Various forms of therapeutic superficial tissue manipulation have been practiced for thousands of years across cultures. Chinese use of massage dates to 1600 BC, and Hippocrates made reference to the importance of physicians being experienced with "rubbing" as early as 400 BC. There are references to massage in ancient records of the Chinese, Japanese, Arabic, Egyptian, Indian, Greek, and Roman nations. References to massage are also found in the Bible and the Vedas. Terms for massage include the French word masser , the Greek word for "knead," a Hindu word for "press," and an Aramaic word that means "to press softly." The technique that is currently called Swedish massage was developed in the 19th Century by Per Henrik Ling (1776-1839) as a combined form of massage and gymnastic exercises. Many different therapeutic techniques can be classified as massage therapy. Most involve the application of fixed or moving pressure or manipulation of the muscles/connective tissues of clients. Practitioners may use their hands or other areas such as forearms, elbows, or feet. Lubricants may be added to aid the smoothness of massage strokes. Techniques used in Swedish massage include (1) superficial stroking in a direction away from the heart or deep stroking towards the heart; (2) kneading in a circular pattern using fingers and thumbs; (3) deep muscle stimulation; (4) rhythmic movements such as slapping or tapping; and (5) vibration. Sports massage is similar to Swedish massage but is adapted specifically for athletes. Classical massage aims to provide calmness, relaxation, encourage self-healing, and revitalization. Many other variations and styles of massage or touch exist, often developed in specific geographic regions. Scientific research of massage is limited, and existing studies use a variety of techniques and trial designs. Firm evidence-based conclusions about the effectiveness of massage cannot be drawn at this time for any health condition.