Painealgometria

Painealgometria, or pain algometry, is a quantitative method for assessing pain sensitivity and tolerance by applying controlled noxious stimuli to a body site and recording responses. It is used in clinical and research contexts to evaluate somatic pain processing and the efficacy of analgesic interventions.

The most common modality is pressure algometry, using a hand-held algometer (a pressure sensor with a translating probe) that increases pressure at a constant rate until the subject indicates pain. Output measures include the pressure pain threshold (PPT) and, less commonly, pain tolerance. Other modalities include thermal algometry (heat or cold) and electrical algometry. Results are typically reported as the minimal stimulus intensity that elicits pain, expressed in units such as kilopascals (kPa) or newtons (N) depending on the device.

Standard procedure involves calibration of the device, defined rate of pressure increase, selected anatomical sites, and standardized instructions. Common sites include muscular areas such as the trapezius, extensor forearm, and quadriceps. Tests are typically repeated and averaged, with attention to factors such as age, sex, and psychological state, which can influence results.

Applications include monitoring pain in patients, assessing analgesic responses, and studying mechanisms of pain amplification like hyperalgesia and central sensitization. In research, algometry provides objective correlates to subjective pain reports, but results are influenced by subjective reporting, operator technique, device precision, and protocol differences; thus it is usually supplementary to clinical assessment rather than a standalone diagnostic tool.

See also: Algometry; Pain threshold; Pain tolerance.