Caravaggi Paolo, Rogati Giulia, Leardini Alberto, Ortolani Maurizio, Barbieri Mariachiara, Spasiano Chiara, Durante Stefano, Matias Alessandra B, Taddei Ulisses, Sacco Isabel C N
Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
Movement Analysis Laboratory, IRCCS Istituto Ortopedico Rizzoli, Bologna, Italy.
J Biomech. 2021 Nov 9;128:110711. doi: 10.1016/j.jbiomech.2021.110711. Epub 2021 Aug 27.
Static and dynamic measurements of the medial longitudinal arch (MLA) in the foot are critical across different clinical and biomechanical research fields. While MLA deformation can be estimated using skin-markers for gait analysis, the current understanding of the correlates between skin-marker based models and radiographic measures of the MLA is limited. This study aimed at assessing the correlation and accuracy of skin-marker based measures of MLA deformation with respect to standard clinical X-ray based measures, used as reference. 20 asymptomatic subjects without morphological alterations of the foot volunteered in the study. A lateral X-ray of the right foot of each subject was taken in monopodalic upright posture with and without a metatarsophalangeal-joint dorsiflexing wedge. MLA angle was estimated in the two foot postures and during gait using 16 skin-marker based models, which were established according to the marker set of a validated multi-segment foot kinematic protocol. The error of each model in tracking MLA deformation was assessed and correlated with respect to standard radiographic measurements. Estimation of MLA deformation was highly affected by the skin-marker models. Skin-marker models using the marker on the navicular tuberosity as apex of the MLA angle showed the smallest errors (about 2 deg) and the largest correlations (R = 0.64-0.65; p < 0.05) with respect to the radiographic measurements. According to the outcome of this study, skin-marker based definitions of the MLA angle using the navicular tuberosity as apex of the arch may provide a more accurate estimation of MLA deformation with respect to that from radiographic measures.
足部内侧纵弓（MLA）的静态和动态测量在不同的临床和生物力学研究领域至关重要。虽然可以使用皮肤标记物来估计MLA变形以进行步态分析，但目前对于基于皮肤标记物的模型与MLA的放射学测量之间的相关性了解有限。本研究旨在评估基于皮肤标记物的MLA变形测量相对于用作参考的标准临床X射线测量的相关性和准确性。20名足部无形态改变的无症状受试者自愿参与本研究。每位受试者的右脚在单足直立姿势下，分别在有和没有跖趾关节背屈楔形物的情况下拍摄侧位X射线。使用16种基于皮肤标记物的模型在两种足部姿势以及步态期间估计MLA角度，这些模型是根据经过验证的多节段足部运动学协议的标记集建立的。评估每个模型在跟踪MLA变形时的误差，并与标准放射学测量结果进行相关性分析。MLA变形的估计受到皮肤标记物模型的高度影响。以舟骨结节上标记物作为MLA角顶点的皮肤标记物模型显示出最小的误差（约2度），并且与放射学测量的相关性最大（R = 0.64 - 0.65；p < 0.05）。根据本研究结果，以舟骨结节作为足弓顶点的基于皮肤标记物的MLA角定义相对于放射学测量可能提供更准确的MLA变形估计。
