Original Article

Verification of the accuracy of measuring the muscle crosssectional area and muscle intensity of the rectus femoris using ultrasonography

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

Contents (volume 9)