Effect of evidence-based trunk stability exercises on the thickness of the trunk muscles

A dose response analysis of exercise prescription variables for lateral abdominal muscle thickness and activation: A systematic review

BACKGROUND

Various exercise programs are used to treat lateral abdominal muscle (LAM) impairments in people with low back pain. Factors comprising these programs include exercise type, session time, frequency, and program duration. However, specific clinical guidance about optimal exercise prescription is lacking.

OBJECTIVES

To perform a dose-response analysis on exercise prescription variables for LAM thickness and activation as measured by ultrasound imaging.

DESIGN

Systematic review METHOD: Databases were searched from their inception for studies examining the association between exercise interventions and LAM thickness/activation measured by ultrasound imaging in healthy individuals. Risk of bias was assessed using the Joanna Brigg's Institute critical appraisal tools. For each muscle, subgroup analyses were performed to determine the dose response of exercise prescription variables for LAM thickness and activation. Where there was insufficient data for subgroup analyses, data was narratively synthesised.

RESULTS

Fourteen studies comprising 395 participants were included. Statistical and narrative synthesis revealed specific local abdominal exercises, programs from four weeks duration, three sessions per week and sessions of ≥30 min were associated with greatest improvements to LAM thickness. Only the variables exercise type, program duration and session frequency showed a significant between groups difference for the subgroup analysis. The main limitation was inability to perform subgroup analyses for all variables across all muscles measured at rest and during contraction, due to non-reporting of data.

CONCLUSION

This review provides preliminary guidance to practitioners on how the LAM respond to different exercise dosages. Future research should trial these findings.

Inconsistent descriptions of lumbar multifidus morphology: A scoping review

Background

Lumbar multifidus (LM) is regarded as the major stabilizing muscle of the spine. The effects of exercise therapy in low back pain (LBP) are attributed to this muscle. A current literature review is warranted, however, given the complexity of LM morphology and the inconsistency of anatomical descriptions in the literature.

Methods

Scoping review of studies on LM morphology including major anatomy atlases. All relevant studies were searched in PubMed (Medline) and EMBASE until June 2019. Anatomy atlases were retrieved from multiple university libraries and online. All studies and atlases were screened for the following LM parameters: location, imaging methods, spine levels, muscle trajectory, muscle thickness, cross-sectional area, and diameter. The quality of the studies and atlases was also assessed using a five-item evaluation system.

Results

In all, 303 studies and 19 anatomy atlases were included in this review. In most studies, LM morphology was determined by MRI, ultrasound imaging, or drawings – particularly for levels L4–S1. In 153 studies, LM is described as a superficial muscle only, in 72 studies as a deep muscle only, and in 35 studies as both superficial and deep. Anatomy atlases predominantly depict LM as a deep muscle covered by the erector spinae and thoracolumbar fascia. About 42% of the studies had high quality scores, with 39% having moderate scores and 19% having low scores. The quality of figures in anatomy atlases was ranked as high in one atlas, moderate in 15 atlases, and low in 3 atlases.

Discussion

Anatomical studies of LM exhibit inconsistent findings, describing its location as superficial (50%), deep (25%), or both (12%). This is in sharp contrast to anatomy atlases, which depict LM predominantly as deep muscle. Within the limitations of the self-developed quality-assessment tool, high-quality scores were identified in a majority of studies (42%), but in only one anatomy atlas.

Conclusions

We identified a lack of standardization in the depiction and description of LM morphology. This could affect the precise understanding of its role in background and therapy in LBP patients. Standardization of research methodology on LM morphology is recommended. Anatomy atlases should be updated on LM morphology.

The Effect of Additional External Resistance on Inter-Set Changes in Abdominal Muscle Thickness during Bridging Exercise

Bridging exercises with abdominal hollowing are often used as a regimen for improving spinal stability. Lately, this type of training has become very popular among elite athletes, creating a need for more demanding exercises. The purpose of this study was to investigate whether the use of additional external resistance is beneficial for abdominal muscle recruitment during bridge exercise. Tissue movement of the transversus abdominis (TrA) and the rectus abdominis (RA) was recorded with the use of two synchronized ultrasonic devices, in 20 healthy college students. From the hook-lying position participants were examined in eight different exercise conditions: a) rest, b) abdominal drawing-in maneuver (ADIM), c) bridge, d) bridge- ADIM, e) bridge with 10KG, f) bridge- ADIM with 10KG, g) bridge with 20KG and h) bridge-ADIM with 20KG. Analysis of variance (ANOVA) showed a statistically significant increase in TrA thickness when performing the bridge exercise combined with ADIM compared to rest mode (p < .05). RA thickness decreased when the ADIM was performed, compared to rest (p < 0.05). No significant difference in TrA and RA thickness when exercising with and without external resistance was observed (p > 0.05). The main outcome of this study was that external loading provided some extra level of difficulty, yet it was not beneficial for abdominal muscle recruitment, when performing a supine bridge exercise.

