Background:Multimodal exercise programs do not specifically target lumbar paraspinal musculature, but incorporate aspects of different exercises to have an overall benefit. Objective:To investigate the effect of a multimodal exercise program on paraspinal muscle volume and composition, and patient outcomes in individuals with chronic low back pain (CLBP). Methods:Thirty-four participants with CLBP either completed a 14-week high-intensity training program (n = 8) including cardiorespiratory and resistance exercises 3 sessions per week or were waitlisted (n = 26). Participants underwent magnetic resonance imaging at baseline and post-intervention to assess paraspinal muscle volume (cm3) and fatty infiltration (% FI) at L3-L4, L4-L5, and L5-S1. Pain, disability, quality of life, pain-related fear (catastrophizing and Kinesiophobia), and anxiety were assessed via validated self-reported questionnaires. Results:Mixed-design ANOVA revealed no significant time × group interactions for paraspinal muscle volume and %FI. An exploratory analysis revealed a significant increase in multifidus %FI in the control group at L3-L4, L4-L5, and L5-S1, with a concomitant increase in multifidus volume at L3-L4 and L5-S1. The exercise group had a significant increase in multifidus %FI and volume at L5-S1. Significant time × group interactions for pain, disability, catastrophizing and kinesiophobia, and a main effect of group in physical and mental health were found. Significant correlations were found between changes in patient-reported and functional outcomes with paraspinal muscle morphology. Conclusion:Multimodal exercise programs may help prevent LBP-related paraspinal muscle atrophy and %FI, and lead to concomitant improvements in pain, disability and pain-related fear in individuals with CLBP.

Abstract Background Muscular dysfunction of the lumbar-pelvic-hip complex is a hallmark of chronic low back pain (cLBP). This dysfunction is partly driven by muscle morphometry and composition, highlighting their importance in cLBP. Exercise-based interventions are commonly used in cLBP management; however, the extent to which different therapeutic approaches influence gluteal muscle health remains unclear. Aquatic therapy may offer a distinct therapeutic environment by reducing spinal loading while facilitating progressive muscle activation. Objectives This study aimed to (1) investigate the effects of aquatic therapy (AT) versus standard care (SC) on gluteal muscle size, intramuscular fat (IMF) and strength in patients with cLBP and (2) investigate whether positive changes in gluteal muscle health (i.e., size, composition, strength) are associated with concomitant improvements in patient-oriented outcomes. Methods This randomized controlled trial included 34 participants with moderate-to-severe cLBP. The participants were randomized to either AT (n = 18) or SC (n = 16). Both groups completed a 10-week supervised intervention program consisting of 2 sessions per week. The baseline and postintervention assessments included pelvic magnetic resonance imaging, gluteal strength testing, and patient-reported questionnaires. Changes in muscle-related and patient-oriented outcomes within and between groups were analyzed using repeated-measures analysis of covariance, with baseline disability as a covariate. Results Repeated measures analysis of covariance revealed no significant changes in gluteal muscle volume in either group. Significant decreases in IMF were observed in the gluteus maximus (-2.56 [95%CI: -4.47 to -0.64], p = 0.01) and gluteus medius (-1.00 [95%CI: -1.97 to -0.04], p = 0.04) in the AT group, with no significant changes in the SC group. Both groups demonstrated significant increases in gluteal maximus (AT:55.20 [95%CI: 31.84 to 78.55], p < 0.001; SC:41.45 [95%CI: 16.52 to 66.38], p = 0.002) and medius (AT:72.34 [95%CI: 44.62 to 100.05], p < 0.001; SC:43.91 [95%CI: 14.32 to 73.49], p = 0.005) strength. Improvements in gluteus IMF were moderately correlated with increases in physical quality of life (gluteus maximus: r=-0.33; gluteus medius: r=-0.31) and decreases in pain catastrophizing (gluteus minimus: r = 0.39). Conclusion The AT group demonstrated significant improvements in strength and IMF content, suggesting potential musculoskeletal benefits health in individuals with cLBP. Trial registration This study was registered at ClinicalTrials.gov (NCT05823857 on 10/04/2023).

