Mudra is a voluntary neuromuscular action (contraction) or posture with the help of which the prana is controlled and directed through a particular nadi, is known as mudra. That is why Viparita karani mudra is practiced as asana with a limited objective at the physical level. Mudra also means (1) Seal or the cast (mould) (2) Stamp, impression, (3) currency, (4) gesture, (5) a body position which gives joy and pleasure, (6) symbol, and (7) acting with some expression on the face.

Mudra is a symbolic or ritual gesture practiced from ancient times in Hinduism and Buddhism. Mudras involve the entire body and are performed with both hands and fingers. Mudra is considered to be the energetic "seal of authenticity" which is employed in the spiritual practice of Indian religions. Mudras involve the entire body and are performed with both hands and fingers. Reference of Mudra is found in the Eastern philosophies and it is the culture and Yogic practice. Mudra is also rightly defined as mystic hand gestures used to focus subtle energy through symbols.

Moreover, the bandhas are also included in mudras. Probably the reason is they are only four in number. Usually they are practiced as an essential part of pranayama. When they are practiced without pranayama, they are mudras. Therefore, mudras, which are practiced in pranayama are known as bandhas. They bind and direct the current of prana from a particular region and generate specific impulse. When these impulses are understood at the experiential level, the prana (vital energy or force) can be directed further through the specific route (nadi).

Gherand Samhita speaks about 25 mudras in 100 verses. Tantra mentions Ankush mudra, Abhaya mudra, Kumbha mudra, Vara mudra, and Shankha mudra. In Goroksha Shatak only six mudras are described.

The word mudra is not limited to yoga. They are also included in Tantra (e.g., Vijay Tantra, which saves a person from evil) and the art of Indian traditional dance as well as drama. Unlike in hatha yoga, in Tantra the importance is given to the special arrangements of the hands and fingers. While in Indian dance and drama, mudras are done with the help of eyes and face. The purpose is clearly of an expression or indication of the feelings. The term `mudra` is derived from two words like `mud` and `ra`. Here, `mud` means to rejoice or to be happy and `ra` means `to give`. Thus, Mudra is an action that provides delight or extreme joy. This is an indication that the practice of mudra is concerned with sensory aspect.

The concept of Mudras depends on the ten fingers of both hands in a human body. Each finger is associated with certain energy and meaning. The correct usage of the fingers gives the Mudra the potency to heal. The fingers are said to possess the five elements of as human body- fire, air, water, earth and sky that are present in fixed proportions and even the slightest imbalance of any of these can be disastrous. However, striking the balance among these elements is not easy. Thus practice of Mudra help to harmonise the five elements in the human body.

A detailed study of the fingers and their association with the five elements reveals that the thumb represents the element earth, the stomach and worry. The index finger constitutes the element metal and influences the lungs, the large intestine as well as control the emotions such as depression, sadness and grief. The middle finger is the element fire associated with the heart, small intestine, circulatory and respiratory systems, and the emotions are impatience and hastiness. The ring finger constitutes the element wood and is connected to the liver, gall bladder, and nervous system, and corresponds to anger. The little finger corresponds to water, the kidneys, and fear.

In addition to that, the fingers are also connected to profound meaning in astrology and palmistry. The little finger is Mercury and relates to communication. This finger is associated with the second chakra. The ring finger is associated to Apollo, the Sun God and refers to relationships and is the root chakra. The middle finger is the finger related to Saturn. It refers to responsibility and is associated with the throat chakra, the gateway of purity. Index finger is constituted with Jupiter. It refers to self-worth and is associated with the heart chakra. Finally the thumb is connected to Mars. It refers to self-assertion and is associated with the fire element.

Origin of Mudras is quite ancient. According to mythology, Lord Shiva is considered to have initiated the basic Mudras. The practice of Mudra is prevalent in all over the world. It is found in every form and is used in religion, dance, art, and even in Tantra. The significance of Mudra is both exoteric and esoteric. Mudra is also a useful identification of the Buddha, Bodhisattvas and deities.

Mudra Vigyan or the science of finger postures occupies a prominent position among the ancient Indian Sciences. The science of Mudra is quite interesting. In order to harmonise the undercurrents of the mind, science of Mudra is considered significant. Furthermore, Mudra Vigyan is the aspect that helps in practicing meditation. Mudras have always been treated as an esoteric science. Thus it can be said that Mudra Vigyan is a distinct and independent branch of yoga. In addition to that Mudra Vigyan denotes the five fingers which are the representation of five tattvas.

The main purpose of Mudra is to uplift the human soul and promote the individual to achieve divine powers. Moreover, Mudras can keep the body perfectly fit. However, besides providing spiritual gains, the Mudras are valuable for its therapeutic use also. Constant researches have brought forth a wide range of Benefits of Mudras.

Mudras can be described as psychic, emotional, devotional and aesthetic gestures or attitudes. Varied types of Mudras are introduced for different uses. Yogis have considered Mudras as attitudes of energy flow and linked them to individual pranic force with universal or cosmic force.

According to Hathapradipika and Shiv Samhita there are ten types of mudras namely (l) Mahamudra (2) Mahabandha(3) Mahauedha (4)Khechari (5)Uddiyan (6) Mula bandha (7) Jalandhara bandha (8)Viperita karani (9) Vajroli and (10) Shaktichalana. Vajroli is further subdivided into Sahajoli and Amroli.

According to Hathapradipika, mudras are practiced for awakening of the Kundalini power (Kundalini Prabodhana) while Gherand Samhita recommends it for equilibrium and stability (Sthirata). Mudras are practiced to stimulate a particular neuromuscular area (e.g., anal sphincters as in Ashwini mudra) of the body by voluntary muscular contraction maintained for some length of time or repeated with counter relaxation. This generates currents of energy that travel upward. They minimize the activity of mind and the sadhaka experiences the mental and emotional stability.

Mudras are a combination of subtle physical movements which alter mood, attitude and perception, and deepen awareness and concentration. The term Mudras of universal application is apt. Mudras especially bring about miraculous changes and improvement in human body. In addition to that Mudras generate power to provide peace and happiness.

Benefits of Mudras are many as this science of gesture is used in innumerable way. Mudra can help in balancing the flow of energy through the `nadis` that nourish the internal organs of human body. Mudras in therapeutic use have also gained prominence. A regular practice of Mudras can cure insomnia, arthritis and memory loss. They can also be performed to achieve specific states of consciousness. In addition to that mastering this art of gesture can help eliminate negative thoughts and aid mood elevation. Furthermore, Mudras can be used in meditation too. Mudra and Meditation can bring a change in the human mind. Mudras and colour forms a unique combination and stimulates positive energy in the body, mind and soul of a human being.

Mudras can be practiced either before or after other yoga practices such as pranayama or asanas. Mudras are one of seven practices that yogis employ to listen to the inner sounds. A wide range of Mudras can be practiced without any difficulty; especially to aid visualisation of the sushumna. Many Mudras are normally associated only with the hands and are used in Indian dancing like the Chit-mudra that denotes chit or wisdom of the highest consciousness.