Morphology versus function: the relationship between lumbar multifidus intramuscular adipose tissue and muscle function among patients with low back pain

Edward C Le Cara; Robin L Marcus; Alasdair R Dempsey; Martin D Hoffman; Jeffrey J Hebert

doi:10.1016/j.apmr.2014.04.019

Morphology versus function: the relationship between lumbar multifidus intramuscular adipose tissue and muscle function among patients with low back pain

Arch Phys Med Rehabil. 2014 Oct;95(10):1846-52. doi: 10.1016/j.apmr.2014.04.019. Epub 2014 May 9.

Authors

Edward C Le Cara¹, Robin L Marcus², Alasdair R Dempsey³, Martin D Hoffman⁴, Jeffrey J Hebert⁵

Affiliations

¹ Rocky Mountain University of Health Professions, Provo, UT.
² Department of Physical Therapy, University of Utah, Salt Lake City, UT.
³ School of Psychology and Exercise Science, Murdoch University, Murdoch, WA, Australia.
⁴ Department of Physical Medicine and Rehabilitation, Department of Veterans Affairs, Northern California Health Care System, Sacramento, CA; University of California Davis Medical Center, Sacramento, CA.
⁵ School of Psychology and Exercise Science, Murdoch University, Murdoch, WA, Australia. Electronic address: J.Hebert@Murdoch.edu.au.

PMID: 24814564
DOI: 10.1016/j.apmr.2014.04.019

Abstract

Objective: To explore the bivariate and multivariate relations between fatty degeneration of the lumbar multifidus muscle (LMM) and LMM function among patients with low back pain (LBP).

Design: Cross-sectional clinical study.

Setting: Hospital.

Participants: Patients with LBP (N=70) referred for lumbar spine magnetic resonance imaging.

Interventions: Not applicable.

Main outcome measures: LMM morphology and function were measured at the L4/L5 and L5/S1 spinal levels bilaterally. Quantitative measures of LMM intramuscular adipose tissue (IMAT) were derived from T1-weighted magnetic resonance images. Function was assessed with ultrasound imaging by measuring change in LMM thickness during a submaximal contraction task. The study participants self-reported their level of LBP-related disability (Modified Oswestry Index), pain intensity (numerical pain rating scale), and physical activity (International Physical Activity Questionnaire). Bivariate and multivariate relations between LMM morphology and function were explored with correlational and hierarchical linear regression analyses, respectively. Additionally, we explored for possible covariates with potential to modify the relation between LMM IMAT and function.

Results: There were 70 participants (12 women) enrolled in the study (mean age, 45.4±11.9y). A high level of physical activity was reported by 45.5% of participates. Age, sex, and physical activity level demonstrated variable relations with LMM IMAT and LMM function. There were no significant bivariate or multivariate relations between LMM IMAT and LMM function.

Conclusions: We observed higher levels of physical activity and LMM function and less LMM IMAT than previous studies involving patients with LBP. There was no relation between LMM morphology and function in this cohort of patients with LBP. Issues specific to LMM measurement and recommendations for future research are discussed.

Keywords: Adipose tissue; Low back pain; Magnetic resonance imaging; Paraspinal muscles; Rehabilitation; Ultrasonography.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adipose Tissue / pathology*
Adult
Cross-Sectional Studies
Disability Evaluation
Female
Humans
Low Back Pain / pathology*
Low Back Pain / physiopathology*
Lumbosacral Region
Magnetic Resonance Imaging
Male
Middle Aged
Motor Activity
Multivariate Analysis
Muscle Contraction
Pain Measurement
Paraspinal Muscles / diagnostic imaging
Paraspinal Muscles / pathology*
Paraspinal Muscles / physiopathology*
Self Report
Ultrasonography