âStatistical shape analysis allows us to detect very localized changes in muscle shape associated with low back pain,â says lead author Yiming Xiao, assistant professor of computer science and software engineering. After taking into account variables such as age and gender, says Xiao, âthis study can help detect where specifically the muscles are degenerating. And it can help formulate a more targeted physiotherapy plan to strengthen those muscles and relieve suffering. “
Maryse Fortin, Assistant Professor in the Department of Health, Kinesiology and Applied Physiology, is co-author of the article, with Hassan Rivaz, Associate Professor and Research Chair in Electrical and Computer Engineering at Concordia University, Joshua Ahn, undergraduate student at Western and Terry Peters and Michele BattiÃ©, professors at Western. Currently, the inter-institute research collaboration is working on methods for analyzing medical images, including artificial intelligence technology that enables the automatic diagnosis and prognosis of painful spinal disorders, such as a herniated disc.
Two sides of the same muscle
Researchers are looking at unilateral lumbar disc herniation, which manifests as pain on the same side as the herniation. Essentially, it happens when one side of the intervertebral disc bulges out, which can irritate the nerve root. By examining participants with only pain on one side, they had access to pathological and healthy muscles in the same body, which allows for a clearer comparison as they can exclude complex variables such as lifestyle habits from consideration. .
âWe were able to find signature shape variations in the multifidus muscle between the painful and non-painful sides,â Xiao explains. âAnd compared to conventional methods of measuring muscle function, such as overall muscle size and fat infiltration, we found that our method was more sensitive to detecting differences. “
Definition of terms
Fortin says the technique also helped researchers determine whether the shape of the multifidus muscle was a biomarker for potential back pain. Previous studies have often had conflicting results because there was no uniformity in the analysis methodology. For example, researchers used different muscle segmentation protocols, so defining muscle groups would start and end in different places depending on the study.
The degenerative change in back muscles due to natural aging also complicates matters. This can confuse potential biomarkers and mask sources of pain, as a degenerative change does not necessarily lead to discomfort.
âHere with MRI, we have a three-dimensional view of the shape of the muscle, and it takes into account parameters that have not yet been studied,â she says. âWe found variations in forms from female to male, as well as associated with age and ontology. So this is really a new idea.
Read the article cited: “Statistical morphological analysis reveals characteristic asymmetry of paraspinal muscles in unilateral lumbar disc herniation. “