Vastus lateralis architecture changes during pregnancy - a longitudinal study

While the incidence of falls has been described to increase with pregnancy, the mechanism behind this is unclear. Pregnancy associated changes in lower extremity muscle strength could be a possible factor influencing injury risk. Thus, the aim of this longitudinal study was to investigate muscle strength and architectural properties of the lower limbs in different stages of pregnancy and postpartum.

In nineteen pregnant women (30±4years) and fifteen non-pregnant controls (28±4years) muscle strength and architectural properties of the vastus lateralis muscle were assessed combining dynamometry, ultrasound, kinematic and electromyographic measurements. Body mass and body composition were determined using bioimpedance analysis. In the pregnant women, the measurements were conducted in the 16±4th (EP) and 29±4th week of pregnancy (LP) as well as in the 32±9th week postpartum (PP).

Muscle thickness and pennation angle of the fascicles significantly increased at LP, while muscle strengt...

尽管已有研究显示跌倒发生率随妊娠进程升高，但其背后的致病机制尚不明确。妊娠相关的下肢肌肉力量变化或许是影响损伤风险的潜在因素。因此，本项纵向研究旨在探究妊娠不同阶段及产后阶段下肢的肌肉力量与肌肉结构特性。

本研究纳入19名妊娠女性（年龄30±4岁）与15名非妊娠对照者（年龄28±4岁），通过测力法、超声成像、运动学检测及肌电图（electromyographic）测量相结合的方案，评估受试者股外侧肌（vastus lateralis）的肌肉力量与结构特性。采用生物电阻抗分析测定受试者体重与身体成分。针对妊娠女性，分别于妊娠16±4周（早期妊娠，EP）、29±4周（晚期妊娠，LP）以及产后32±9周（PP）完成上述测量。

妊娠晚期（LP）时，肌束的肌肉厚度与羽状角显著升高，而肌肉力量...