Sargent Barbara, Reimann Hendrik, Kubo Masayoshi, Fetters Linda
Division of Biokinesiology & Physical Therapy, Herman Ostrow School of Dentistry, University of Southern California, 1540 E. Alcazar St., CHP 155, Los Angeles, CA 90033, USA.
Department of Kinesiology, Temple University, Philadelphia, PA, USA.
Infant Behav Dev. 2017 Nov;49:129-140. doi: 10.1016/j.infbeh.2017.08.009. Epub 2017 Sep 8.
The purpose of this study is to investigate changes in leg joint coordination, intersegmental dynamics, and their relation in infants born preterm (PT) during the first months of life. Kicking actions were analyzed of 11 infants born PT at 6 and 15-weeks corrected age (CA) using three-dimensional kinematics and kinetics; results were compared to the kicking actions of 10 infants born full-term (FT). Both groups changed from a predominately in-phase coordination at 6-weeks CA to a less in-phase coordination at 15-weeks CA, however, at 6-weeks CA, infants born PT demonstrated less in-phase coordination of their ankle joints with their hip and knee joints. Between groups and across ages, both groups demonstrated consistent net and partitioned joint torque profiles, however, at 6-weeks CA infants born PT demonstrated more complex patterns of torque components. In both groups, less in-phase hip-knee coordination was associated with reduced active knee muscle torque and increased passive knee torques, however, passive knee torques had a greater influence on the kicks of infants born PT at 6-weeks CA. At 6-weeks CA, infants born PT, compared to FT, generated kicks with less in-phase hip-knee coordination, hip excursion, hip angular velocity, and hip muscle torque impulse. By 15-weeks CA, differences resolved in all variables except hip muscle torque impulse. These results highlight a different trajectory of leg joint coordination and torque production for infants born PT compared to FT.
本研究的目的是调查早产（PT）婴儿在出生后的头几个月中腿部关节协调性、节段间动力学及其关系的变化。使用三维运动学和动力学方法分析了11名PT婴儿在矫正年龄（CA）6周和15周时的踢腿动作；结果与10名足月（FT）出生婴儿的踢腿动作进行了比较。两组婴儿均从CA 6周时主要的同相协调转变为CA 15周时较少的同相协调，然而，在CA 6周时，PT出生的婴儿踝关节与髋关节和膝关节的同相协调性较差。在组间和不同年龄阶段，两组婴儿的净关节扭矩和分区关节扭矩曲线均保持一致，然而，在CA 6周时，PT出生的婴儿扭矩分量模式更为复杂。在两组中，髋关节-膝关节协调性降低与主动膝关节肌肉扭矩降低和被动膝关节扭矩增加有关，然而，在CA 6周时，被动膝关节扭矩对PT出生婴儿的踢腿动作影响更大。在CA 6周时，与FT出生的婴儿相比，PT出生的婴儿踢腿时髋关节-膝关节协调性、髋关节偏移、髋关节角速度和髋关节肌肉扭矩冲量均较低。到CA 15周时，除髋关节肌肉扭矩冲量外，所有变量的差异均消失。这些结果突出了PT出生婴儿与FT出生婴儿相比，腿部关节协调性和扭矩产生的不同轨迹。
