Catena Robert D, Bailey Joshua P, Campbell Nigel, Music Hallie E
Washington State University, 101 Physical Education Building, Pullman, WA 99164-1410, United States.
University of Idaho, 875 Perimeter Drive MS 2401, Moscow, ID 83844-2401, United States.
Clin Biomech (Bristol). 2019 Jul;67:107-114. doi: 10.1016/j.clinbiomech.2019.05.014. Epub 2019 May 9.
The stand-to-sit motion has been linked to falls during pregnancy. It is also used in the clinical evaluation of functional performance. The physical and physiological changes during pregnancy may necessitate a change in stand-to-sit kinematic performance. Therefore, this study was conducted to evaluate the longitudinal changes to stand-to-sit kinematics during pregnancy.
Fifteen pregnant women were tested in 4-week intervals from 16 weeks to 36 weeks gestational age. They performed a 60-second trial of semi-continuous stand-to-sit motion. Sagittal plane motions at the ankle, knee, spine, and shoulders were measured. Additionally, three-dimensional hip motion was measured. Discrete variables (e.g. range of motion) and joint coordinations (through vector coding) were analyzed over time through a linear mixed model analysis.
The results indicate a shift away from sagittal hip motion throughout pregnancy. Hip range of motion and standing angle changed in favor of spine motion. Joint coordination shifted from hip dominant to spine- and shoulder-dominate coordination just before the start of sitting motion. Hip-knee joint coordination just before seat contact shifted from hip to a knee-dominant motion during pregnancy.
Discrete variable changes in the entire stand-to-sit motion seem to be driven by initial standing posture related to an increase in gestational lordosis. Likewise, standing joint coordination shift to upper body motion can be attributed to gestational lordosis limiting functional ability around the hip. The shift in motion away from the hip may provide insight into why both fall rates and low back pain rates increase during stand-to-sit during pregnancy.
从站立到坐下的动作与孕期跌倒有关。它也用于功能表现的临床评估。孕期的身体和生理变化可能需要改变从站立到坐下的运动学表现。因此，本研究旨在评估孕期从站立到坐下的运动学的纵向变化。
15名孕妇在孕16周龄至36周龄期间每隔4周接受测试。她们进行了60秒的半连续从站立到坐下的动作试验。测量了踝关节、膝关节、脊柱和肩部在矢状面的运动。此外，还测量了三维髋关节运动。通过线性混合模型分析随时间分析离散变量（如运动范围）和关节协调性（通过矢量编码）。
结果表明，在整个孕期，髋关节矢状面运动减少。髋关节运动范围和站立角度发生变化，有利于脊柱运动。在开始坐下动作前，关节协调性从以髋关节为主转变为以脊柱和肩部为主的协调性。在孕期，即将接触座椅前，髋膝关节协调性从以髋关节为主转变为以膝关节为主的运动。
整个从站立到坐下动作中的离散变量变化似乎是由与妊娠腰椎前凸增加相关的初始站立姿势驱动的。同样，站立时关节协调性向上半身运动的转变可归因于妊娠腰椎前凸限制了髋关节周围的功能能力。运动从髋关节转移可能有助于解释为什么孕期从站立到坐下时跌倒率和腰痛率都会增加。
