Concurrent Validity and Reliability of Manual Versus Specific Device Transcostal Measurements for Breathing Diaphragm Thickness by Ultrasonography in Lumbopelvic Pain 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.

A Secondary Analysis of Gender Respiratory Features for Ultrasonography Bilateral Diaphragm Thickness, Respiratory Pressures, and Pulmonary Function in Low Back Pain

The aim of the present study was to determine the gender respiratory differences of bilateral diaphragm thickness, respiratory pressures, and pulmonary function in patients with low back pain (LBP). A sample of 90 participants with nonspecific LBP was recruited and matched paired by sex (45 women and 45 men). Respiratory outcomes included bilateral diaphragm thickness by ultrasonography, respiratory muscle strength by maximum inspiratory (MIP) and expiratory (MEP) pressures, and pulmonary function by forced expiratory volume during 1 s (FEV1), forced vital capacity (FVC) and FEV1/FVC spirometry parameters. The comparison of respiratory outcomes presented significant differences (p < 0.001), with a large effect size (d = 1.26-1.58) showing means differences (95% CI) for MIP of -32.26 (-42.99, -21.53) cm H2O, MEP of -50.66 (-64.08, -37.25) cm H2O, FEV1 of -0.92 (-1.18, -0.65) L, and FVC of -1.00 (-1.32, -0.69) L, with lower values for females versus males. Gender-based respiratory differences were presented for maximum respiratory pressures and pulmonary function in patients with nonspecific LBP. Women presented greater inspiratory and expiratory muscle weakness as well as worse lung function, although these differences were not linked to diaphragm thickness during normal breathing.

Reliability and validity of ultrasonography in evaluating the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals: a systematic review

OBJECTIVE

To summarize the reliability and validity of ultrasonography in evaluating the stiffness, excursion, stiffness, or strain rate of diaphragm, intercostals and abdominal muscles in healthy or non-hospitalized individuals.

LITERATURE SEARCH

PubMed, Embase, SPORTDiscus, CINAHL and Cochrane Library were searched from inception to May 30, 2022.

STUDY SELECTION CRITERIA

Case-control, cross-sectional, and longitudinal studies were included if they investigated the reliability or validity of various ultrasonography technologies (e.g., brightness-mode, motion-mode, shear wave elastography) in measuring the thickness, excursion, stiffness, or strain rate of any respiratory muscles.

DATA SYNTHESIS

Relevant data were summarized based on healthy and different patient populations. The methodological quality by different checklist depending on study design. The quality of evidence of each psychometric property was graded by the Grading of Recommendations, Assessment, Development and Evaluations, respectively.

RESULTS

This review included 24 studies with 787 healthy or non-hospitalized individuals (e.g., lower back pain (LBP), adolescent idiopathic scoliosis (AIS), and chronic obstructive pulmonary disease (COPD)). Both inspiratory (diaphragm and intercostal muscles) and expiratory muscles (abdominal muscles) were investigated. Moderate-quality evidence supported sufficient (intra-class correlation coefficient > 0.7) within-day intra-rater reliability of B-mode ultrasonography in measuring right diaphragmatic thickness among people with LBP, sufficient between-day intra-rater reliability of M-mode ultrasonography in measuring right diaphragmatic excursion in non-hospitalized individuals. The quality of evidence for all other measurement properties in various populations was low or very low. High-quality evidence supported sufficient positive correlations between diaphragm excursion and forced expiratory volume in the first second or forced vital capacity (r >  = 0.3) in healthy individuals.

CONCLUSIONS

Despite the reported sufficient reliability and validity of using ultrasonography to assess the thickness, excursion, stiffness, and strain rate of respiratory muscles in non-hospitalized individuals, further large-scale studies are warranted to improve the quality of evidence regarding using ultrasonography for these measurements in clinical practice. Researchers should establish their own reliability before using various types of ultrasonography to evaluate respiratory muscle functions.

TRIAL REGISTRATION

PROSPERO NO. CRD42022322945.

Ultrasonographic reliability and repeatability of simultaneous bilateral assessment of diaphragm muscle thickness during normal breathing

Background

The diaphragm is considered the main muscle involved in breathing and also linked to trunk stabilization functions. Up to date, rehabilitative ultrasound imaging (RUSI) has been the most used technique to evaluate unilaterally the transcostal diaphragm thickness. Nevertheless, the inspiratory activity of both hemi-diaphragms is bilaterally performed at the same time, and its simultaneous evaluation with a thoracic orthosis could improve its assessment as well as its re-education with visual biofeedback of both hemi-diaphragms at the same time. The purpose was to evaluate the reliability and repeatability of simultaneous thickness measurements of both hemi-diaphragms bilaterally during normal breathing using a thoracic orthosis that allowed bilateral fixation of both right and left ultrasound probes.

