Biomedical Engineering Doctoral Program, Boise State University, Boise, ID, United States.
Mechanical and Biomedical Engineering Department, College of Engineering, Boise State University, Boise, ID, United States; Department of Kinesiology and Health Education, College of Education, The University of Texas at Austin, Austin, TX, United States.
J Biomech. 2024 Jan;162:111890. doi: 10.1016/j.jbiomech.2023.111890. Epub 2023 Dec 13.
Rolling is a critical step of infant development, encouraging muscle coordination and enabling independent exploration. Understanding muscle activity during infant rolling movements on a flat surface is necessary to more fully characterize how the rolling milestone is achieved. The purpose of this study was to determine infants' muscle activation throughout roll initiation for six previously established coordinated movements. Thirty-eight healthy infants (age: 6.5 ± 0.7 months; 23M/15F) were enrolled in this IRB-approved in-vivo biomechanics study. Surface electromyography sensors recorded muscle utilization from the erector spinae, abdominal muscles, quadriceps, and hamstrings while infants rolled. Each rolling movement was categorized as one of six roll types, and the mean muscle activity was analyzed. All roll types required initial activation of all measured muscle groups. Movements featuring axial rotation of the torso relative to the pelvis required highly active erector spinae muscles. Movements featuring trunk and hip flexion required highly active abdominal muscles. Infants used distinct coordinated muscle activations to achieve the six different roll types on a flat surface. A foundational understanding of the different muscle activation patterns required during infant rolling will provide crucial insight into motor development. This study quantified muscle coordination required of infants to achieve rolling on a firm flat surface. Previous research indicates that the mechanical environment in which an infant is placed impacts muscle activity and body position during normal lying. Therefore, future work should explore if mechanical environments that differ from a flat and firm surface also influence these coordinated movements and muscle activations.
滚动是婴儿发育的关键步骤，可促进肌肉协调性并实现独立探索。为了更全面地描述婴儿如何实现滚动这一里程碑，有必要了解他们在平面上滚动时的肌肉活动。本研究旨在确定婴儿在开始滚动时的肌肉激活情况，涉及之前确定的六种协调运动。38 名健康婴儿（年龄：6.5±0.7 个月；23 男/15 女）参与了这项经过机构审查委员会批准的体内生物力学研究。表面肌电图传感器记录了婴儿滚动时竖脊肌、腹肌、四头肌和腿筋的肌肉利用情况。每种滚动运动都分为六种滚动类型之一，并分析了平均肌肉活动。所有滚动类型都需要所有测量肌肉群的初始激活。与骨盆相比，躯体轴向旋转的运动需要竖脊肌高度活跃。涉及躯干和臀部弯曲的运动需要高度活跃的腹肌。婴儿在平面上实现六种不同滚动类型时，使用了独特的协调肌肉激活。对婴儿滚动时所需不同肌肉激活模式的基本了解将为运动发展提供关键见解。本研究量化了婴儿在坚硬平面上滚动所需的肌肉协调。先前的研究表明，婴儿所处的机械环境会影响他们正常躺着时的肌肉活动和身体姿势。因此，未来的研究应该探索与平面和坚硬表面不同的机械环境是否也会影响这些协调运动和肌肉激活。
