Schmidt Daniel, Schlee Guenther, Germano Andresa M C, Milani Thomas L
Department of Human Locomotion, Faculty of Behavioral and Social Sciences, Institute of Human Movement Science and Health, Chemnitz University of Technology, Chemnitz, Germany.
Biophysics and Human Performance Lab, W.L. Gore and Associates, Putzbrunn, Germany.
PeerJ. 2020 Feb 3;8:e8479. doi: 10.7717/peerj.8479. eCollection 2020.
In research, assessing vibratory cutaneous sensitivity is an important research branch to quantify various diseases or to develop devices for pattern recognition. The measured vibration perception thresholds (VPTs), however, are subjective and usually result in a large data variability. This might induce difficulties to detect differences, for example, when comparing different anatomical locations. Hence, a higher ability to detect changes is desirable. Another feature of VPTs is spatial summation, but in the literature it is controversially discussed whether or not this phenomenon is also present in the lower frequency range. For these reasons, the present study aimed to investigate whether an enlarged matrix contactor area (measured at the hairy skin) induces improvements in subjective sensitivity using high and low frequencies, and whether a large contactor area is better able to identify changes of VPTs than a small contactor area of a single contactor. For each frequency, we hypothesized an increased sensitivity for the matrix compared to the single contactor. We also hypothesized that changes can be better-detected between the anatomical locations when using the matrix than the single contactor.
Twenty healthy and young participants voluntarily took part in this study. Three anatomical locations at the torso were measured at the middle aspect of the lower back, middle lateral aspect of the upper arm, and the region just below the armpit. At each location, two frequencies (30, 200 Hz) and two contactor conditions (single contactor: 0.48 cm , contactor matrix: 9 × 0.48 cm = 4.32 cm) were tested in a randomized order.
Supporting our hypothesis, we found that improved cutaneous sensitivity after increasing the contactor size occurs not only at high, but also at low frequencies at all anatomical locations. Large contactor sizes resulted in higher sensitivity and in a superior ability to detect changes. The superior behavior of the matrix to exhibit a lower variability could not always be proven. This work may be relevant for future studies aiming to identify changes of VPTs in various patient groups, for example.
在研究中，评估振动性皮肤敏感性是量化各种疾病或开发模式识别设备的一个重要研究分支。然而，所测量的振动感觉阈值（VPTs）是主观的，并且通常会导致数据的较大变异性。这可能会在检测差异时带来困难，例如在比较不同解剖位置时。因此，需要更高的检测变化的能力。VPTs的另一个特征是空间总和，但在文献中，对于这种现象在低频范围内是否也存在存在争议。出于这些原因，本研究旨在调查增大的矩阵接触器面积（在有毛皮肤上测量）是否会在高频和低频下提高主观敏感性，以及大接触器面积是否比单个接触器的小接触器面积更能识别VPTs的变化。对于每个频率，我们假设与单个接触器相比，矩阵的敏感性会增加。我们还假设，使用矩阵时比使用单个接触器能更好地检测解剖位置之间的变化。
20名健康的年轻参与者自愿参加了本研究。在躯干上的三个解剖位置进行测量，分别是下背部的中部、上臂的中外侧以及腋窝下方区域。在每个位置，以随机顺序测试两个频率（30、200赫兹）和两种接触器条件（单个接触器：0.48平方厘米，接触器矩阵：9×0.48平方厘米 = 4.32平方厘米）。
支持我们的假设，我们发现增大接触器尺寸后皮肤敏感性的提高不仅发生在高频，而且在所有解剖位置的低频下也会发生。大接触器尺寸导致更高的敏感性和更好的检测变化的能力。矩阵表现出较低变异性的优越行为并不总是能够得到证实。例如，这项工作可能与未来旨在识别各种患者群体中VPTs变化的研究相关。
