Inspiratory Muscle Training in Rehabilitation of Low Back Pain: A Randomized Controlled Trial

Respiratory Muscle Training in Para-Athletes: A Systematic Review on the Training Protocols and Effects on Reported Outcomes

CONTEXT AND OBJECTIVES

Respiratory muscle training (RMT) is considered an effective tool to improve cardiorespiratory limitations in athletes. The goals of this systematic review were to explore the role of RMT and its implementation within sport rehabilitation programs in para-athletes.

EVIDENCE ACQUISITION

Several databases were searched until January 2024. Eligible studies were independently reviewed by 2 reviewers. Quality assessment was made using the PEDro scale and version 2 of the Cochrane Risk-of-Bias Tool for Randomized Trials. Eight studies (a total of 108 participants) were selected for the analysis.

EVIDENCE SYNTHESIS

Five studies preferred using resistive loading, while 2 studies used normocapnic hyperpnea, and 1 study used threshold inspiratory muscle training. Respiratory functions (respiratory muscle strength and endurance, spirometry measures) and exercise performance were assessed as the main outcomes. Significant increases in respiratory muscle strength were reported in 5 studies. Two studies observed improvement in respiratory muscle endurance and 3 studies reported increased exercise capacity.

CONCLUSIONS

This review suggests that although RMT can enhance respiratory muscle strength and endurance, it should not be considered the primary method for boosting the exercise performance of para-athletes. Additional research is necessary to explore the impact of various RMT techniques on different outcomes from the perspective of sport rehabilitation in para-athletes.

Effectiveness of simultaneous bilateral visual diaphragm biofeedback under low back pain: influence of age and sex

Introduction: The aim of the present study was to determine the effectiveness of simultaneous bilateral visual diaphragm biofeedback (BFB) from ultrasonography in conjunction with inspiratory muscle training (IMT) on diaphragmatic thickness during normal breathing and respiratory and clinical outcomes in patients with non-specific low back pain (NSLBP) and determine the influence of age and sex. Methods: A single-blind randomized clinical trial was carried out (NCT04582812). A total sample of 96 patients with NSLBP was recruited and randomized by sex-based stratification into IMT (n = 48) and BFB + IMT (n = 48) interventions over 8 weeks. Bilateral diaphragmatic thickness at maximum inspiration (Tins) and expiration (Texp), respiratory pressures, lung function, pain intensity, bilateral pressure pain threshold (PPT), disability, and quality of life were measured at baseline and after 8 weeks. Results: The BFB + IMT group showed significant differences (p < 0.05) with increased left hemidiaphragm thickness at Tins and Tins-exp (d = 0.38-053), and right and left PPT (d = 0.71-0.74) versus the IMT group. The interaction with sex was statistically significant (p = 0.007; F(1,81) = 7.756; ηp 2 = 0.087) and higher left hemidiaphragm thickness at Tins was predicted by the BFB + IMT group (R 2 = 0.099; β = 0.050; F(1,82) = 8.997; p = 0.004) and male sex (R 2 = 0.079; β = 0.045; F(1,81) = 7.756;p = 0.007). Furthermore, greater left hemidiaphragm thickness at Tins-exp was predicted by younger age (R 2 = 0.052; β = -0.001; F(1,82) = 4.540; p = 0.036). Discussion: The simultaneous bilateral visual diaphragm biofeedback by ultrasonography in conjunction with IMT was effective in both increasing the left diaphragmatic thickness during inspiration, which was positively influenced and predicted by male sex and younger age, and increasing the bilateral PPT of the paraspinal muscles in patients with NSLBP.

Effects of Respiratory Muscle Training on Functional Ability, Pain-Related Outcomes, and Respiratory Function in Individuals with Low Back Pain: Systematic Review and Meta-Analysis

