Hiroki Sato, PT, MS, Katsushi Kuniyasu, PT, PhD, Kenichi Kobara, PT, PhD, Yuji Okada, PT, Takaki Kawashima, PT, Atsushi Shinonaga, PT, Sayako Yamamoto, PT, PhD,
Masashi Yasunaga, MD, Kozo Hanayama, MD, PhD
Jpn J Compr Rehabil Sci 9: 66-72, 2018
Objective: This study aimed to establish ultrasonography
as a method of measuring the muscle cross-sectional area
and muscle intensity of the rectus femoris and to assess
its measurement accuracy.
Methods: Three testers measured the muscle crosssectional
area and muscle intensity of the rectus
femoris using ultrasonography in 16 healthy male
volunteers. Intra-rater and inter-rater reliabilities were
evaluated using the intraclass correlation coefficient
(ICC), and Bland-Altman (B-A) analysis was used to
confirm the systematic error and measure the minimum
detectable change.
Results: Intra-tester and inter-tester ICCs of the
muscle cross-sectional area and muscle intensity were
->0.9 and ->0.7, respectively. On B-A analysis, no
systematic error was observed in each measurement.
The minimum testable changes were 0.39 cm2 for the
intra-tester cross-sectional area, 0.15 cm2 for the intertester
cross-sectional area, 6.77 for the intra-tester
intensity, and 4.47 for the inter-tester intensity.
Conclusion: The muscle cross-sectional area and
muscle intensity of the rectus femoris can be measured
with high accuracy using this measurement method. In
addition, changes larger than the minimum detectable
change can be used as a true change in clinical efficacy
assessments.
Key words: ultrasonography, rectus femoris, muscle intensity, muscle cross-sectional area, measurement accuracy