Reliability of a Trunk Flexion and Extensor Muscle Strength Test with Hand-Held and Isokinetic Dynamometers in Female Athletes.

An accurate trunk muscle strength assessment seems very important to design and individualize training and rehabilitation programs in clinical and sport settings. Hand-held dynamometers (HHDs) are interesting alternatives to isokinetic dynamometers for assessing trunk isometric muscle strength because they are inexpensive instruments and easy to use. This cross-sectional observational study aimed to examine the reliability of two novel sitting tests for assessing trunk flexion and extension isometric strength using an HHD and their relationship with two other novel isometric tests that use an isokinetic dynamometer. Twenty-four female amateur athletes (age: 24.5 ± 2.64 years; body height: 164.45 ± 6.33 cm; body mass: 63.17 ± 10.35 kg) participated in this study. A test-retest design was carried out one-week apart to examine the reliability. The relationship and the degree of agreement between the HHD and the isokinetic dynamometer measurements were analysed using Pearson correlation and Bland-Altman analysis, respectively. In general, the reliability of all isometric strength tests was good, with ICCs ranging from 0.65 to 0.87 and typical error < 15%. Pearson correlations were moderate, with values of r = 0.47 (R2 = 0.22) and r = 0.42 (R2 = 0.18) for flexion and extension strength, respectively. Bland-Altman plots showed no agreement between HHDs and isokinetic measurements. All trunk isometric tests using both, an isokinetic dynamometer and HHDs, provide reliable measurements for assessing trunk flexion and extension strength. According to the comparative analysis, both measurement types are different and cannot be used interchangeably. Health and sport professionals should choose the test that best suits the biomechanical characteristics required for functional goals or success in a given sport.

Data-Monitoring Solution for Desalination Processes: Cooling Tower and Mechanical Vapor Compression Hybrid System.

The advancement of novel water treatment technologies requires the implementation of both accurate data measurement and recording processes. These procedures are essential for acquiring results and conducting thorough analyses to enhance operational efficiency. In addition, accurate sensor data facilitate precise control over chemical treatment dosages, ensuring optimal water quality and corrosion inhibition while minimizing chemical usage and associated costs. Under this framework, this paper describes the sensoring and monitoring solution for a hybrid system based on a cooling tower (CT) connected to mechanical vapor compression (MVC) equipment for desalination and brine concentration purposes. Sensors connected to the data commercial logger solution, Almemo 2890-9, are also discussed in detail such as temperature, relative humidity, pressure, flow rate, etc. The monitoring system allows remote control of the MVC based on a server, GateManager, and TightVNC. In this way, the proposed solution provides remote access to the hybrid system, being able to visualize gathered data in real time. A case study located in Cartagena (Spain) is used to assess the proposed solution. Collected data from temperature transmitters, pneumatic valves, level sensors, and power demand are included and discussed in the paper. These variables allow a subsequent forecasting process to estimate brine concentration values. Different sample times are included in this paper to minimize the collected data from the hybrid system within suitable operation conditions. This solution is suitable to be applied to other desalination processes and locations.

Trunk postural control during unstable sitting among individuals with and without low back pain: A systematic review with an individual participant data meta-analysis.