Objectives: The aim of this meta-analysis was to determine the effects of respiratory muscle training (RMT) on functional ability, pain-related outcomes, and respiratory function in individuals with sub-acute and chronic low back pain (LBP). Methods: The study selection was as follows: (participants) adult individuals with >4 weeks of LBP; (intervention) RMT; (comparison) any comparison RMT (inspiratory or expiratory or mixed) versus control; (outcomes) postural control, lumbar disability, pain-related outcomes, pain-related fear-avoidance beliefs, respiratory muscle function, and pulmonary function; and (study design) randomized controlled trials. Results: 11 studies were included in the meta-analysis showing that RMT produces a statistically significant increase in postural control (mean difference (MD) = 21.71 [12.22; 31.21]; decrease in lumbar disability (standardized mean difference (SMD) = 0.55 [0.001; 1.09]); decrease in lumbar pain intensity (SMD = 0.77 [0.15; 1.38]; increase in expiratory muscle strength (MD = 8.05 [5.34; 10.76]); and increase in forced vital capacity (FVC) (MD = 0.30 [0.03; 0.58]) compared with a control group. However, RMT does not produce an increase in inspiratory muscle strength (MD = 18.36 [-1.61; 38.34]) and in forced expiratory volume at the first second (FEV1) (MD = 0.36 [-0.02; 0.75]; and in the FEV1/FVC ratio (MD = 1.55 [-5.87; 8.96]) compared with the control group. Conclusions: RMT could improve expiratory muscle strength and FVC, with a moderate quality of evidence, whereas a low quality of evidence suggests that RMT could improve postural control, lumbar disability, and pain intensity in individuals with sub-acute and chronic LBP. However, more studies of high methodological quality are needed to strengthen the results of this meta-analysis.

The Efficiency of Respiratory Exercises in Rehabilitation of Low Back Pain: A Systematic Review and Meta-Analysis

BACKGROUND

Low back pain (LBP) is a common musculoskeletal disorder, and respiratory exercise is considered a nonsurgical management method. Therefore, this systematic review and meta-analysis aims to estimate the results of randomized controlled trials on the effect of respiratory training in reducing LBP and its dose relationship.

METHODS

The present study was conducted from January 2020 to January 2022, following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines (2020). Relevant studies were searched in multiple databases including PubMed, Web of Science, the Cochrane Library, EBSCO, Scopus, ScienceDirect, Wan Fang and China Knowledge Network, ClinicalTrials.gov, and Google Scholar, using a combination of MeSH/Emtree terms and free-text words. The heterogeneity of the studies was assessed using the I2 statistic.

RESULTS

A total of 14 publications were included in the meta-analysis, with a total sample size of 698 individuals, aged 60-80 years. Respiratory exercise was effective in relieving LBP (standardized mean difference = -0.87, P < .00001) and improving physical disability (standardized mean difference = -0.79, P < .00001). The type of breathing and the total duration of breathing exercises were found to be the source of heterogeneity in this study by subgroup analysis. Subgroup analysis revealed that the most significant effect sizes of breathing resistance exercise to reduce LBP and the most significant effect sizes of breathing relaxation techniques to alleviate physical disability were performed 3 to 5 times per week and period >4 weeks. Respiratory exercise reducing LBP and improving functional disability was most effective when the total duration of the intervention was >500 minutes. Funnel plots showed that the results of the 2 overall studies were reliable without publication bias.

CONCLUSIONS

Respiratory exercise can effectively reduce LBP and improve physical disability. Therefore, these exercises can be regarded as a part of a LBP management plan. We recommend an exercise program with 30 to 50 minutes, 3 to 5 times per week, and >4 weeks of breathing resistance exercise program as the most effective for treating LBP.

Effects of breathing exercises on chronic low back pain: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

A range of studies concerning the effects of breathing exercises on chronic low back pain (CLBP) have been proven inconclusive.

OBJECTIVE

The study aimed to evaluate the effectiveness of breathing exercises for the treatment of CLBP.

METHODS

We considered randomized controlled trials in English or Chinese that used breathing exercises for the treatment of CLBP. An electronic search was performed in the MEDLINE, EMBASE, Web of Science, Cochrane Library, CNKI, Wan Fang, and CBM databases for articles published up to November 2022. Two reviewers independently screened the articles, assessed the risk of bias using the Cochrane risk of bias tool, and extracted the data. The outcomes included pain, lumbar function and pulmonary function post-intervention.

RESULTS

A total of thirteen studies (n= 677) satisfied the inclusion criteria. The meta-analysis results demonstrated a significant effect of breathing exercises on the Visual Analog Scale (VAS) score (SMD =-0.84, 95% CI: -1.24 to -0.45, P< 0.0001), the Oswestry Disability Index (ODI) score (SMD =-0.74, 95% CI: -0.95 to -0.54, P< 0.00001), Forced Vital Capacity (FVC) score (MD = 0.24, 95% CI: 0.10 to 0.37, P= 0.0006), Forced Expiratory Volume in 1 second /Forced Vital Capacity (FEV1/FVC) (MD = 1.90, 95% CI: 0.73 to 3.07, P= 0.001), although there was no significant difference between the breathing exercises and control interventions for Forced Expiratory Volume in the first second (FEV1) score (MD = 0.22, 95% CI = [0.00, 0.43], P= 0.05), and Maximal Voluntary Ventilation (MVV) score (MD = 8.22, 95% CI = [-4.02, 20.45], P= 0.19).

