Size counts – more evidence about multifidus in back pain

Size counts – more evidence about multifidus in back pain

Brett Vaughan, Lecturer, School of Biomedical & Health Sciences, Victoria University, Australia

A growing number of studies have identified that lumbar multifidus undergoes atrophy with low back pain with a predictable pattern of atrophy in an acute low back pain population. The location and the extent of atrophy of multifidus in a chronic low back pain population are still debated. Hides et al.1 investigated the size and symmetry of the multifidus bilaterally, comparing a chronic low back pain population (mean age 47 years) with a sample of convenience of people with no back pain (mean age 28 years). A secondary aim of this study was to compare the pattern of atrophy in different chronic low back pain presentations. Clinical records of 42 patients presenting to a hospital low back pain clinic were assessed with the clinical presentation data coded to indicate a bilateral or unilateral low back pain presentation. Cross-sectional area of the multifidus muscle was measured at levels L2–L5 using ultrasound imaging apparatus. Results of this study demonstrated a difference in multifidus cross-sectional area, with the chronic low back pain population demonstrating a decrease in diameter, particularly evident at the L4 and L5 vertebral levels. This result was not dependent upon the age of the patient. Unilateral low back pain patients demonstrated an asymmetry in the cross-sectional area at L4 and L5; however, this was not demonstrated in the bilateral low back pain or asymptomatic populations. The results of this study suggest that multifidus does atrophy in a chronic low back pain population and this is most evident at L4 and L5 levels indicating localized rather than generalised muscle change. Single sided pain is associated with asymmetry in patients with chronic low back pain. The authors suggest that their findings re-inforce the need for clinicians to provide exercise therapy that is designed for individual patients tailored to their impairments and that assessment should address comparisons between segmental levels and between sides.

Further research is required to contextualise the growing body of knowledge about specific muscle changes in patients with low back pain with current guidelines for treatment which suggest non-specific exercise interventions.


1. Hides J, Gilmore C, Stanton W, Bohlscheid E. Multifidus size and symmetry among chronic LBP and healthy asymptomatic subjects. Man Ther 2008;13:14–19.

International Journal of Osteopathic Medicine
Volume 11, Issue 3, September 2008, Pages 114-119