The effects of combined motor control and isolated extensor strengthening versus general exercise on paraspinal muscle morphology and function in patients with chronic low back pain: a randomised controlled trial protocol

Abstract

Background Exercise is a common approach for the management of patients with chronic non-specific low back pain (LBP). However, there is no clear mechanistic evidence or consensus on what type of exercise is more effective than others. While considerable evidence suggests a link between lumbar muscle health (e.g., atrophy and fatty infiltration) with functional deficits, it is unknown whether exercises targeting the lumbar spine can lead to noticeable improvements in muscle health and functional outcomes. The primary aim of this study is to compare the effect of combined motor control and isolated strengthening lumbar exercises (MC + ILEX) versus a general exercise group (GE) on multifidus muscle morphology (size and composition). Secondary aims include assessing the effect of the interventions on overall paraspinal muscle health, pain and disability, as well as psychological factors as possible effect modifiers. Methods A total of 50 participants with chronic non-specific LBP and moderate to severe disability, aged between 18 and 60, will be recruited from the local orthopaedic clinics and university community. Participants will be randomised (1:1) to either the MC + ILEX or GE group. Participants will undergo 24 individually supervised exercise sessions over a 12-week period. The primary outcome will be multifidus morphology (atrophy) and composition (fatty infiltration). Secondary outcomes will be muscle function (e.g., % thickness change during contraction), morphology, lumbar extension strength, pain intensity and disability. Potential treatment effect modifiers including maladaptive cognitions (fear of movement, catastrophizing), anxiety, depression, physical activity, and sleep quality will also be assessed. All measurements will be obtained at baseline, 6-week and 12-week; self-reported outcomes will also be collected at 24-week. Between-subjects repeated measure analysis of variance will be used to examine the changes in paraspinal muscle morphology over the different time points. Linear mixed models will be used to assess whether baseline scores can modify the response to the exercise therapy treatment. Discussion The results of this study will help clarify which of these two common interventions promote better results in terms of overall paraspinal muscle heath, back pain, disability and psychological factors in adults with chronic LBP. Trial registration NTCT04257253, registered prospectively on February 5, 2020.

Digital therapeutics-based lumbar core exercise for patients with low back pain: A prospective exploratory pilot study

“…These findings are consistent with previous studies that found a relationship between exercise therapy and core muscle enhancement. 61 – 63 We believe that the increase in CSA will become more significant with prolonged exercise treatment. We also hypothesize that the reinforced part of the muscle or the change in volume can vary depending on the type of exercise motion.…”

Trunk Muscle Activity and Ratio of Local Muscle to Global Muscle Activity during Supine Bridge Exercises under Unstable Conditions in Young Participants with and without Chronic Low Back Pain

“…Additionally, the motor control exercise intervention has also been shown to decrease the activity of the global trunk muscle group in trunk active movements, lifting, and trunk external perturbation tasks [ 46 , 47 , 48 ]. Recent randomized control trials have reported that motor control exercise reduces pain intensity and functional impairment in NSCLBP, in addition to changes in the morphology of the trunk local muscle groups [ 49 ]. Therefore, the strategy of exercise therapy for NSCLBP would be effective in activating the local muscles and inhibiting the global muscles.…”

The relationship between clinical examination measures and ultrasound measures of fascia thickness surrounding trunk muscles or lumbar multifidus fatty infiltrations: An exploratory study

“…Another study warranting attention showed decreased LuM MFI following a 16‐week free‐weight‐based resistance training programme where the emphasis was placed on maintaining a neutral lumbopelvic position during each exercise (Welch et al, 2015), which may provide some isolated activation of the LuM. Future sufficiently powered randomized controlled trials (Fortin et al, 2021) should clarify whether such isolated exercise modalities can reduce LuM MFI.…”