for achieving proper sensation (de qi), applying tonifying and reducing techniques, enhancing therapeutic effects, improving acupuncture efficacy, and preventing complications. Correct acupoint selection must combine not just surface location but also appropriate angle, direction, and depth to fully activate the therapeutic function of the acupoint. Therefore, acupoints should not be viewed merely as flat points but as three-dimensional structures. Even the same acupoint can yield different outcomes in terms of tissue stimulation, sensation, and therapeutic effect depending on variations in angle, direction, and depth. For clinicians, proficiency in acupuncture technique is directly related to their ability to properly control these parameters. The actual angle, direction, and depth used depend on the site, treatment needs, and patient’s physical condition.
1. Needle Angle: Refers to the angle between the needle shaft and the skin surface. The angle varies based on acupoint location, disease nature, and technique requirements. Generally classified into three types: vertical, oblique, and horizontal.
1. Vertical Insertion: The needle forms a 90° angle with the skin, inserted vertically into the acupoint. Suitable for most acupoints, especially those in thick muscle areas.
2. Oblique Insertion: The needle forms approximately a 45° angle with the skin, inserted at an incline. Used for shallow skin areas, regions with vital organs, or acupoints unsuitable for deep vertical insertion, particularly in joints. Also commonly used during certain Qi-regulating or Qi-moving manipulations.
3. Horizontal Insertion (also called transverse or subcutaneous insertion): The needle forms about a 15° angle with the skin, inserted horizontally. Ideal for acupoints in thin skin and minimal flesh, such as on the scalp, face, and sternum. Techniques like trans-acupoint needling, scalp acupuncture, and wrist-ankle acupuncture also use horizontal insertion.
2. Needle Direction: Refers to the orientation of the needle tip during insertion and after entry—the so-called "needle direction." Direction is determined by the meridian pathway, acupoint distribution, and target tissue structure. While related to angle—for instance, facial acupoints often use horizontal insertion, neck and throat points use transverse insertion, midline chest points use horizontal insertion, lateral chest points use oblique insertion, abdominal points use vertical insertion, back and waist points use oblique or vertical insertion, and limb points usually use vertical insertion—angle primarily depends on anatomical features, whereas direction is tailored to specific therapeutic needs. For example, regarding the Jia Che point: when treating jaw disorders, cheek pain, or locked jaw, insert the needle obliquely toward the temporal region to radiate sensation across the entire cheek; for facial paralysis or mouth deviation, insert horizontally toward the corner of the mouth; for mumps, insert obliquely toward the parotid gland; but for toothache, use vertical insertion.
3. Needle Depth: Refers to how deeply the needle penetrates the skin and flesh at the acupoint. Proper depth should achieve de qi sensation without injuring internal organs or tissues. Clinical depth must consider multiple factors including patient age, constitution, condition, acupoint location, depth of meridian pathways, seasonal timing, practitioner experience, and need for de qi. As stated in *Suwen·Ciyao Lun*: “Needling has depth and shallowness, each according to its principle… improper depth becomes a great harm,” emphasizing that depth must be appropriate. To correctly determine depth, pay attention to the following:
1. Age: According to *Ling Shu·Nishun Feishou*, “For infants and thin individuals, insert shallow and quickly; for robust adults and obese individuals, insert deep and retain.” Elderly and weak individuals have declining qi and blood; children have tender constitutions (yin and yang immature); thus, deep insertion is not recommended. Young adults, with abundant qi and blood, may tolerate deeper insertion.
2. Body Build: Patients vary in physique—fat or thin, strong or weak. *Suwen·Sanbu Jiugou Lun* states: “First assess the body shape—fat or thin—to regulate qi deficiency or excess.” Zhang Zhicong adds: “Knowing body build determines needle depth.” Thus, thinner, weaker individuals should receive shallower insertion; fatter, stronger individuals may tolerate deeper insertion.
3. Location: Insert shallowly for acupoints on the head, face, and back; deeper insertion is acceptable for limbs and buttock-abdominal acupoints.
4. Meridians: Meridians vary in depth and yin-yang attributes. Ancient texts suggest deeper insertion for main channels (deeper), shallower for collateral channels (shallower); yang channels (surface) should be shallow, yin channels (interior) deeper. As *Ling Shu·Yinyang Qingzhuo* says: “For yin channels, insert deep and retain; for yang channels, insert shallow and quickly.” Generally, meridians running through elbows, arms, knees, and legs are deeper, requiring deeper insertion; those on wrists, ankles, fingers, and toes are shallower, requiring shallower insertion.
5. Condition: *Ling Shu·Weiqi Shichang* notes: “Diseases vary in depth and shallowness—cannot be fully enumerated—each resides in its own place. Mild cases: shallow insertion; severe cases: deep insertion; mild: small dose; severe: larger dose—adjust according to changes.” *Ling Shu·Zhongshi* also says: “For full pulse, deep insertion to release qi; for empty pulse, shallow insertion to prevent loss of essence and nourish the channel, expelling pathogenic factors alone.” This shows depth must be adjusted based on syndrome differentiation.
6. Technique: *Yixue Rumen* states: “Tonification draws qi from Wei (defensive), so light and shallow insertion is used, following Wei qi afterward to replenish deficiency; drainage removes Qi from Ying (nutritive), so heavy and deep insertion is used, meeting Ying qi ahead to drain excess.” *Nanjing* says: “Puncture Ying without harming Wei, puncture Wei without harming Ying”—emphasizing that depth in technique must be precise and purposeful. If deep insertion is required but shallow is used, the Ying layer is missed while Wei is harmed; if shallow is needed but deep is used, excessive damage occurs to Ying.
7. Seasonal Timing: Human body and seasons are closely linked. Acupuncture must adapt to seasonal changes. *Suwen·Zhenyao Jingzhong Lun* says: “Spring, summer, autumn, winter each have their respective rules.” Depth must consider both condition and season. *Ling Shu·Ben Shu* says: “In spring, treat collateral vessels, major channels, and intermuscular spaces—deep for severe cases, shallow for mild ones; in summer, treat all transport points, capillaries, muscles, and skin; in autumn, treat all convergence points, follow spring methods; in winter, treat all well points and transport points—deep and retained.” Generally, shallow insertion in spring and summer, deep insertion in autumn and winter—this rule stems from *Nanjing*: “In spring and summer, yang energy rises to the surface, human qi also ascends, so shallow insertion is appropriate; in autumn and winter, yang energy descends, human qi also sinks, so deep insertion is suitable.” Failure to follow seasonal patterns risks causing “great disorder” as warned in *Suwen·Sishi Ci Nizhong Lun*: “All four-season acupuncture must follow natural order. Deviation leads to chaotic qi and illness.”
8. De Qi Sensation: For patients with strong, fast, intense sensations (aching, numbness, heaviness, distension) or high anxiety about needles, shallow insertion is preferable. For those with delayed or weak sensations, deeper insertion is better. As *Zhenjiu Dacheng* states: “The depth of needling should stop when startled by the needle”—meaning depth should be guided by de qi sensation. Angle, direction, and depth are inseparable. Generally, deep insertion uses vertical insertion; shallow insertion uses oblique or horizontal insertion. For acupoints near the medulla, eyes, chest, abdomen, and back, where vital organs exist, careful attention to angle, direction, and depth is essential to avoid complications.