The basic methods used in physical assessment are inspection, palpation, percussion, and auscultation. Physical assessment begins with inspection. Simply stated, this is visual observation of the patient for physical signs. Because this skill appears simple, it is frequently omitted or done very superficially. Also, many persons find it difficult just to look at a patient without performing some concurrent motor function. Inspection should, however, be considered a pertinent part of the physical assessment of the patient. Most important in the use of inspection is the knowledge of the observer. In order to see, you must know what to look for and what you see must have meaning for you. A beginning nursing student might not recognize clubbing as a physical sign, while the knowledgeable person would recognize its meaning and use it in determining the direction for other aspects of the patient's physical assessment. Palpation uses the sense of touch to feel physical signs. In reality, palpation includes more than a tactile sensation. It includes temperature sense, vibratory sense, sense of position, consistency, motion, and form. Depending on the senses being evoked in the examination, different parts of the hands are used. For fine tactile discrimination, the tips of the fingers are used because they are the most sensitive. For temperature, the dorsa of the hands and fingers are used because the skin is thinner there than on the ventral surfaces. For vibratory sense, the palmar aspects of the metacarpophalangeal joints are used. And for position and consistency, the graspng action of the fingers is used. Again, palpation requires not only the knowledge of what you wish to feel, but skill in the technique of palpation so that you can actually discriminate and interpret what is b ing sensed. Percussion is a striking of the body surface to obtain sounds that vary in quality. The quality varies in relation to the density of underlying tissue. Sonorous percussion is used to determine the density of a specific tissue. For example, one hears a resonant sound over such low density tissue as lung, a dull sound over moderately dense tissue like the heart, and a flat sound, without resonance, over such high density tissue as the thigh. Definitive percussion, is used to distinguish between two structures with greatly differing densities. For example, definitive percussion can outline the heart against other thoracic structures.