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Inter-rater reliability of trunk muscle morphometric analysis

Valentin, Stephanie; Yeates, Tobey DeMott; Licka, Theresia; Elliott, James


Tobey DeMott Yeates

Theresia Licka

James Elliott


BACKGROUND: Inter-rater reliability of generalised lumbar extensor muscle CSA has been identified, however, more detailed reliability metrics of individual trunk muscles are lacking.
OBJECTIVE: To report muscle volume and muscle fatty infiltrate (MFI) inter-rater reliability of individual trunk muscles between two novice assessors.
METHODS: Lumbar axial MRI scans from 10 healthy male participants were analysed. The muscles erector spinae (ES), multifidus (M), rectus abdominis (RA), and psoas (PS) were manually traced, region of interest quantified and muscle volume and MFI determined by both assessors. Agreement between the assessors was determined using intraclass correlation coefficients (3,1), Bland-Altman plots and Lin's concordance coefficient.
RESULTS: Good to excellent agreement was found for volume (ICC 0.77–0.96) and MFI (0.84–0.96) for all muscles on first evaluation, except for M volume, which required a second evaluation. Best agreement for muscle volume and MFI was found for ES (ICC 0.96).
CONCLUSIONS: First evaluation of muscle volume and MFI yields high to excellent inter-rater agreement, except for M, where further training and/or experience is required to achieve acceptable reliability outcomes. This may have clinical implications due to the relevance of M atrophy reported in patients with low back pain.


Valentin, S., Yeates, T. D., Licka, T., & Elliott, J. (2015). Inter-rater reliability of trunk muscle morphometric analysis. Journal of Back and Musculoskeletal Rehabilitation, 28(1), 181-190.

Journal Article Type Article
Publication Date Jan 26, 2015
Deposit Date Feb 8, 2023
Journal Journal of Back and Musculoskeletal Rehabilitation
Print ISSN 1053-8127
Electronic ISSN 1878-6324
Publisher IOS Press
Peer Reviewed Peer Reviewed
Volume 28
Issue 1
Pages 181-190
Keywords Inter-rater reliability, agreement, MRI, lumbar spine, muscle