Relationships between muscle electrical activity and the control of inter-vertebral motion during a forward bending task

The association between morphological characteristics of paraspinal muscle and spinal disorders

BACKGROUND

Spinal disorders affect millions of people worldwide, and can cause significant disability and pain. The paraspinal muscles, located on either side of the spinal column, play a crucial role in the movement, support, and stabilization of the spine. Many spinal disorders can affect paraspinal muscles, as evidenced by changes in their morphology, including hypertrophy, atrophy, and degeneration.

OBJECTIVES

The objectives of this review were to examine the current literature on the relationship between the paraspinal muscles and spinal disorders, summarize the methods used in previous studies, and identify areas for future research.

METHODS

We reviewed studies on the morphological characteristics of the paravertebral muscle and discussed their relationship with spinal disorders, as well as the current limitations and future research directions.

RESULTS

The paraspinal muscles play a critical role in spinal disorders and are important targets for the treatment and prevention of spinal disorders. Clinicians should consider the role of the paraspinal muscles in the development and progression of spinal disorders and incorporate assessments of the paraspinal muscle function in clinical practice.

CONCLUSION

The findings of this review highlight the need for further research to better understand the relationship between the paraspinal muscles and spinal disorders, and to develop effective interventions to improve spinal health and reduce the burden of spinal disorders.

Relationship between the morphology and composition of the lumbar paraspinal and psoas muscles and lumbar intervertebral motion in people with chronic low back pain

Muscles of the lumbar spine play an important role in controlling segmental intervertebral motion. This study aimed to evaluate the association between lumbar intervertebral motion and changes in lumbar morphology/composition in people with chronic low back pain (CLBP). A sample of 183 patients with CLBP participated in this cross-sectional study. Participants underwent lumbar flexion-extension X-Rays to determine vertebral motion (translational and/or rotational motion) of lumbar levels (L1-L2 to L5-S1) and lumbar spine Magnetic Resonance Imaging (MRI) to quantify total and functional cross-sectional areas (CSAs) and asymmetry of the multifidus, lumbar erector spinae and psoas muscles. The relationship between morphology/composition of the muscles and lumbar intervertebral motion was investigated. Smaller total and functional CSAs of the multifidus and greater CSAs of the lumbar erector spinae muscle were observed in participants with greater intervertebral motion. Muscle asymmetry was observed at different lumbar vertebral levels. The greatest amount of translational intervertebral motion was observed at the L3-L4 level, while the greatest amount of rotational translation occurred at the L4-5 level. Associations were observed between the morphology of the paraspinal muscles at the vertebral levels adjacent to the L3-L4 level and the increased intervertebral motion at this level. Relationships between measures of muscle morphology/composition and increased segmental vertebral motion were observed. The results may provide a plausible biological reason for the effectiveness of rehabilitating deficient paraspinal muscles in a subset of people with CLBP. This article is protected by copyright. All rights reserved.

A Reference Database of Standardised Continuous Lumbar Intervertebral Motion Analysis for Conducting Patient-Specific Comparisons

