Standard reference value for tactile localization acuity in upper limb among the typically developing adolescents

Tactile localization refers to the ability to detect the sensory contact point. Tactile localization is one of the standard tests that can be done as part of a combined cortical sensory evaluation. Till date there is no normal reference available for estimating tactile localization. To calculate the normative reference of TL among school going children aged between 13 to 17 years. one forty healthy school going children aged between 13 to 17 years were included in this cross sectional study. The sample was recruited by stratified random sampling method from Panipat, Ambala (Haryana). Anthropometric measurements were taken by using calibrated weighing machine and stadiometer. After that tactile localization acuity established by PPTL technique. In this technique the children were asked to relocate the point of contact made by investigator by using black or red marker pen over identified 12 areas. These 12 areas are Upper lateral arm (ULA), Lower lateral arm (LLA), Middle posterior arm (MPA), Mid medial arm (MMA), Mid medial forearm (MMF), Mid lateral forearm (MLF), Mid posterior forearm (MPF), Distal thumb (DT), Palmar little finger(PLF), Palmar distal long finger (PDL), First dorsal interosseous (FDI),Dorsal proximal long finger (DPL). After that the distance between the points made by investigator and children were measured by measuring tape in centimeters. Age, weight, height, BMI of the children recruited were 14.2 (14.0 to 14.5)years, 46.5 (45.4 to 49.8)kg ,158.3 (157.1 to 159.9)cm, 18.4(18.1 to 19.4)kg/m2 respectively. Reference norms for tactile localization acuity(cm) in ULA=1.8 (1.6 to 2.0); LLA= 1.8 (1.6 to 2); MPA= 1.8(1.6 to 2); MMA= 2.0 (1.8 to 2.2); MMF= 2.2 (2.0 to 2.5); MLF= 2.1 (1.9 to 2.4); MPF= 2.0 (1.8 to 2.3); DT=0.6 (0.5 to 0.7); PDL=0.5 (0.4 to 0.5); PLF= 0.5 (0.4 to 0.5); FDI=0.7 (0.6 to 0.8); DPL=0.8 (0.7 to 1.0)
Conclusion- Normative reference score among children aged between 13 to 17 years have been established.

触觉定位（Tactile localization）指感知触觉接触点的能力。触觉定位是联合皮层感觉评估中的标准检测项目之一。迄今为止，尚无用于评估触觉定位的正常参考标准。
为明确13至17岁学龄儿童的触觉定位正常参考值，本横断面研究共纳入140名13至17岁的健康学龄儿童。研究对象通过分层随机抽样法从哈里亚纳邦的帕尼帕特、安巴拉地区招募。采用校准后的体重秤及身高计完成人体测量学指标采集。随后采用PPTL技术评估触觉定位敏锐度：要求受试者使用黑色或红色记号笔，在预先标记的12个区域内重现研究者此前施加触觉刺激的接触点。该12个区域分别为：上臂外侧（Upper lateral arm, ULA）、下臂外侧（Lower lateral arm, LLA）、臂后中段（Middle posterior arm, MPA）、臂内侧中段（Mid medial arm, MMA）、前臂内侧中段（Mid medial forearm, MMF）、前臂外侧中段（Mid lateral forearm, MLF）、前臂后中段（Mid posterior forearm, MPF）、拇指远端（Distal thumb, DT）、小指掌侧（Palmar little finger, PLF）、长指掌侧远端（Palmar distal long finger, PDL）、第一骨间背侧肌（First dorsal interosseous, FDI）、长指背侧近端（Dorsal proximal long finger, DPL）。随后使用卷尺以厘米为单位，测量研究者标记的刺激点与受试者重现的接触点之间的距离。
纳入受试者的年龄、体重、身高及体质量指数（Body Mass Index, BMI）分别为14.2（14.0~14.5）岁、46.5（45.4~49.8）kg、158.3（157.1~159.9）cm及18.4（18.1~19.4）kg/m²。各区域触觉定位敏锐度（单位：cm）的参考正常值如下：上臂外侧（ULA）：1.8（1.6~2.0）；下臂外侧（LLA）：1.8（1.6~2.0）；臂后中段（MPA）：1.8（1.6~2.0）；臂内侧中段（MMA）：2.0（1.8~2.2）；前臂内侧中段（MMF）：2.2（2.0~2.5）；前臂外侧中段（MLF）：2.1（1.9~2.4）；前臂后中段（MPF）：2.0（1.8~2.3）；拇指远端（DT）：0.6（0.5~0.7）；长指掌侧远端（PDL）：0.5（0.4~0.5）；小指掌侧（PLF）：0.5（0.4~0.5）；第一骨间背侧肌（FDI）：0.7（0.6~0.8）；长指背侧近端（DPL）：0.8（0.7~1.0）。
结论：本研究明确了13至17岁学龄儿童的触觉定位正常参考值。