Poster Presentation 50th International Society for the Study of the Lumbar Spine Annual Meeting 2024

MULTIFIDUS MUSCLE ADAPTIONS AFTER 16 WEEKS OF HEAVY LOADED SPECIFIC EXERCISE PROGRAM IN PATIENTS WITH CHRONIC LOW BACK PAIN AND HERNIATED DISCS – A PROSPECTIVE MRI STUDY (#193)

Christoph Spang 1 2 , Witold Golonka 1 , Bruno Domokos 1 2 , Heiko Braun 3 , Christoph Raschka 2
  1. Private Orthopaedic Spine Center, Würzburg, Bavaria, Germany
  2. Institute for Sports Science, University of Würzburg, Würzburg, Bavaria, Germany
  3. Radiological Center, Höchberg, Bavaria, Germany

Introduction

Multifidus muscle atrophy and fatty infiltration are the key components of muscular changes in chronic back pain patients (Matheve et al., 2023). The underlying mechanisms are not fully understood and there is no clear information whether these degenerative processes can be properly addressed by exercise. Furthermore, most intervention studies have focused on unspecific low back pain. Studies on clinically more relevant symptoms such as disk herniations and with longer follow up time points are lacking.

Methods

In this prospective study, 21 patients (17 men, 4 women; mean age 45,9 years, range 27-70) with low back pain and radiculopathy symptoms for more than 3 months underwent a 16-week rehabilitation program (1-2x per week, 25 sessions in total) including specific heavy loaded machine based isolated lumbar extension resistance exercise (ILEX) and additional core strengthening exercises (Golonka et al., 2021). Pain (NRS, 0-10) and isometric strength (when possible) were measured, and MRI images were taken, before and after the intervention. Multifidus muscle total cross-sectional area (tCSA), lean muscle CSA (lCSA) and fraction of fat/soft tissue (FF) at three spinal levels (L3-S1) on both sides were quantified using T2 MRI images and analysing software. 

Results

Mean pain levels decreased from 4.75 ± 1.71 to 1.83 ± 1.85 (p<0.001). Isometric extension strength improved from 2.45 ± 0.75 Nm/kg bodyweight to 3.61 ± 0.68 Nm/kg (p<0.001). There was an increase of mean tCSA (p<0.001) and lCSA (p<0.01) for all patients at all three levels and at both sides. tCSA (in cm2) increased on average between 6.87 - 9.28% (L3 right: pre 6.77 ± 1.92, post 7.40 ± 2.02; L3 left: pre 6.45 ± 1.59, post 6.97 ± 1.73; L4 right: pre 9.50 ± 1.68, post 10.15 ± 1.73; L4 left: pre 9.33 ± 1.25, post 10.08 ± 1.44; L5 right: pre 10.54 ± 1.80, post 11.37 ± 1.78; L5 left: pre 10.57 ± 1.58, post 11.31 ± 1.66). The percentage of FF decreased between 10.28 - 18.08% (L3 right: pre 13.52 ± 5.42, post 11.77 ± 5.17; L3 left: pre 12.55 ± 6.83, post 10.42 ± 5.82; L4 right: pre 16.36 ± 8.56, post 13.80 ± 6.81; L4 left: pre 14.02 ± 4.91, post 12.05 ± 4.75; L5 right: pre 18.43 ± 9.38, post 15.10 ± 5.59; L5 left: pre 18.63 ± 6.42, post 16.71 ± 6.16). There was also an absolute reduction of FF at all segments and both sides. However, this decrease was not found significant and there were huge interindividual differences. Age did not correlate with the degree of absolute change in FF.


Discussion:

The results of this study indicate that 16 weeks of ILEX can substantially improve multifidus muscle quality in patients with specific spinal disorders. In all patients total and lean muscle areas increased, portions of fat decreased. The results on absolute reduction of FF are very promising and need to be re-evaluated in a larger cohort. The interindividual differences are interesting and show that the degree of muscle recovery might depend on interindividual factors other than age (e.g. pathology).

  1. Golonka W, Raschka C, Harandi VM, Domokos B, Alfredson H, Alfen FM, Spang C. Isolated Lumbar Extension Resistance Exercise in Limited Range of Motion for Patients with Lumbar Radiculopathy and Disk Herniation-Clinical Outcome and Influencing Factors. J Clin Med. 2021 May 30;10(11):2430.
  2. Matheve T, Hodges P, Danneels L. The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications. J Clin Med. 2023 Aug 24;12(17):5510.