CONCLUSION

Breathing exercises can reduce pain, assist people with lumbar disabilities, and improve pulmonary function, and could be considered as a potential alternative treatment for CLBP.

Effects of breathing exercises on low back pain in clinical: A systematic review and meta-analysis

OBJECTIVE

This study aims to systematically evaluate the effect of breathing exercises on the low back pain (LBP).

METHODS

The studies of relevant randomized controlled trials (RCTs) testing the effect of breathing exercises on LBP were selected after strict screening from the establishment of PubMed, EMBASE, Cochrane Library, Web of Science, CBM, and CNKI databases until September 2022. The studies included were then independently assessed for risk bias by two investigators. The PRISMA 2020 statement was followed in this study.

RESULTS

11 RCTs involving 383 patients were included in this analysis. Results showed that the effective rate of LBP patients after breathing exercises was significantly higher than those in the control group, and the VAS (Visual Analogue Score) and ODI (Oswestry Disability Index) scores of LBP patients were significantly lower than those in the control group [VAS: MD = -0.50, 95% CI (-0.88, -0.11), I2 = 76%, p = 0.0009; ODI: MD = -2.46, 95% CI (-3.41, -1.52), I2 = 20%, p = 0.28]. The results of subgroup showed that the duration of treatment had little effect on the effect of breathing exercises, and breathing exercises alone could also have a positive effect on LBP. However, there were methodological limitations in the included studies, future studies should ensure blinded outcome assessors and full reporting to reduce bias risks. Because this review is a study of breathing exercises as an intervention without any adverse events, all studies did not involve safety assessments.

CONCLUSIONS

The results indicated that breathing exercises have a positive effect on alleviating LBP, but due to the lack of methodological rigor and some limitations of the included studies, more critical RCTs are still needed in the future to verify the precision of this conclusion. The protocol was registered in PROSPERO (No. CRD42022345561).

Diaphragm and core stabilization exercises in low back pain: A narrative review

INTRODUCTION

Core stabilization is a vital concept in clinical rehabilitation (including low back pain rehabilitation) and competitive athletic training. The core comprises of a complex network of hip, trunk and neck muscles including the diaphragm.

AIMS

The paper aims to discuss the role of the diaphragm in core stability, summarize current evidence and put forth ideal core training strategies involving the diaphragm.

METHOD

Narrative review RESULTS: The diaphragm has a dual role of respiration and postural control. Evidence suggests that current core stability exercises for low back pain are superior than minimal or no treatment, however, no more beneficial than general exercises and/or manual therapy. There appears to be a higher focus on the transversus abdominis and multifidi muscles and minimal attention to the diaphragm. We propose that any form of core stabilization exercises for low back pain rehabilitation should consider the diaphragm. Core stabilization program could commence with facilitation of normal breathing patterns and progressive systematic restoration of the postural control role of the diaphragm muscle.

CONCLUSION

The role of the diaphragm is often overlooked in both research and practice. Attention to the diaphragm may improve the effectiveness of core stability exercise in low back pain rehabilitation.

Impact of Indoor Air Quality and Breathing on Back and Neck Pain: A Systematic Review

Back pain and neck pain are important public health concerns and are among the most common and disabling conditions globally. However, the relationships among indoor air quality (IAQ), breathing parameters (pulmonary function, respiratory disorders), and back pain and neck pain have not been adequately assessed. The purpose of this study was to systematically review the literature about the impact of IAQ and breathing parameters on back pain and neck pain (PROSPERO ID: CRD42022380515). CINAHL, EMBASE, PEDRo, and PubMed databases were searched through January 19, 2023. Inclusion criteria for study eligibility were observational studies (except case reports) or randomized controlled trials (RCTs), published in peer-reviewed journals in the English language, human research, original research, examined the relationships between IAQ, or breathing parameters with back pain or neck pain. Review procedures were conducted and reported according to PRISMA recommendations. Empirical evidence statements were developed for observational studies, and grades of evidence statements were developed for RCTs. Sixty-seven eligible studies were found (54 observational studies and 13 RCTs) that enrolled 345,832 participants. None of the studies assessed the combined impact of IAQ and breathing parameters on back pain or neck pain. No level 1 studies were found, which precludes making strong statements about causality and strong recommendations about the efficacy of IAQ and breathing exercise interventions for reducing pain and disability related to back pain and neck pain. Evidence indicates that poor IAQ and respiratory disorders are related to an increased risk of back pain and neck pain. Conflicting evidence exists about the association between pulmonary function with back pain and neck pain. Evidence for breathing exercise interventions was mixed with numerous limitations. This review provides preliminary evidence on the relationships of IAQ and breathing parameters with back pain and neck pain, which can be used to guide future research and clinical implementation efforts. Assuming positive findings in subsequent research, a wide range of stakeholders involved with this complex human-building-environment interface can be equipped to address IAQ and breathing parameters, along with other established risk factors to help those suffering from back pain and neck pain.

