Tuttle LJ, Ward SR, Lieber RL.
This report is a meta-analysis of the human muscle architecture literature that analyzes the number of muscles, number of subjects, and muscle fiber length coefficient of variation (CV) by body region.
Muscle fiber length data are used to make recommendations for dissection-based architectural study sample sizes.
An average of 9 ± 10 (mean ± SD) muscles and an average of 9 ± 5 subjects were reported in the 26 studies considered. Across all studies, average fiber length CV was highly variable (18% ± 5%). This shows that sample sizes required to achieve adequate power varies by anatomical region.
Studies involving muscle architecture should consider regional variability and effect size and determine sample size accordingly.
Full text (pdf)