Methods

The study was conducted in 46 healthy subjects, whose diaphragm thickness was measured bilaterally and simultaneously in the anterior axillary line during relaxed breathing with a designed thoracic orthosis and 2 ultrasound tools. Intra-examiner (same examiner), inter-examiner (2 examiners), intra-session (1 hour) and inter-session (1 week) reliability and repeatability between each pair of measurements of diaphragm muscle thickness were analyzed during normal breathing.

Results

Reliability and repeatability for intra-session evaluations using the thoracic orthosis were excellent to evaluate simultaneous thickness of both hemi-diaphragms by bilateral probes fixation (intraclass correlation coefficient =0.919-0.997; standard error of measurement =0.002-0.007 cm; minimum detectable change =0.006-0.020 cm), without systematic errors (P>0.05) between each pair of measurements. Nevertheless, inter-session evaluations varied from good to excellent using the bilateral probes fixation (intraclass correlation coefficient =0.614-0.984; standard error of measurement =0.006-0.028 cm; minimum detectable change =0.017-0.079 cm), although some systematic errors were presented (P<0.05).

Conclusions

Good to excellent reliability and repeatability was shown for simultaneous thickness measurements of both hemi-diaphragms bilaterally during normal breathing. Despite systematic errors were presented for some inter-examiner assessments, the use of the thoracic orthosis that allowed bilateral fixation of ultrasound probes could be recommended for simultaneous hemi-diaphragms breathing re-education by visual biofeedback.

Ultrasonography Comparison of Diaphragm Morphological Structure and Function in Young and Middle-Aged Subjects with and without Non-Specific Chronic Low Back Pain: A Case-Control Study

Background

It is reported that impaired postural control in patients with non-specific chronic low back pain (NCLBP) was associated with "core" trunk muscle incoordination. However, as the diaphragm is an important component of the "core" deep trunk muscle group, we still know little about the potential relationship between diaphragm dysfunction and NCLBP.

Objectives

This case-control study is intended to investigate the changes of diaphragm morphological structure and function in young and middle-aged subjects with and without NCLBP by ultrasound evaluation and its possible validity in predicating the occurrence of NCLBP.

Methods

31 subjects with NCLBP (NCLBP group) and 32 matched healthy controls (HC group) were enrolled in this study. The diaphragm thickness at the end of inspiration (T ^ins) or expiration (T ^exp) during deep breathing was measured through B-mode ultrasound, and the diaphragm excursion (T ^exc) was estimated at deep breathing through M-mode ultrasound. The diaphragm thickness change rate (T ^rate) was calculated by the formula: T ^rate=(T ^ins - T ^exp)/T ^exp × 100%.

Results

Compared with the HC group, the NCLBP group had a significant smaller degree of T^ins (t = -3.90, P < 0.001), T ^exp (Z = -2.79, P=0.005), and T ^rate (t = -2.03, P=0.047). However, there was no statistical difference in T ^exc between the two groups (t = -1.42, P=0.161). The binary logistic regression analysis indicated that T ^rate (OR = 16.038, P=0.014) and T ^exp (OR = 7.714, P=0.004) were potential risk factors for the occurrence of NCLBP.

Conclusions

The diaphragm morphological structure and function were changed in young and middle-aged subjects with NCLBP, while the diaphragm thickness change rate (T ^rate) and diaphragm thickness at the end of expiration (T ^exp) may be conductive to the occurrence of NCLBP. Furthermore, these findings may suggest that abnormal diaphragm reeducation is necessary for the rehabilitation of patients with NCLBP.

Intra-Rater Reliability of Shear Wave Elastography for the Quantification of Respiratory Muscles in Adolescent Athletes

The aim of this study was to assess the intra-rater reliability and agreement of diaphragm and intercostal muscle elasticity and thickness during tidal breathing. The diaphragm and intercostal muscle parameters were measured using shear wave elastography in adolescent athletes. To calculate intra-rater reliability, intraclass correlation coefficient (ICC) and Bland-Altman statistics were used. The reliability/agreement for one-day both muscle measurements (regardless of probe orientation) were at least moderate. During the seven-day interval between measurements, the reliability of a single measurement depended on the measured parameter, transducer orientation, respiratory phase, and muscle. Excellent reliability was found for diaphragm shear modulus at the peak of tidal expiration in transverse probe position (ICC_3.1 = 0.91-0.96; ICC₃.₂ = 0.95), and from poor to excellent reliability for the intercostal muscle thickness at the peak of tidal inspiration with the longitudinal probe position (ICC_3.1 = 0.26-0.95; ICC₃.₂ = 0.15). The overall reliability/agreement of the analysed data was higher for the diaphragm measurements (than the intercostal muscles) regardless of the respiratory phase and probe position. It is difficult to identify a more appropriate probe position to examine these muscles. The shear modulus/thickness of the diaphragm and intercostal muscles demonstrated good reliability/agreement so this appears to be a promising technique for their examination in athletes.

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.