BACKGROUND:Anxiety, depression, and pain-related fears are highly prevalent among individuals with chronic low back pain (CLBP). While aquatic therapy is a promising treatment modality for CLBP, its effects on psychological factors remain poorly understood. OBJECTIVE:To compare the effects of aquatic therapy (AT) versus standard care (SC) on psychological outcomes, pain, and disability in CLBP. METHODS:In this two-arm randomized controlled trial, 34 participants with CLBP were assigned to AT (n = 18) or SC (n = 16). Both groups received bi-weekly individual sessions over 10 weeks. Pain, disability, quality of life, anxiety, depression, pain catastrophizing, kinesiophobia, and sleep disturbance were assessed using the following validated questionnaires; Numerical Pain Rating Scale, Modified Oswestry Low Back Pain Disability Index, Short-Form 12 Item Survey Questionnaire, Hospital Anxiety and Depression Scale, Pain Catastrophizing Scale, Tampa Scale of Kinesiophobia and Insomnia Severity Index, respectively. RESULTS:Mixed-design analysis of covariance revealed no significant group*time interactions for any outcomes (all p > 0.05). Both groups improved significantly in pain, disability, quality of life, pain catastrophizing, and anxiety (all p < 0.05). Only AT demonstrated significant reductions in kinesiophobia (p = 0.002) and sleep disturbance (p = 0.001). CONCLUSIONS:Aquatic therapy may offer a more comfortable treatment alternative to address psychological factors associated with CLBP. CLINICAL TRIAL REGISTRATION:www.clinicaltrials.gov identifier is NCT05823857.

Introduction Exercise therapy is the most recommended treatment for chronic low back pain (LBP), with evidence supporting modest effects, likely due to the heterogeneity of patient presentations. Evidence suggests that matching individuals to the most appropriate exercise type could improve outcomes. Systematic reviews also emphasise that effective exercise interventions should be patient centred, target paraspinal muscle health and be of sufficient duration. This study addresses these gaps using a targeted care approach to identify a homogenous sample that is more likely to respond to our interventions. The inclusion of a sample with predominant nociceptive pain profile will be performed with the integration of the Pain and Disability Drivers Management Model (PDDM) and the Lumbar Spine Instability Questionnaire (LSIQ). The primary aim of this two-arm randomised controlled trial is to compare the effectiveness of motor control plus isolated lumbar extension exercises (MC+ILEX, arm 1) to free-weight resistance training (arm 2) in reducing LBP-related disability. Secondary aims include examining whether changes in multifidus composition mediate disability improvements comparing intervention effects on muscle size and quality, strength, mobility, pain, quality of life, sleep, physical activity and satisfaction; exploring baseline LSIQ scores and sex/gender as moderators of treatment response; and investigating participants’ perceptions and experiences of exercise therapy.Methods and analysis A total of 106 participants will be recruited through primary and secondary care and randomised (1:1) to receive either MC+ILEX or free-weight resistance training. Both groups will complete 48 exercise sessions over 16 weeks. The primary outcome will be disability at 16 weeks, measured by the Oswestry Disability Index. Secondary outcomes include multifidus muscle composition and size, lumbar and gluteal muscle strength, hip range of motion, pain, physical and mental function, satisfaction and recovery, health-related quality of life, sleep quality and physical activity levels. Linear mixed-effects models will be used to assess primary and secondary outcomes. Regression analyses will explore whether baseline LSIQ scores moderate treatment effects on multifidus composition and other outcomes. A subsample of participants will undergo semistructured interviews before and after the intervention to explore their illness perceptions, illness mindsets, perceptions of exercise therapy, as well as their experiences and satisfaction with the two exercise interventions. Reflexive thematic analysis will be used to analyse qualitative data.Ethics and dissemination This study received ethics approval from the Central Ethics Research Committee of the Quebec Minister of Health and Social Services (CCER-25-26-14). Results will be submitted to peer-reviewed journals and scientific meetings.Trial registration number ISRCTN14864451.