INTRODUCTION: Sitting on an unstable surface is a common paradigm to investigate trunk postural control among individuals with low back pain (LBP), by minimizing the influence lower extremities on balance control. Outcomes of many small studies are inconsistent (e.g., some find differences between groups while others do not), potentially due to confounding factors such as age, sex, body mass index [BMI], or clinical presentations. We conducted a systematic review with an individual participant data (IPD) meta-analysis to investigate whether trunk postural control differs between those with and without LBP, and whether the difference between groups is impacted by vision and potential confounding factors. METHODS: We completed this review according to PRISMA-IPD guidelines. The literature was screened (up to 7th September 2023) from five electronic databases: MEDLINE, CINAHL, Embase, Scopus, and Web of Science Core Collection. Outcome measures were extracted that describe unstable seat movements, specifically centre of pressure or seat angle. Our main analyses included: 1) a two-stage IPD meta-analysis to assess the difference between groups and their interaction with age, sex, BMI, and vision on trunk postural control; 2) and a two-stage IPD meta-regression to determine the effects of LBP clinical features (pain intensity, disability, pain catastrophizing, and fear-avoidance beliefs) on trunk postural control. RESULTS: Forty studies (1,821 participants) were included for the descriptive analysis and 24 studies (1,050 participants) were included for the IPD analysis. IPD meta-analyses revealed three main findings: (a) trunk postural control was worse (higher root mean square displacement [RMSdispl], range, and long-term diffusion; lower mean power frequency) among individuals with than without LBP; (b) trunk postural control deteriorated more (higher RMSdispl, short- and long-term diffusion) among individuals with than without LBP when vision was removed; and (c) older age and higher BMI had greater adverse impacts on trunk postural control (higher short-term diffusion; longer time and distance coordinates of the critical point) among individuals with than without LBP. IPD meta-regressions indicated no associations between the limited LBP clinical features that could be considered and trunk postural control. CONCLUSION: Trunk postural control appears to be inferior among individuals with LBP, which was indicated by increased seat movements and some evidence of trunk stiffening. These findings are likely explained by delayed or less accurate corrective responses. SYSTEMATIC REVIEW REGISTRATION: This review has been registered in PROSPERO (registration number: CRD42021124658).

Trunk muscle activation in prone plank exercises with different body tilts.

BACKGROUND: Body tilt changes could affect the intensity/difficulty of core stability exercises, but there is still a lack of knowledge about its impact. OBJECTIVE: To analyse the trunk muscles activation during prone plank exercises at different body tilts. METHODS: Twenty-four young adults who performed recreational gymnastic activities participated in this study. Electromyography activity of the rectus abdominis (RA), external oblique (EO), internal oblique (IO) and erector spinae (ES) was recorded during the performance of six variations of the prone plank exercise (planking with feet supported on the ground [conventional horizontal position] and planking with feet supported on wall bars at five different heights increasing the angle tilt) and an inverted position exercise. RESULTS: The RA, EO and IO activation in all prone plank variations were higher than those observed in the conventional prone plank. In addition, the coefficient of variation of the muscle activation increased with the declination angle, reaching the highest values in the inverted position for the RA and ES muscles. CONCLUSION: The results seem to indicate that the body tilt variation could be used as an easy and inexpensive strategy for modulating the neuromuscular demands and the motor control challenge during planking exercises.

Exercise Intensity Progressions and Criteria to Prescribe Core Stability Exercises in Young Physically Active Men: A Smartphone Accelerometer-Based Study.

ABSTRACT: Heredia-Elvar, JR, Juan-Recio, C, Prat-Luri, A, Barbado, D, Ríos-Calonge, Jdl, and Vera-Garcia, FJ. Exercise intensity progressions and criteria to prescribe core stability exercises in young physically active men: a smartphone accelerometer-based study. J Strength Cond Res 38(2): 266-273, 2024-The establishment of core stability (CS) exercise intensity progressions in sport and clinical settings is normally based on subjective criteria. Therefore, this study aimed to develop exercise intensity progressions for some of the most common CS exercises through smartphone accelerometry and to analyze the effect of the subjects' lumbopelvic postural control on these progressions. Fifty-seven healthy young physically active male students performed 7 isometric variations of front bridge, back bridge, side bridge, and bird-dog exercises with a smartphone accelerometer placed on the pelvis. Mean pelvic accelerations were calculated during each variation to evaluate the lumbopelvic postural control challenge imposed on the subjects as an index of exercise intensity of difficulty. For the bridge exercises, long bridging produced higher pelvic accelerations than short bridging, bridging with single-leg support was more intense than bridging with double-leg support (even with both legs on a hemisphere ball for the back and front bridge), and the most difficult variations were those performed on a Swiss ball, mainly the variations with single-leg support. For the bird-dog exercise, the 2-point positions were more intense than the 3-point positions, the variations performed with a knee on the hemisphere ball produced higher pelvic accelerations than similar variations performed with the forearm on the hemisphere ball, and the variations with limb motions generated higher pelvic accelerations than similar variations performed without limb motions. Although the CS exercise progressions were very similar across subjects, our results showed the need to individualize the prescription of the CS exercise progressions based on the subjects' lumbopelvic postural control level.