Diaphragmatic breathing exercises in recovery from fatigue-induced changes in spinal mobility and postural stability: a study protocol

Prolonged periods of sitting at work can increase trunk muscle fatigue from the continuous contraction of deep trunk muscles. Insufficient activity of these muscles can decrease muscular support to the spine and increases stress on its passive structures. This can lead to reduced spinal mobility and impaired postural stability. It may also stimulate nociceptor activity leading to pain. However, frequently used recovery modalities such as muscle strengthening and stretching exercises, can be time-consuming, impractical, and difficult to implement in the workplace. Diaphragmatic breathing exercises, which increase the activity of the deep trunk muscles by raising intra-abdominal pressure, seem to be a suitable alternative. However, little is known as to what extent diaphragmatic breathing exercises contribute to the reduction of fatigue induced by prolonged sitting. This paper presents a study protocol that aims to investigate the acute effect of diaphragmatic breathing exercises on recovery of fatigue-induced changes in spinal mobility and postural stability in sedentary middle-aged adults at risk of developing non-specific low back pain. Twenty sedentary adults aged between 25 and 44 years will perform Abt's fatigue protocol, followed by 1) active recovery using diaphragmatic breathing exercises and 2) passive recovery in the form of lying on the bed, respectively. There will be 1 week of rest in-between. Pre-fatigue, post-fatigue, and after the active and passive recovery, spinal mobility and postural stability will be evaluated using the spinal mouse device and a posturography system, respectively. The electromyography will be used to determine the muscle-fatigue conditions. We hypothesize that active recovery in a form of diaphragmatic breathing exercises would be more effective in restoring spinal mobility and postural stability followed by the fatigue of back and hamstring muscles compared to passive recovery in sedentary adults. Increasing core and respiratory muscle strength via these exercises could be beneficial for overall mobility and stability of the spine. Reducing compressive stress on the passive structures of the spine may be also beneficial for lowering low back pain. Therefore, we believe that diaphragmatic breathing exercises have the possibility to be incorporated into the workplace and contribute to better back health in sedentary middle-aged adults. Clinical Trial Registration: [https://www.irct.ir/trial/67015], identifier [IRCT20221126056606N1].

Exploring the role of respiratory intervention as an effective adjunct tool in the management of chronic low back pain: A scoping systematic review

BACKGROUND

Individuals with chronic low back pain (CLBP) are usually prescribed manual therapy and exercise programs. Respiratory exercise interventions are also recommended by some researchers for CLBP. However, the evidence for the relative effectiveness of these treatments is limited, and the question of which sort of intervention is most suited remains unanswered.

OBJECTIVE

This systematic review aims to evaluate the effectiveness of respiratory interventions in CLBP.

METHODS

A systematic search was performed using databases: PubMed, Web of Science, PEDro, Cochrane Library, and Science Direct. The review was registered in PROSPERO (CRD42021233739).

RESULTS

Seven studies met the inclusion criteria. Out of these, one was of poor, three were of fair, and three were of good qualities. A total of 293 subjects were included in seven studies, the mean age of subjects ranged from 21 to 53 years. The largest effect size was reported for pain (d = 1.5) and maximum inspiratory pressure (d = 1.38). No detrimental effects were reported for any of the intervention programs.

CONCLUSIONS

Since most of the research has been done on pain and MIP, and both of these parameters have revealed significant changes with large effect size, therefore it can be concluded that respiratory interventions improve pain and MIP in CLBP. Owing to the limited number of studies available, a definitive outcome could not be documented for other parameters. Thus, further research is needed to provide a more robust piece of evidence and understanding.