While lumbar multifidus (MF) muscle alterations are linked to low back pain (LBP), the structure-function relationship is not fully understood. This study aims to evaluate the relationship between fatty degeneration of the lumbar MF muscle and its function in individuals with and without LBP. The study included 25 participants with chronic nonspecific LBP and 25 age- and sex-matched healthy controls. Participants underwent MRI assessment for MF fat infiltration, utilizing IDEAL fat-water images. Ultrasound measures evaluated MF function, including shear-wave elastography (SWE) for stiffness/elasticity and thickness ratio from rest to submaximal contraction. All measurements were acquired at L4/L5 and L5/S1 spinal levels, bilaterally. Bivariate and multivariable linear regression models were used to assess the relationship between morphology and function, while age, sex, body max index (BMI), physical activity levels, and LBP status were considered as covariates. Fifty participants (26 females) were included (mean age: 39.22 ± 11.67). Greater

Background: Chronic low back pain (CLBP) patients present with morphological and functional deficits to the lumbar multifidus. Electromyostimulation (EMS) can be used to improve activation and strength in atrophied skeletal muscle, but its effect on multifidus morphology and function in CLBP patients is understudied. The aims of this study were to compare the effect of two EMS protocols on lumbar multifidus morphology, function, and patient-reported outcomes. Methods: Two-arm randomized control trial (RCT). Individuals with CLBP were randomized to receive either the ‘phasic’ or ‘combined’ muscle therapy protocol with the StimaWELL 120MTRS, a medium-frequency EMS device. T-tests and non-parametric equivalents were used to assess change in imaging-based outcomes, and a repeated-measures ANOVA was used for patient-reported outcomes. Results: Apart from a significant within-group decrease in fatty infiltration at left L5-S1 in the combined group (MD = −1.51, 95% CI = −2.79, −0.23, p = 0.024), results revealed no significant within- or between-group changes to multifidus morphology or function. Pairwise comparisons revealed that both groups experienced significant improvements in multiple pain outcome measures, with a significant group*time effect for LBP with sitting (p = 0.019) and pain interference (p = 0.032) in favor of the phasic group. Additionally, there were significant improvements in the phasic group in disability, pain interference, and pain catastrophizing (all p < 0.01). Conclusions: A 10-week EMS intervention produced no between-group differences in multifidus muscle morphology or function. Participants in both groups experienced significant improvements in a variety of patient-reported outcomes.

Low back pain (LBP) is a disabling disease and a public health concern. Aquatic exercise is an alternative form of exercise with less spinal loading and difficulty performing movements, benefiting those with pain-related fear. This study aimed to investigate the effect of an aquatic exercise program (SwimEx) versus standard care (SC) on lumbar paraspinal muscle volume and composition, strength and patient outcomes in individuals with chronic LBP. This randomized controlled trial included 34 participants with chronic LBP. Participants were randomly allocated to each group (SwimEx, n = 18; SC, n = 16) and underwent a 10-week supervised intervention program twice per week. Magnetic resonance imaging was performed at baseline and 10-weeks to examine the impact of each intervention on multifidus (MF) and erector spinae (ES) muscle volume (cm3) and fatty infiltration (% FI) at L1-L2, L2-L3, L3-L4, L4-L5, and L5-S1. Mixed model repeated measures ANCOVA revealed no significant time*group interactions for MF and ES volume and %FI. SwimEX had significant increases in MF volume at L2-L3 and L3-L4, and ES volume at L1-L2. Furthermore, SwimEX also had a significant increase in MF %FI at L2-L3. Both groups displayed significant increases in lumbar strength. Correlations between muscle morphology and patient outcomes showed improvements in MF volume were moderately correlated with an increase in physical quality of life and decrease in anxiety/depression. Interestingly, improvements in MF volume, MF %FI, and ES %FI, were each moderately correlated with a decrease in sleep disturbance. In conclusion, aquatic therapy may help increase lumbar paraspinal muscle volume and strength in participants with chronic LBP. Our findings support the notion that improvements in paraspinal muscle health are related to improvements in patient-reported outcomes. More imaging studies are required to examine the impact of exercise on overall paraspinal muscle health in chronic LBP and investigate these associations.

