The Role of Back Muscle Dysfunctions in Chronic Low Back Pain: State-of-the-Art and Clinical Implications

Abstract

Changes in back muscle function and structure are highly prevalent in patients with chronic low back pain (CLBP). Since large heterogeneity in clinical presentation and back muscle dysfunctions exists within this population, the potential role of back muscle dysfunctions in the persistence of low back pain differs between individuals. Consequently, interventions should be tailored to the individual patient and be based on a thorough clinical examination taking into account the multidimensional nature of CLBP. Considering the complexity of this process, we will provide a state-of-the-art update on back muscle dysfunctions in patients with CLBP and their implications for treatment. To this end, we will first give an overview of (1) dysfunctions in back muscle structure and function, (2) the potential of exercise therapy to address these dysfunctions, and (3) the relationship between changes in back muscle dysfunctions and clinical parameters. In a second part, we will describe a framework for an individualised approach for back muscle training in patients with CLBP.

Paraspinal Muscle Changes in Individuals with and without Chronic Low Back Pain over a 4-Month Period: A Longitudinal MRI Study

“…Many studies have examined contributing factors to LBP, such as genetics, psychological factors, societal status, and physiological factors. However, there is no singular cause of LBP, making it difficult not only to study but also to manage [ 1 , 3 , 4 , 5 , 6 , 7 ]. For physiological factors, lumbar paraspinal musculature has recently been a major focus in LBP research.…”

“…For physiological factors, lumbar paraspinal musculature has recently been a major focus in LBP research. Studies have shown the benefit of targeting deep trunk and paraspinal muscles with exercise programs to reduce pain and atrophy [ 7 ]. However, the current understanding of the role of paraspinal musculature in the development, recurrence, and severity of LBP remains limited, especially when it comes to the natural progression (i.e., without intervention) of the paraspinal muscles’ structural changes over time.…”

“…However, the majority of human studies are cross-sectional in nature or include some form of intervention (i.e., therapeutic exercise, etc.) [ 7 ]. A recent meta-analysis found atrophy and increased fatty infiltration of the lumbar multifidus (LM) muscle in individuals with LBP, while the erector spinae (ES) and psoas major (PS) did not present with significant changes [ 4 ].…”

“…However, there are still inconsistencies within the literature. While many studies have reported atrophy of the LM, some have found no change and even hypertrophy, in addition to reporting increased LM fat infiltration [ 5 , 6 , 7 , 8 ]. Furthermore, the literature on the ES and other paraspinal muscles is very scarce [ 7 ].…”

“…While many studies have reported atrophy of the LM, some have found no change and even hypertrophy, in addition to reporting increased LM fat infiltration [ 5 , 6 , 7 , 8 ]. Furthermore, the literature on the ES and other paraspinal muscles is very scarce [ 7 ]. While LM asymmetry >10% was suggested to be associated with spinal pathology [ 9 ], this was also observed in healthy men, in addition to ES asymmetry ranging from 8.2% to 18.8% in a similar healthy population [ 10 ].…”