Lumbar instability has long been thought of as the failure of lumbar vertebrae to maintain their normal patterns of displacement. However, it is unknown what these patterns consist of. Research using quantitative fluoroscopy (QF) has shown that continuous lumbar intervertebral patterns of rotational displacement can be reliably measured during standing flexion and return motion using standardised protocols and can be used to assess patients with suspected lumbar spine motion disorders. However, normative values are needed to make individualised comparisons. One hundred and thirty-one healthy asymptomatic participants were recruited and performed guided flexion and return motion by following the rotating arm of an upright motion frame. Fluoroscopic image acquisition at 15fps was performed and individual intervertebral levels from L2-3 to L5-S1 were tracked and analysed during separate outward flexion and return phases. Results were presented as proportional intervertebral motion representing these phases using continuous means and 95%CIs, followed by verification of the differences between levels using Statistical Parametric Mapping (SPM). A secondary analysis of 8 control participants matched to 8 patients with chronic, non-specific low back pain (CNSLBP) was performed for comparison. One hundred and twenty-seven asymptomatic participants’ data were analysed. Their ages ranged from 18 to 70 years (mean 38.6) with mean body mass index 23.8 kg/m² 48.8% were female. Both the flexion and return phases for each level evidenced continuous change in mean proportional motion share, with narrow confidence intervals, highly significant differences and discrete motion paths between levels as confirmed by SPM. Patients in the secondary analysis evidenced significantly less L5-S1 motion than controls (p < 0.05). A reference database of spinal displacement patterns during lumbar (L2-S1) intersegmental flexion and return motion using a standardised motion protocol using fluoroscopy is presented. Spinal displacement patterns in asymptomatic individuals were found to be distinctive and consistent for each intervertebral level, and to continuously change during bending and return. This database may be used to allow continuous intervertebral kinematics to drive dynamic models of joint and muscular forces as well as reference values against which to make patient-specific comparisons in suspected cases of lumbar spine motion disorders.

Dynamic interactions between lumbar intervertebral motion segments during forward bending and return

Continuous dynamic multi-segmental studies of lumbar motion have added depth to our understanding of the biomechanics of back pain, but few have attempted to continuously measure the proportions of motion accepted by individual levels. This study attempted to compare the motion contributions of adjacent lumbar levels during an active weight bearing flexion and return protocol in chronic, non-specific low back pain (CNSLBP) patients and controls using quantitative fluoroscopy (QF). Eight CNSLBP patients received QF during guided standing lumbar flexion. Dynamic motion sharing of segments from L2 to S1 were calculated and analysed for interactions between levels. Eight asymptomatic controls were then matched to the 8 patients for age and sex and their motion sharing patterns compared. Share of intersegmental motion was found to be consistently highest at L2-L3 and L3-L4 and lowest at L5-S1 throughout the motion in both groups, with the exception of maximum flexion where L4-L5 received the greatest share. Change in motion sharing occurred throughout the flexion and return motion paths in both participant groups but tended to vary more at L4-L5 in patients (p < 0.05). In patients, L5-S1 provided less angular range (p < 0.05) and contributed less at maximum bend (p < 0.05), while L3-L4, on average over the bending sequence, provided a greater share of motion (p < 0.05). Intervertebral motion sharing inequality is therefore a normal feature during lumbar flexion. However, in patients, inequality was more pronounced, and variability of motion share at some levels increased. These effects may result from differences in muscular contraction or in the mechanical properties of the disc.

Effect of Global Postural Reeducation Exercise on Pain and Hip Muscle Flexibility in Patients with Chronic Low Back Pain and Movement Control Dysfunction

Introduction: Patients with non-specific low back pain (NSLBP) and movement control dysfunction demonstrate alternation in hip muscles flexibility and spinal movement patterns. Therapeutic modalities that augment hip muscles flexibility could help these patients. The aim of this study was to investigate the effect of global postural reeducation (GPR) on pain and hip muscle flexibility in patients with NSLBP and movement control dysfunction. Materials and Methods: A total of 27 men with a mean age of 31.21±2.5147 years, height of 166.44±6.11 cm, and weight of 64.21±5.25 kg participated in this study. The visual analogue scale (VAS) was used to evaluate pain. The flexibility of hip muscles (rectus femoris, tensor fasciae latae, external rotators and hamstring) was measured using universal goniometer. All data were assessed at baseline and after the intervention. The Shapiro-Wilk test and paired t test were used for statistical analysis at significance level of P=0.05. Results: Our results revealed a decline in pain (P<0.004) and an increase in the flexibility of the hamstring muscles in the right (P<0.003) and left (P<0.003) legs. There were no statistically significant differences in the flexibility of rectus femoris muscle, external rotators, and tensor fasciae latae. Conclusion: The results suggest that GPR had a significant effect on the level of pain. Further, it affected the flexibility of hamstring muscles in legs. Using GPR is recommended for pain relief and improving the flexibility of hamstring muscles in patients with NSLBP.