Study DesignProspective Randomized Controlled Trial.ObjectivesTo investigate the effect of combined motor control and isolated lumbar strengthening exercise (MC + ILEX) vs general exercise (GE) on upper lumbar paraspinal muscle volume and composition, strength and patient outcomes in individuals with chronic low back pain (LBP).Methods50 participants with nonspecific chronic LBP were randomly allocated (1:1) to each group (MC + ILEX or GE) and underwent a 12-week supervised intervention program 2 times per week. Magnetic resonance imaging was performed at baseline, 6-weeks and 12-weeks to examine the impact of each intervention on multifidus (MF) and erector spinae (ES) muscle volume (cm3) and fatty infiltration (%FI) at L1-L2, L2-L3 and L3-L4.ResultsOur results revealed no significant between-groups findings for MF and ES %FI and volume, and patient-reported psychosocial measures. However, both groups had significant within-groups decreases in MF %FI at L1-L2, L2-L3 and L3-L4, with concomitant decreases in MF volume at L1-L2 and L2-L3, and at L3-L4 in the GE group. Each group displayed significant improvements in Kinesiophobia, while only MC + ILEX had significant improvements in pain catastrophizing, anxiety, depression and sleep. Lastly, significant correlations were found between change in Kinesiophobia and upper lumbar MF %FI, and between change in strength and lower lumbar MF and ES size.ConclusionsBoth exercise interventions may help reduce upper lumbar MF %FI in individuals with chronic LBP, while MC + ILEX could significantly improve important patient outcomes. Our results support the idea that improvements in paraspinal muscle health associate with better patient outcomes. Further high-quality imaging studies are needed to explore these relationships.

IntroductionChronic low back pain (CLBP) is the leading cause of years lived with disability worldwide. Transcutaneous electrotherapies have been widely used to treat CLBP but, with the partial exception of transcutaneous electrical nerve stimulation (TENS), their effect on pain, disability, quality-of-life, and psychosocial outcomes have not been systematically reviewed. The purpose of this systematic review and meta-analysis was to clarify the overall effect of transcutaneous electrotherapies on patient-reported outcome measures (PROMs) in CLBP patients.MethodsFour databases and two study registries were searched for studies that utilized transcutaneous electrotherapies as a primary intervention for CLBP, compared against active or passive controls. Two reviewers independently extracted study data and assessed risk of bias. Studies were grouped by intervention vs. comparison, and by time of follow-up. Meta-analyses were conducted where appropriate.ResultsA total of 89 full-text were assessed for eligibility; 14 studies were included, with 6 in the meta-analyses (all TENS or mixed TENS). Pain: meta-analyses revealed no significant difference for TENS vs. active control, TENS vs. passive control, or mixed TENS vs. active control at post-intervention, nor for mixed TENS vs. active control at 1-month post-intervention. Interferential current (IFC) was more effective than active control (2 studies), while electromyostimulation (EMS) was generally superior to passive, but not active, controls (6 studies).DisabilityMeta-analyses revealed no significant difference for TENS vs. active control at post-intervention, mixed TENS vs. active control at post-intervention, or mixed TENS vs. active control at 1-month post-intervention. IFC was more effective than active control (2 studies), while the EMS results were mixed (6 studies). We were unable to perform meta-analyses for quality-of-life or psychosocial outcomes.ConclusionThere is moderate evidence that TENS is similar to all controls for improving pain and disability. There is limited evidence that IFC is superior to active controls for improving pain and disability. There is limited evidence that EMS is superior to passive but not active controls for improving pain, and similar to all controls for improving disability.Systematic Review Registrationhttps://www.crd.york.ac.uk/prospero/display_record.php?RecordID=452851, Identifier (CRD42023452851).

