Simunic Bostjan, Degens Hans, Zavrsnik Jernej, Koren Katja, Volmut Tadeja, Pisot Rado
Science and Research Centre Koper, Institute for Kinesiology Research, Koper, Slovenia.
Manchester Metropolitan University, Institute for Biophysical and Clinical Research into Human Movement, Alsager, United Kingdom of Great Britain and Northern Ireland.
Int J Sports Med. 2017 Sep;38(9):659-665. doi: 10.1055/s-0043-110679. Epub 2017 Jul 13.
While there are numerous data on the skeletal muscle fiber type composition in adults, little is known about the changes in fiber type composition and contractile properties during maturational growth in children. Using noninvasive tensiomyography, we measured contraction time (Tc), an indirect estimate of the myosin heavy chain I (MHC-I) proportion, to assess the longitudinal changes of the biceps brachii (BB), biceps femois (BF), vastus lateralis (VL), and erector spinae (ES) muscles in 53 boys and 54 girls. The children were 9 years at the start of the study and returned for 5 follow-up measurements until the age of 14 years. The ES has the shortest and the BF has the longest Tc. The VL and ES of boys have shorter Tc than those of girls. When applying the relationship between proportion of MHC-I and Tc established in adults to children's TMG data, we found a slow-to-fast transition in the VL between, at least, the ages of 6 to 10 years, when it stabilized to adult proportions. Regular participation in sports was associated with a faster BF, but not in the VL. Our data represents a first non-invasive indication of the developmental changes in muscle fiber type composition in children.
虽然有大量关于成年人骨骼肌纤维类型组成的数据，但对于儿童成熟生长过程中纤维类型组成和收缩特性的变化却知之甚少。我们使用非侵入性张力肌电图，测量收缩时间（Tc）（肌球蛋白重链I（MHC-I）比例的间接估计值），以评估53名男孩和54名女孩肱二头肌（BB）、股二头肌（BF）、股外侧肌（VL）和竖脊肌（ES）的纵向变化。研究开始时儿童为9岁，并进行了5次随访测量，直至14岁。ES的Tc最短，BF的Tc最长。男孩的VL和ES的Tc比女孩的短。当将在成年人中建立的MHC-I比例与Tc之间的关系应用于儿童的张力肌电图数据时，我们发现VL至少在6至10岁之间存在从慢到快的转变，之后稳定在成人比例。经常参加运动与BF收缩速度加快有关，但与VL无关。我们的数据首次非侵入性地表明了儿童肌肉纤维类型组成的发育变化。
