Within- and between-session reliability of medial gastrocnemius architectural properties

McMahon, JJ; Turner, A; Comfort, P

Abstract

This study aimed to determine the within- and between-session reliability of medial gastrocnemius (MG)
architecture (e.g. muscle thickness (MT), fascicle length (FL) and pennation angle (PA)), as derived via
ultrasonography followed by manual digitization. A single rater recorded three ultrasound images of the relaxed
MG muscle belly for both legs of 16 resistance trained males, who were positioned in a pronated position with
their knees fully extended and the ankles in a neutral (e.g. 90°) position. A subset of participants (n = 11) were
retested under the same conditions ~48-72 hours after baseline testing. The same rater manually digitized
each ultrasound image on three occasions to determine MG MT, FL and PA before pooling the data accordingly
to allow for within-image (n = 96), between-image (n = 32) and between-session reliability (n = 22) to be
determined. Intraclass correlation coefficients (ICCs) demonstrated excellent within-image (ICCs = 0.99-1.00,
P < 0.001) and very good between-image (ICCs = 0.83-0.95, P < 0.001) and between-session (ICCs = 0.89-
0.95, P < 0.001) reliability for MT, FL and PA. Between-session coefficient of variation was low (≤ 3.6%) for
each architectural parameter and smallest detectible difference values of 10.6%, 11.4% and 9.8% were attained
for MT, FL and PA, respectively. Manually digitizing ultrasound images of the MG muscle at rest yields highly
reliable measurements of its architectural properties. Furthermore, changes in MG MT, FL and PA of ≥ 10.6%,
11.4% and 9.8% respectively, as brought about by any form of intervention, should be considered meaningful.

Citation

McMahon, J., Turner, A., & Comfort, P. (2016). Within- and between-session reliability of medial gastrocnemius architectural properties. Biology of Sport, 33(2), 185-188. https://doi.org/10.5604/20831862.1200511

• Journal Article Type: Article
• Acceptance Date: Mar 22, 2016
• Publication Date: Apr 27, 2016
• Deposit Date: May 13, 2016
• Journal: Biology of Sport
• Print ISSN: 0860-021X
• Publisher: Termedia Publishing
• Volume: 33
• Issue: 2
• Pages: 185-188
• DOI: https://doi.org/10.5604/20831862.1200511
• Publisher URL: http://dx.doi.org/10.5604/20831862.1200511