1. The Angle Between the Needle and the Skin
Perpendicular: In this method, the needle is inserted perpendicularly, forming a 90 degree angle with the skin. Most points on the body can be punctured in this way.
Oblique: The needle is inserted obliquely to form on angle of approximately 45 degree with the skin, suitable for the points where the muscle is thin or close to the important viscera. Points on the chest and back are often needled in this way.
Horizontal (also known as transverse insertion): The needle is inserted horizontally to form a 15-25 degree angle with the skin. This method is commonly used in the places where the muscle is thinnish.
2. Depth of Needle Insertion
A proper depth of needles induces better needling sensation without hurting the important tissue and organs clinically, the depth of insertion mostly depends on the shape of the patient, the location of the points and the pathological condition. For the elderly often suffering from deficiency of Qi and blood, or for infants with delicate constitution, and such places as the head, face, and back, superficial insertion is advisable. For the young and middle-aged with musculature or fatty shape, or for the points on the four extremities, buttocks, and abdomen, deep insertion is employed.