Kinematic data for the Concurrent repeatability and reproducibility analysis of four gait models for foot-ankle complex

Multi-segment models of the foot have been proposed in the past years to overcome limitations imposed by oversimplified traditional approaches used to describe foot kinematics, but they have been only partially validated and never compared. This paper presents a unique comparative assessment of the four most widely adopted foot kinematic models and aims to provide a guidance for the clinical interpretation of their results. Sensitivity of the models to differences between treadmill and overground walking was tested in nine young healthy adults using a 1D paired <i>t</i>-test. Repeatability was assessed by investigating the joint kinematics obtained when the same operator placed the markers on thirteen young healthy adults in two occasions. Reproducibility was then assessed using data from three randomly selected participants, asking three operators to repeat the marker placement three times. The analyses were performed on sagittal kinematics using curve similarity and correlation indices (Linear Fit Method) and absolute differences between selected points. Differences between treadmill and overground gait were highlighted by all the investigated models. The two most repeatable and reproducible investigated models had average correlations higher than 0.70, with the lowest values (0.56) obtained for the midfoot. Averaged correlations were always higher than 0.74 for the former and 0.70 for the latter, with the lowest obtained for the midfoot (0.64 and 0.51). For all investigated models, foot kinematics generally showed low repeatability: normative bands must be adopted with caution when used for comparison with patient data.

近年来，学界已提出多节段足部模型，以克服传统简化方法在描述足部运动学（foot kinematics）时存在的局限性，但此类模型仅得到了部分验证，且从未开展过系统性对比研究。本研究针对目前应用最广泛的四款足部运动学模型，开展了首次对比评估，旨在为临床解读其分析结果提供科学参考依据。本研究招募9名健康青年受试者，采用一维配对t检验（1D paired t-test），评估了各模型对跑步机行走与地面行走差异的敏感性。通过同一操作者分两次为13名健康青年受试者粘贴运动捕捉标记点后获取的关节运动学数据，评估了各模型的重复性（repeatability）。随后，本研究选取3名随机招募的受试者，由3名操作者分别重复三次完成标记点粘贴，以此评估各模型的复现性（reproducibility）。本研究针对矢状面运动学（sagittal kinematics）数据开展分析，采用曲线相似度与相关指数（线性拟合方法，Linear Fit Method）以及选定特征点的绝对差值作为评价指标。所有受试模型均能显著体现出跑步机步态与地面步态之间的差异。两款在重复性与复现性均表现最优的受试模型，其平均相关系数均高于0.70，其中足中段的相关系数最低，仅为0.56。其中，两款模型的平均相关系数分别始终高于0.74与0.70，二者最低值均出现在足中段，分别为0.64与0.51。对于所有受试模型而言，足部运动学的整体重复性均较低：因此，在将正常参考带（normative bands）用于患者数据对比分析时，需谨慎应用此类参考标准。