Growth and development of human muscle: A quantitative morphological study of whole vastus lateralis from childhood to adult age
Article first published online: 13 OCT 2004
Copyright © 1992 John Wiley & Sons, Inc.
Muscle & Nerve
Volume 15, Issue 3, pages 404–409, March 1992
How to Cite
Lexell, J., Sjöström, M., Nordlund, A.-S. and Taylor, C. C. (1992), Growth and development of human muscle: A quantitative morphological study of whole vastus lateralis from childhood to adult age. Muscle Nerve, 15: 404–409. doi: 10.1002/mus.880150323
- Issue published online: 13 OCT 2004
- Article first published online: 13 OCT 2004
- Manuscript Accepted: 19 MAR 1991
- physiological adaptation
The mechanisms underlying the increase in volume of muscle tissue, and the functional development of muscle fibers from childhood through adolescence to adult age, have been studied. Cross sections of autopsied whole vastus lateralis muscle from 22 previously physically healthy males, 5 to 37 years of age, were prepared enzyme histochemically (myofibrillar ATPase) and examined morphometrically. The data obtained on muscle crosssectional area, size, total number, and proportion of type 1 (slow-twitch) and type 2 (fast-twitch) fibers were analyzed using linear regression techniques. The results show that the increase in muscle cross-sectional area from childhood to adult age is caused by an increase in mean fiber size. This is accompanied by a functional development of the fiber population: the proportion of type 2 fibers increases significantly from the age of 5 (approx. 35%) to the age of 20 (approx. 50%), which, in the absence of any discernible effect on the total number of fibers, is most likely caused by a transformation of type 1 to type 2 fibers.