Fujita T, Fujii Y, Okada S F, Miyauchi A, Takagi Y
Calcium Research Institute, Kishiwada, Osaka, Japan.
J Bone Miner Metab. 2001;19(3):175-9. doi: 10.1007/s007740170038.
Pain is a complex neurophysiological and psychological process associated with various electrodermal phenomena, including Galvanic skin response, a fall of resistance to Galvanic current. Because skin impedance, an alternative current counterpart of direct current resistance, is readily measured and is probably more sensitive and stable in reflecting the state of the skin, the relationship between changes in pain and skin impedance was evaluted in the present study. Baseline skin impedance was stable and reproducible within a short time of less than 1 h and on consecutive days with a coefficient of variation of 1%-4%, but it may vary more widely over a longer period of 1 year. Baseline skin impedance gradually rose with advancing age, and females tended to show higher values than males. A highly significant correlation was noted between the percentage fall in skin impedance in response to strain on the joint, such as standing, bending, squatting, walking on a flat floor, and ascending and descending stairs, and pain scores obtained by a visual rating scale according to the Spearman's rank correlation coefficient test. Measurement of the fall in skin impedance may be a useful index of pain-associated somatic changes for a better understanding of the overall manifestations of pain as a step toward to an objective evalution of pain.
疼痛是一个复杂的神经生理和心理过程，与各种皮肤电现象相关，包括皮肤电反应，即对直流电电阻的下降。由于皮肤阻抗（直流电电阻的交流电对应物）易于测量，并且在反映皮肤状态方面可能更敏感和稳定，因此在本研究中评估了疼痛变化与皮肤阻抗之间的关系。基线皮肤阻抗在不到1小时的短时间内以及连续几天内是稳定且可重复的，变异系数为1%-4%，但在长达1年的较长时间内可能变化更大。基线皮肤阻抗随年龄增长而逐渐升高，女性的值往往高于男性。根据Spearman等级相关系数检验，在诸如站立、弯曲、下蹲、在平坦地面行走以及上下楼梯等关节受力时皮肤阻抗下降的百分比与通过视觉评分量表获得的疼痛评分之间存在高度显著的相关性。测量皮肤阻抗下降可能是疼痛相关躯体变化的一个有用指标，有助于更好地理解疼痛的整体表现，作为朝着客观评估疼痛迈出的一步。