Home-based exercise therapy for treating non-specific chronic low back pain

SUMMARY OBJECTIVE To evaluate pain, functional capacity, and quality of life of patients with non-specific chronic low back pain, after home-based exercise therapy with different kinds of supervision. METHOD Thirty individuals of both gender, between 18 and 65 years old, performed the proposed exercises three times a week, for eight weeks. Group A (N = 17) performed the exercises after a single supervised session. Group B (N = 13) was supervised once a week at the rehabilitation center. Both groups received a booklet with instructions, and questionnaires to evaluate pain, functional capacity and quality of life; during the initial evaluation, after four and eight weeks. RESULTS There was an improvement in pain and functional capacity between the initial evaluation and week 4, and the initial evaluation and week 8 in both groups (p <0.05). In the quality of life evaluation, the criteria for pain, functional capacity, and physical aspects had significant improvement after 8 weeks (p <0.05). There was no difference when comparing groups A and B (p >0,05). CONCLUSION Home-based exercise therapy, when performed in a period of eight weeks, using the booklet, was effective for improving level of pain, functional capacity, and quality of life in patients with non-specific chronic low back pain. The weekly supervision did not significantly influence the final outcome between the groups.

Effect of Core Training on Trunk Flexor Musculature in Male Soccer Players

The present study aimed to elucidate the effect of core training on trunk flexor musculature in athletes. Twenty-eight collegiate male soccer players were randomly assigned to three groups: a training group that performed core exercises with wheeled platforms (WP), a training group that performed body mass-based core exercise (BME), and a control group that did not perform core exercise training (CON). WP and BME trained twice a week for 10 weeks. The WP performed 8–14 exercises with wheeled platforms. BME conducted four core exercises to failure. Before and after the intervention, trunk segment lean body mass (LBM) was measured using a whole-body dual-energy X-ray absorptiometry scanner. Muscle thicknesses (MTs) of the rectus abdominis (RA), external oblique, internal oblique (IO), and transverse abdominis were determined with an ultrasound apparatus. No significant changes for any measured variables were found in CON. In both training groups, the trunk segment LBM was significantly increased through the intervention. While MT for IO significantly increased in the two training groups, significant increases in MT for RA were found in only WP. For collegiate soccer players, the core training programs adopted here can be effective in increasing trunk segment LBM, but the effectiveness on the trunk flexor muscularity differs between the two training modalities.

Improvements in tissue blood flow and lumbopelvic stability after lumbopelvic core stabilization training in patients with chronic non-specific low back pain

[Purpose] This study investigated the effects of lumbopelvic stabilization training on tissue blood flow changes in the lumbopelvic region and lumbopelvic stability compared to placebo treatment and controlled intervention among patients with chronic non-specific low back pain. [Subjects and Methods] A total of 25 participants (7 males, 18 females; mean age, 33.3 ± 14.4 years) participated in this within-subject, repeated-measures, double-blind, placebo-controlled comparison trial. The participants randomly underwent three types of interventions that included lumbopelvic stabilization training, placebo treatment, and controlled intervention with 48 hours between sessions. Lumbopelvic stability and tissue blood flow were measured using a pressure biofeedback device and a laser Doppler flow meter before and after the interventions. [Results] The repeated-measures analysis of variance results demonstrated a significant increase in tissue blood flow over the lumbopelvic region tissues for post- versus pre-lumbopelvic stabilization training and compared to placebo and control interventions. A significant increase in lumbopelvic stability before and after lumbopelvic stabilization training was noted, as well as upon comparison to placebo and control interventions. [Conclusion] The current study supports an increase in tissue blood flow in the lumbopelvic region and improved lumbopelvic stability after core training among patients with chronic non-specific low back pain.