Illustration from a Japanese handbook of moxa and acupuncture, showing acupuncture of the hand. The needle rests in the finger while a hammer is used to tap the knuckle - a way of heightening the effect of the acupuncture. Taken from Masatorio Hongo's 'Shin kiu choho jikki komoku' published in Osaka in 1718. In traditional Chinese medicine illness is attributed to an imbalance of vital energy or Ch'i, which flows through the body along twelve pathways (meridians) each of which corresponds to one of the vital organs. The imbalance is corrected by inserting needles at specific points on the meridians to stimulate the energy flow.