Mechanical Engineering Department, Stanford University BioMotion Laboratory, 496 Lomita Mall, Durand 061, Stanford, California 94305, USA.
J Orthop Res. 2013 Sep;31(9):1414-22. doi: 10.1002/jor.22390. Epub 2013 Jun 4.
There is a need to understand how obesity and aging interact to cause an increased risk of medial knee osteoarthritis (OA). This study tested whether the knee adduction and flexion moments increase with age in healthy normal-weight and obese adults, as well as the mechanism of this increase. We analyzed whether ground reaction force magnitude, knee alignment, step width, toe-out angle, body volume distribution, and limb position (knee position relative to the pelvis center) are associated with the adduction moment and whether these variables also change with age. Ninety-six healthy volunteers (60 normal-weight and 36 obese) were tested using marker-based gait analysis; knee alignment was based on marker positions during quiet standing. Adduction moment increased with age in obese (R(2) = 0.19), but not in normal-weight individuals (R(2) = 0.01); knee flexion moment did not change with age in either group. In the obese, only knee alignment and limb position were related to the adduction moment (R(2) = 0.19 and 0.51), but only limb position changed with age (R(2) = 0.26). The resulting increase in adduction moment suggests greater medial compartment loads, which may combine with elevated levels of inflammation to contribute to the increased risk of medial OA in this population.
需要了解肥胖和衰老如何相互作用导致内侧膝关节骨关节炎（OA）风险增加。本研究测试了在健康的正常体重和肥胖成年人中，膝关节内收和弯曲力矩是否随年龄增长而增加，以及这种增加的机制。我们分析了地面反作用力大小、膝关节对线、步宽、外展角、身体体积分布以及肢体位置（膝关节相对于骨盆中心的位置）是否与内收力矩有关，以及这些变量是否也随年龄变化。使用基于标记的步态分析测试了 96 名健康志愿者（60 名正常体重和 36 名肥胖）；膝关节对线基于静立位时的标记位置。肥胖者的内收力矩随年龄增长而增加（R(2) = 0.19），但正常体重者则没有（R(2) = 0.01）；两组的膝关节弯曲力矩都没有随年龄变化。在肥胖者中，只有膝关节对线和肢体位置与内收力矩有关（R(2) = 0.19 和 0.51），但只有肢体位置随年龄变化（R(2) = 0.26）。内收力矩的增加表明内侧间室负荷增加，这可能与炎症水平升高相结合，导致该人群中内侧 OA 风险增加。