It remains unclear whether paraspinal muscle fatty infiltration in low back pain (LBP) is i) solely intramuscular, ii) is lying outside the epimysium between the muscle and fascial plane (epimuscular) or iii) or combination of both, as imaging studies often use different segmentation protocols that are not thoroughly described. Epimuscular fat possibly disturbs force generation of paraspinal muscles, but is seldomly explored. This project aimed to 1) compare epimuscular fat in participants with and without chronic LBP, and 2) determine whether epimuscular fat is different across lumbar spinal levels and associated with BMI, age, sex and LBP status, duration or intensity. Fat and water lumbosacral MRIs of 50 chronic LBP participants and 41 healthy controls were used. The presence and extent of epimuscular fat for the paraspinal muscle group (erector spinae and multifidus) was assessed using a qualitative score (0-5 scale; 0=no epimuscular fat and 5=epimuscular fat present along the entire muscle) and quantitative manual segmentation method. Chi-squared tests evaluated associations between qualitative epimuscular fat ratings and LBP status at each lumbar level. Bivariate and partial spearman’s rho correlation assessed relationships between quantitative and qualitative epimuscular fat with participants’ characteristics. Epimuscular fat was more frequent at the L4-L5 (X2= 13.781, p=0.017) and L5-S1 level (X2= 27.825, p<0.001) in participants with LBP compared to controls, which was not found for the higher lumbar levels. The total qualitative score (combined from all levels) showed a significant positive correlation with BMI, age, sex (female) and LBP status (r=0.23-0.55; p<0.05). Similarly, the total area of epimuscular fat (quantitative measure) was significantly correlated with BMI, age and LBP status (r=0.26-0.57; p<0.05). No correlations were found between epimuscular fat and LBP duration or intensity. Paraspinal muscle epimuscular fat is more common in chronic LBP patients. The functional implications of epimuscular fat should be further explored.

Chronic low back pain (CLBP) affects paraspinal muscle size, quality (e.g., fatty infiltration), range of motion (ROM), and strength. Although transcutaneous electrotherapies are used to treat CLBP, their effects on paraspinal-related outcomes are not fully known. The aim of this systematic review and meta-analysis was to assess the overall effect of transcutaneous electrotherapies on trunk/lumbar ROM, paraspinal muscle morphology, and trunk muscle function (including strength and endurance) in CLBP patients. A systematic search of four databases and two study registers was conducted between 1 February 2022 and 15 September 2022. Two reviewers were responsible for screening and data extraction. Of the 3939 independent records screened, 10 were included in the systematic review and 2 in the meta-analysis. The results suggest there is limited evidence that both EMS and EMS plus exercise are superior to passive and active controls, respectively, for improving trunk muscle endurance. There is limited evidence that neither TENS nor mixed TENS are superior to controls for improving trunk muscle endurance. There is limited evidence that NMES is superior to passive controls for improving trunk muscle strength. The effect of transcutaneous electrotherapy on the other investigated outcomes was inconclusive. Future transcutaneous electrotherapy studies should focus on paraspinal-based outcomes that are under-studied.

Purpose: The aim of this observational cross-sectional study was to examine correlations of intramuscular fat content in lumbar multifidus (LM) by comparing muscle echo intensity (EI) and percent fat signal fraction (% FSF) generated from ultrasound (US) and magnetic resonance (MR) images, respectively.Methods: MRI and US images from 25 participants (16 females, 9 males) selected from a cohort of patients with chronic low back pain (CLBP) were used. Images were acquired bilaterally, at the L4 and L5 levels (e.g., 4 sites). EI measurements were acquired by manually tracing the cross-sectional border of LM. Mean EI of three US images per site were analyzed (e.g., raw EI). A correction factor for subcutaneous fat thickness (SFT) was also calculated and applied (e.g., corrected EI). Corresponding fat and water MR images were used to acquire %FSF measurements. Intra-rater reliability was assessed by intraclass coefficients (ICC). Pearson correlations and simple linear regression were used to assess the relationship between %FSF, raw EI and corrected EI measurements.Results: The intra-rater ICCs for all measurements were moderate to excellent. Correlations between %FSF vs. raw EI and corrected EI were moderate to strong (0.40 < r < 0.52) and (0.40 < r < 0.51), respectively. Moderate correlations between SFT and EI were also identified.Conclusion: US is a low-cost, non-invasive, accessible, and reliable method to examine muscle composition, and presents a promising solution for assessing and monitoring the effect of different treatment options for CLBP in clinical settings.

