Intermuscular relationship of human muscle fiber type proportions: slow leg muscles predict slow neck muscles.
Our aim in this study was to examine whether the muscle fiber type proportions in different muscles from the same individual are interrelated.
Samples were excised from five skeletal muscles in each of 12 human autopsy cases, and the fiber type proportions were determined by immunohistochemistry. We further examined the intermuscular relationship in fiber type proportion by reanalyzing three previously published data sets involving other muscles.
Subjects demonstrated a predominantly high or low proportion of type 1 fibers in all examined muscles, and the overall difference between individuals was statistically significant (P < 0.001). Accordingly, the type 1 fiber proportions in most muscles were positively correlated (median r = 0.42, range -0.03-0.80). Similar results were also obtained from the three reanalyzed data sets.
We suggest the existence of an across-muscle phenotype with respect to fiber type proportions; some individuals display generally faster muscles and some individuals slower muscles when compared with others.
SourceMuscle & nerve 45:4 2012 Apr pg 527-35
Fluorescent Antibody Technique
Muscle Fibers, Fast-Twitch
Muscle Fibers, Slow-Twitch
Pub Type(s)Journal Article
Research Support, Non-U.S. Gov't