TCM acupuncture is the practice of penetrating the skin with thin, solid, metallic needles which are then activated through gentle and specific movements of the practitioner's hands or with electrical stimulation. Acupuncture is part of the ancient practice of Traditional Chinese medicine. TCM originated in ancient China and has a history of over two thousand years. Influenced by ancient Chinese philosophy, culture, and science and technology, Chinese medicine uses the theory of Yin and Yang and the theory of Wu Xing (5 phases) to explain the mechanism of balancing the function of the body. The Five Phases are Fire , Water , Wood, Metal, and Earth. Western medical acupuncture (also known as dry needling) is a therapeutic modality involving the insertion of fine needles; using current knowledge of anatomy, physiology and pathology, and the principles of evidence-based medicine. It is mainly used to treat musculoskeletal pain, including myofascial trigger point pain. Western medical acupuncture is principally used by conventional healthcare practitioners, most commonly in primary care. It is also effective for postoperative pain and nausea. Practitioners of Western medical acupuncture tend to choose classical points as the best places to stimulate the nervous system.