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）可用于足部临床评估，能够反映功能活动过程中足底负荷分布特征。当前临床使用多种评估工具，且需对其测量性能进行检验。重测信度（test-retest reliability）是用于评估测量重复性的指标。本研究旨在分析正常发育（normal development，ND）儿童与青少年在静态与动态状态下的最大压力测量值的重测信度。
招募11名男女各半、平均年龄6~17岁的正常发育儿童与青少年，分别在负重平台上以直立姿势接受两次评估：分别采用赤足与日常穿鞋两种状态，足部分别采取自然放置（中断步姿）与对齐摆放两种体位。采用组内相关系数（intraclass correlation coefficient，ICC）进行统计分析，显著性水平设定为α=0.05。
结果显示，在中断步姿的静态分析中，赤足负重前足区域（ICC=0.83）、赤足负重后足区域（ICC=0.95）以及穿鞋负重（ICC=0.83）的组内相关系数均表现出良好一致性。此外，中断步姿赤足状态下右下肢静态负重（ICC=0.86）、左下肢静态负重（ICC=0.82），以及足部对齐摆放的穿鞋状态下静态负重（ICC=0.82）的组内相关系数同样具有良好一致性；左下肢穿鞋状态下的最大压力测量值也取得了令人满意的结果（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。
本研究结论为：部分静态条件下的重测信度ICC值被评定为优异，而动态评估中的重测信度则表现出不一致性。