Reliability analysis of static and dynamic plantar pressure measurements of children and youths with normal development

ABSTRACT Plantar pressure is used in clinical evaluation of the feet and informs about characteristics of the plantar load distribution during functional activity. Many evaluation instruments are used and its measurements properties must be tested. Test-retest reliability is a measure which informs about reproducibility. The objective of this study was to analyze test-retest reliability of maximum pressure measurements during static and dynamic in children and youths with normal development (ND). Eleven children and youths with ND of both sexes, with mean age between 6 and 17 years old, were evaluated twice in a weight bearing platform in orthostatic posture, barefooted and with their usual footwear, when the feet were positioned spontaneously (interrupted step) and the feet were aligned. Intraclass correlation coefficients (ICC) were analyzed (α=0.05). ICC were consistent for: anterior barefoot weight bearing (ICC=0.83) and posterior barefoot weight bearing (ICC=0.95) and with footwear (ICC=0.83), during the static analysis with interrupted step. They were also consistent for the variable static weight bearing of the right lower limb (ICC=0.86) and left lower limb (ICC=0.82) barefooted with interrupted step, and with footwear with the feet aligned (ICC=0.82). In the left lower limb analysis with footwear, the maximum pressure also showed a satisfactory result (ICC=0.85). Other variables showed ICC variation between 0.25 and 0.74, considered unsatisfactory. The conclusions are that test-retest ICC were considered excellent for some static conditions, and inconsistent in the dynamic evaluation.

摘要
足底压力（plantar pressure）可用于足部的临床评估，能够反映受试者在功能活动过程中的足底负荷分布特征。当前临床已应用多种足底压力评估工具，且需对各工具的测量性能进行验证。重测信度（test-retest reliability）是用于评估测量结果可重复性的核心指标。本研究旨在分析正常发育（normal development, ND）儿童及青少年群体在静态与动态状态下的最大压力测量结果的重测信度。
本研究纳入11名性别均衡的正常发育儿童及青少年，年龄区间为6~17岁；受试者先后两次接受足底压力负重平台测试，测试体位为直立站姿，分别采用赤足与日常穿鞋两种测试状态，足部摆放方式涵盖自然放置（间断步姿，interrupted step）与双脚对齐两种模式。本研究采用组内相关系数（Intraclass correlation coefficients, ICC）开展统计分析，检验水准设定为α=0.05。
在采用间断步姿的静态分析中，赤足负重时的前足底（ICC=0.83）、后足底（ICC=0.95）以及穿鞋负重时的最大压力（ICC=0.83）均表现出良好的测量一致性。此外，采用间断步姿的赤足静态负重变量中，右下肢（ICC=0.86）与左下肢（ICC=0.82）的最大压力结果一致性良好；而在双脚对齐的穿鞋静态负重状态下，测量结果同样具有良好一致性（ICC=0.82）。在穿鞋状态下的左下肢负重分析中，最大压力测量结果同样表现优异（ICC=0.85）。其余变量的ICC值介于0.25~0.74之间，被认为一致性不佳。研究结论表明，部分静态负重场景下的重测信度ICC值表现优秀，但动态评估场景下的测量结果一致性较差。