Lugade Vipul, Kaufman Kenton
Motion Analysis Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA.
Motion Analysis Laboratory, Division of Orthopedic Research, Mayo Clinic, Rochester, MN 55905, USA.
Gait Posture. 2014;40(1):252-4. doi: 10.1016/j.gaitpost.2013.12.023. Epub 2013 Dec 27.
Stability during gait is maintained through control of the center of mass (CoM) position and velocity in relation to the base of support (BoS). The dynamic stability margin, or the interaction of the extrapolated center of mass with the closest boundary of the BoS, can reveal possible control errors during gait. The purpose of this study was to investigate a marker based method for defining the BoS, and compare the dynamic stability margin throughout gait in comparison to a BoS defined from foot pressure sensors. The root mean squared difference between these two methodologies ranged from 0.9 cm to 3.5 cm, when walking under four conditions: plantigrade, equinus, everted, and inverted. As the stability margin approaches -35 cm prior to contralateral heel strike, there was approximately 90% agreement between the two systems at this time point. Underestimation of the marker based dynamic stability margin or overestimation of the pressure based dynamic stability margin was due to inaccuracies in defining the medial boundary of the BoS. Overall, care must be taken to ensure similar definitions of the BoS are utilized when comparing the dynamic stability margin between participants and gait conditions.
步态稳定性通过控制质心（CoM）相对于支撑面（BoS）的位置和速度来维持。动态稳定裕度，即外推质心与支撑面最接近边界的相互作用，可揭示步态过程中可能存在的控制误差。本研究的目的是研究一种基于标记点定义支撑面的方法，并与基于足底压力传感器定义的支撑面相比，比较整个步态过程中的动态稳定裕度。在四种步态条件下行走时：全足底着地、马蹄足、外翻和内翻，这两种方法之间的均方根差在0.9厘米至3.5厘米之间。在对侧足跟触地前，当稳定裕度接近-35厘米时，此时两个系统之间的一致性约为90%。基于标记点的动态稳定裕度被低估或基于压力的动态稳定裕度被高估，是由于支撑面内侧边界定义不准确所致。总体而言，在比较不同参与者和步态条件下的动态稳定裕度时，必须注意确保使用相似的支撑面定义。