Context : Measures of side-to-side asymmetry in body composition may help identify players who are predisposed to lower limb injuries (LLI) or lower back pain (LBP). This study aimed to examine (1) side-to-side asymmetry in college rugby players according to sex and position and (2) whether side-to-side asymmetry is associated with LBP or LLI. Design: Cross-sectional study.Methods: Thirty-six rugby players (61% female) underwent a dual-energy X-ray absorptiometry assessment for total and regional (appendicular, truncal) outcomes of fat mass, lean mass, and bone mass. A subsample (n = 23) of players had a second dualenergy X-ray absorptiometry assessment 2 months postbaseline. Two-way analysis of variance was used to assess the effect of position (forward and backs) and sex on body composition asymmetry. Student paired t tests were used to assess side-to-side difference in body composition and compare baseline and follow-up measures. Logistic regression was used to assess possible associations between LLI, LBP, and the degree of side-to-side asymmetry in body composition.Results: Male players had greater asymmetry in arm bone mass compared with female players (P = .026), and trunk fat mass asymmetry was greater in forwards as compared with backs (P = .017). Forwards had significantly greater fat mass (P = .004) and percentage of fat (P = .048) on the right leg compared with the left. Backs had significantly greater bone mass in the right arm compared with the left (P = .015). From baseline to postseason, forwards had a significant increase in side-to-side asymmetry in arm lean mass (P = .006) and a significant decrease in side-to-side asymmetry in leg fat mass (P = .032). In backs, side-to-side asymmetry at baseline compared with postseason was significantly different (P = .011) for trunk fat mass. There were no significant associations between body composition asymmetry, LLI, or LBP by sex or position.Conclusion: Our results revealed the presence of side-to-side asymmetries in body composition in university rugby players between sex and position. The amount of asymmetry, however, was not associated with LBP and LLI.

Purpose The purpose of this study was to evaluate the agreement between paraspinal muscle composition measurements obtained from fat–water images using % fat-signal fraction (%FSF) in comparison to those obtained from T2-weighted magnetic resonance images (MRI) using a thresholding method. Methods A sample of 35 subjects (19 females, 16 males; 40.26 ± 11.3 years old) was selected from a cohort of patients with chronic low back pain (LBP). Axial T2-weighted and IDEAL (Lava-Flex, 2 echo sequence) fat and water MR images were obtained using a 3.0 Tesla GE scanner. Multifidus, erector spinae, and psoas major muscle composition measurements were acquired bilaterally at L4–L5 and L5–S1 using both imaging sequences and related measurement methods. All measurements were obtained by the same rater, with a minimum of 7 days between each method. Intra-class correlation coefficients (ICCs) were calculated to assess intra-rater reliability. Pearson Correlation and Bland–Altman 95% limits of agreement were used to assess the agreement between both measurement methods. Results The intra-rater reliability was excellent for all measurements with ICCs varying between 0.851 and 0.997. Strong positive correlations indicating a strong relationship between composition measurements were obtained from fat–water and T2-weighted images for bilateral multifidus and erector spinae muscles at both spinal levels and the right psoas major muscle at L4–L5, with correlation coefficient r ranging between 0.67 and 0.92. Bland–Altman plots for bilateral multifidus and erector spinae muscles at both levels revealed excellent agreement between the two methods, however, systematic differences between both methods were evident for psoas major fat measurements. Conclusion Our findings suggest that utilizing fat–water and T2-weighted MR images are comparable for quantifying multifidus and erector spinae muscle composition but not of the psoas major. While this suggests that both methods could be used interchangeably for the multifidus and erector spinae, further evaluation is required to expand and confirm our findings to other spinal levels.