Effectiveness of Ultrasonography Visual Biofeedback of the Diaphragm in Conjunction with Inspiratory Muscle Training on Muscle Thickness, Respiratory Pressures, Pain, Disability, Quality of Life and Pulmonary Function in Athletes with Non-Specific Low Back Pain: A Randomized Clinical Trial

Diaphragmatic weakness and thickness reduction have been detected in athletes with lumbopelvic pain (LPP). Strength training of inspiratory muscles may be necessary for athletes with LPP. Inspiratory muscle training (IMT) and visual biofeedback by rehabilitative ultrasound imaging (RUSI) have been proposed as possible interventions. Here, we determine the effectiveness of visual biofeedback by RUSI with a proposed novel thoracic orthotic device to facilitate diaphragmatic contraction in conjunction with high-intensity IMT in athletes with non-specific LPP. A single-blinded, parallel-group, randomized clinical trial was performed (NCT04097873). Of 86 participants assessed for eligibility, 64 athletes with non-specific LPP (39 males and 25 females; mean age, 33.15 ± 7.79 years) were recruited, randomized, analyzed and received diaphragm visual biofeedback by RUSI in conjunction with high-intensity IMT (RUSI+IMT; n = 32) or isolated high-intensity IMT (IMT; n = 32) interventions for 8 weeks. Diaphragmatic thickness during normal breathing, maximum respiratory pressures, pain intensity, pressure pain threshold on lumbar musculature, disability by the Roland−Morris questionnaire, quality of life by the SF-12 questionnaire and spirometry respiratory parameters were assessed at baseline and after the 8-week intervention. There were significant differences (p = 0.015), within a medium effect size (Cohen’s d = 0.62) for the forced expiratory volume in 1-s (FEV1), which was increased in the RUSI+IMT intervention group relative to the IMT alone group. Adverse effects were not observed. The rest of the outcomes did not show significant differences (p > 0.05). Diaphragm visual biofeedback by RUSI with the proposed novel thoracic orthotic device in conjunction with high-intensity IMT improved lung function by increasing FEV1 in athletes with non-specific LPP.

Is there a role of pulmonary rehabilitation in extrapulmonary diseases frequently encountered in the practice of physical medicine and rehabilitation?

There is a group of diseases such as low back pain, osteoporosis, fibromyalgia and obesity for which pulmonary rehabilitation can be applied. Although these diseases do not directly impact the lungs, respiratory dysfunction occurs through various mechanisms during the disease process and complicates the underlying primary disease. Respiratory dysfunction and spirometric abnormalities have been observed from the early stages of these diseases, even without obvious signs and symptoms. These patients should be carefully evaluated for pulmonary problems as a sedentary lifestyle may hide the presence of respiratory symptoms. Once pulmonary problems have been detected, pulmonary rehabilitation should be added to the routine treatment of the primary disease.

Effects of a new respiratory muscle training device in community-dwelling elderly men: an open-label, randomized, non-inferiority trial

Background

Respiratory muscle training (RMT) has various clinical benefits in older adults; however, the low adherence to training remains a challenging issue. The present study aimed to confirm the efficacy of a new device that combines inspiratory muscle training and a positive expiratory pressure (IMT/PEP) compared to that of a Threshold IMT device (Philips Respironics Inc), and to determine whether home-based training differed from rehabilitation center training.

Methods

This four-arm, multicenter, parallel, non-inferiority trial randomized 80 active community-dwelling older men (mean age = 72.93 ± 5.02 years) to center-based groups (new IMT/PEP device or Threshold IMT device; 16 supervised sessions) or home-based groups (new IMT/PEP device or Threshold IMT device; 2 supervised sessions and individual sessions). Participants in all groups performed RMT twice a day for 8 weeks. Assessments were performed at baseline and post-training. The primary outcomes were maximum inspiratory pressure and maximal expiratory pressure. The secondary outcomes included forced vital capacity and forced expiratory volume in the first second, peak cough flow, diaphragm thickness, VO₂ peak, the International Physical Activity Questionnaire score, electromyographic activities of the sternocleidomastoid muscle, and skeletal muscle mass and phase angle as measured by bioimpedance analysis. In addition, rates of adherence to each protocol were also compared.

Results

Among all groups, the maximal inspiratory pressure was improved post-training, while the maximal expiratory pressure showed improvement only in the IMT/PEP groups. The overall non-inferiority of the IMT/PEP device was thus validated. A statistically significant improvement in diaphragm thickness was found. However, no consistent improvement was shown in other secondary outcomes. No significant difference in training adherence rate between protocols was observed (mean adherence rate of 91–99%).

Conclusion

Compared to the Threshold IMT, the new IMT/PEP device did not result in a significant difference in maximal inspiratory pressure but did improve maximal expiratory pressure in older men. The IMT/PEP device’s improved usability, which is associated with exercise adherence, provided distinct advantages in this cohort. If proper education is first provided, home-based RMT alone may provide sufficient effects in older individuals.

Trial registration

This trial was registered in the database cris.nih.go.kr (registration number KCT0003901) on 10/05/2019.