Session Information
Session Type: Abstract Submissions (ARHP)
Background/Purpose: The importance of a physical approach in the management of axial spondyloarthritis (SpA) has been recognised for many years. It is supported by level 1a evidence including the 2008 Cochrane review into the effectiveness of physiotherapy in ankylosing spondylitis (AS), and by expert panel recommendations such as those of the Assessment of Spondyloarthritis group. The benefits of exercise have been shown to be still relevant even in patients who are stabilised with TNF blocking medication, and both subjective and measurable benefits can be much larger than that seen for other types of arthritis, and also non-inflammatory back pain. Despite this, there is a paucity of information about why exercise can be so beneficial, and about the specifics of exercise prescription. The aim of this study was therefore to provide pilot morphological data regarding any changes in lumbo-pelvic muscles, which may inform exercise prescription, and indicate further areas for research.
Methods: Twenty-three subjects with confirmed SpA or AS underwent an MRI scan of the lumbar spine and pelvis. The protocol aligned the transverse imaging plane with inferior aspect of the body of the 4th lumbar vertebra, in order to obtain measures of the cross sectional area (CSA) of specific lumbo-pelvic muscles. The digitised images were analysed by computer software to determine muscle size, symmetry and ratio of contractile to non-contractile tissue, using previously validated methods.
Results: Non-contractile tissue was observed within the fascial boundaries of the paraspinal muscles to some degree in all subjects. These changes were graded according to a previously validated five point scale as follows:
|
|
Lumbar Multifidus |
Lumbar Erector Spinae |
||
|
Number of Spinal Levels |
Subjects ≥ Grade 2 – n |
Subjects ≥ Grade 2 – % |
Subjects ≥ Grade 2 – n |
Subjects ≥ Grade 2 – % |
|
0 |
0 |
0% |
3 |
13% |
|
1 |
8 |
35% |
8 |
35% |
|
2 |
8 |
35% |
8 |
35% |
|
3 |
3 |
13% |
1 |
13% |
|
4 |
1 |
4% |
1 |
13% |
|
5 |
3 |
13% |
n/a |
n/a |
The prevalence of non-contractile tissue was not associated with measures such as body mass or metrology indices, but was inversely associated with self-reported physical activity levels (p). Additional measures of lumbar multifidus CSA at L5/S1 level demonstrated a mean functional to total muscle CSA of only 61% (range 18-88%).
Conclusion: This study provides new information on the morphology of the lumbo-pelvic muscles in SpA, and also confirms the applicability of this methodology in inflammatory back pain. The association of reduced functional muscle area with lower activity levels supports the concept of a specifically designed exercise intervention. Similar findings have been noted in non-inflammatory back pain, but points of difference are highlighted that need exploring. The study has therefore revealed some research gaps regarding muscle changes in SpA, which may be either secondary to the disease or part of the process.
Disclosure:
J. Millner,
None;
J. A. Hides,
None;
P. Lewis,
None;
J. Zochling,
None.
ACR Meeting Abstracts - https://acrabstracts.org/abstract/the-lumbo-pelvic-muscles-and-axial-spondyloarthritis-a-pilot-observational-study/