Background Low back pain (LBP) is one of the most disabling diseases and a major health issue. Despite the evidence of a link between paraspinal and gluteal muscle dysfunction and LBP, it is unknown whether aquatic exercises can lead to improvements in paraspinal and gluteal muscle morphology and function, and whether improvements in overall muscle health are associated with improvements in patients’ outcomes. The unique properties of water allow a water-based exercise program to be tailored to the needs of those suffering from LBP. This study uses magnetic resonance imaging (MRI) to investigate the effect of an aquatic exercise program versus standard exercise on 1) paraspinal and gluteal muscle size, quality and strength and 2) pain, disability, and psychological factors (pain related fear, depression, anxiety, sleep quality) in chronic LBP. Methods This study will include 34 participants with chronic non-specific LBP and moderate to severe disability, aged between 18 and 65, who will be randomly assigned (1:1) to the aquatic exercise group or land-based standard care exercise group. Both groups will receive 20 supervised sessions, twice per week over 10 weeks. MRIs will be obtained along the lumbosacral spine (L1-L5) and pelvis at the start and end of the intervention to assess the effect of each exercise intervention on paraspinal and gluteal muscle size and quality. Pre- to post-intervention changes in all outcomes between each group will be assessed, and the association between the changes in back muscle quality and clinical outcomes will be examined. 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 This study will determine if water-based exercises targeting the lower back and gluteal muscles can lead to important changes in muscle quality and function, and their possible relation with patients’ pain and functional improvements. Our findings will have strong clinical implications and provide preliminary data to design a community program to better support individuals with chronic LBP. Trial registration NCT05823857, registered prospectively on April 27 th , 2023.

OBJECTIVES To compare, in individuals with chronic obstructive pulmonary disease (COPD): 1) the effects of 12 weeks of continuous training at high intensity (CTHI), continuous training at the ventilatory threshold (CTVT) and high-intensity interval training (HIIT) on cognition; and 2) the maintenance of these effects at a 1-year follow-up. METHODS Participants were randomized to CTHI, CTVT, or HIIT and underwent 12 weeks of three times weekly training on cycle ergometers. Training intensity and duration were set based on group allocation. At program completion, all participants were given standardized exercise recommendations from the exercise supervisors, but no active maintenance intervention was offered. Assessments were made at baseline (week 0), program completion (week 12) and 1 year after baseline (year 1). Cognition was assessed with a neuropsychological testing battery and the Montreal Cognitive Assessment (MoCA). RESULTS In 36 participants (64% women, mean age: 67.5 +/- 9 years) with moderate COPD (FEV1: 59 +/- 17% predicted), the 12-week effects of exercise training on cognition were small (Cohen'sd(z): -0.063-0.448). One exception was the Rey-O Complex Figure (copy), assessing visuoconstructive abilities, in which larger effects were detected, especially in participants with mild cognitive impairment at baseline (Cohen'sd(z)= 1.122, 95% CI[0.406, 1.809]). Between intervention groups, results were heterogeneous. CTHI was the only group with medium-to-large effects in each cognitive domain. At year 1, gains and losses in cognition were seen across groups. CONCLUSION In COPD, 12 weeks of exercise training led to small changes in cognition, with heterogeneity between exercise protocols and across cognitive domains.

Background and Objectives: Ultrasound echo intensity (EI) of the lumbar multifidus muscle (LMM) could offer valuable insights regarding muscle quality in people with low back pain (LBP). However, whether the rater’s experience noticeably influences the reliability and precision of LMM EI measurements has not been established. The aims of this study were to investigate the intra-rater and inter-rater reliability of LMM EI measurements, and to compare the reliability and SEM between a novice and an experienced rater. Materials and Methods: Twenty athletes (10 females, 10 males) with a history of LBP were included in this study. Transverse ultrasound images of LMM were taken at L5 in prone. LMM EI measurements were obtained bilaterally by tracing the maximum ROI representing the LMM cross-sectional area (CSA), avoiding the inclusion of bone or surrounding fascia. All measurements were performed by two novice raters and an experienced researcher. Each measurement was acquired by each rater three times for each side on three different images, and the average was used in the analyses. Raters were blinded to each other’s measurements and the participant’s clinical information. Intra-class correlation coefficients (ICCs) were obtained to assess the intra-rater and inter-rater reliability. Results: The intra-rater ICC values for the LMM measurements for the experienced rater were excellent (ICC all > 0.997). The inter-rater reliability ICC values showed moderate to excellent reliability (0.614 to 0.994) and agreement between the novice raters and the experienced rater, except for Novice 1 for the right LMM, which revealed lower ICCs and a wider 95% CI. Intra-rater and inter-rater reliability results were similar when separately looking at the right and left side of the muscle and participant gender. Conclusions: Our findings support the clinical use of ultrasound imaging for the assessment of LMM EI in individuals with LBP.