Smartphone accelerometry for quantifying core stability and developing exercise training progressions in people with multiple sclerosis.

BACKGROUND: Core stability exercise programs have become popular in recent years for preserving balance and functional independence in people with multiple sclerosis (PwMS); however, their real impact is not well-known as the main intervention target (i.e., core stability) theoretically responsible for balance or functional improvements is not measured. The objective of this study was to test the reliability of accelerometers integrated into smartphones for quantifying core stability and developing exercise progressions in PwMS. METHODS: Twenty participants with MS [age: 47.5±8.0 years; height: 1.62±0.07 m; mass: 63.4±10.9 kg; EDSS: 3.0 (1.5-6)] participated voluntarily in this study. CS was assessed in different variations of the front, side, and back bridges and bird-dog exercises by measuring the mean lumbopelvic acceleration in two testing sessions, separated by one week. Relative and absolute reliability of lumbopelvic acceleration of those exercise variations performed by more than 60% of the participants was analyzed by the intraclass correlation coefficient (ICC3,1), and the standard error of measurement (SEM) and the minimal detectable change (MDC), respectively. Repeated measures ANOVAs were performed to detect a potential learning effect between test-retest assessments. Statistical significance was set at p < 0.05. RESULTS: Reliability analyses revealed that good to excellent relative and absolute scores (0.850.05). CONCLUSION: Smartphone accelerometry seems a low cost, portable and easy-to-use tool to objectively and reliably track core stability changes in PwMS through. However, in spite of the popularity of bridging and bird-dog exercises, only the short and long bridges and the three-point bird-dog positions proved feasible for most participants. Overall, this study provides useful information to evaluate and guide the prescription of core stability exercise programs in PwMS with mild-to-moderate impairment.

A Thematic Survey on the Reporting Quality of Randomized Controlled Trials in Rehabilitation: The Case of Multiple Sclerosis.

BACKGROUND AND PURPOSE: Optimal reporting is a critical element of scholarly communications. Several initiatives, such as the EQUATOR checklists, have raised authors' awareness about the importance of adequate research reports. On these premises, we aimed at appraising the reporting quality of published randomized controlled trials (RCTs) dealing with rehabilitation interventions. Given the breadth of such literature, we focused on rehabilitation for multiple sclerosis (MS), which was taken as a model of a challenging condition for all the rehabilitation professionals.A thematic methodological survey was performed to critically examine rehabilitative RCTs published in the last 2 decades in MS populations according to 3 main reporting themes: (1) basic methodological and statistical aspects; (2) reproducibility and responsiveness of measurements; and (3) clinical meaningfulness of the change. SUMMARY OF KEY POINTS: Of the initial 526 RCTs retrieved, 370 satisfied the inclusion criteria and were included in the analysis. The survey revealed several sources of weakness affecting all the predefined themes: among these, 25.7% of the studies complemented the P values with the confidence interval of the change; 46.8% reported the effect size of the observed differences; 40.0% conducted power analyses to establish the sample size; 4.3% performed retest procedures to determine the outcomes' reproducibility and responsiveness; and 5.9% appraised the observed differences against thresholds for clinically meaningful change, for example, the minimal important change. RECOMMENDATIONS FOR CLINICAL PRACTICE: The RCTs dealing with MS rehabilitation still suffer from incomplete reporting. Adherence to evidence-based checklists and attention to measurement issues and their impact on data interpretation can improve study design and reporting in order to truly advance the field of rehabilitation in people with MS.Video Abstract available for more insights from the authors (see the Video, Supplemental Digital Content 1 available at: http://links.lww.com/JNPT/A424 ).

Effect of Trunk-Focused Exercises on Pain, Disability, Quality of Life, and Trunk Physical Fitness in Low Back Pain and How Potential Effect Modifiers Modulate Their Effects: A Systematic Review With Meta-analyses.

OBJECTIVE: To analyze the effect of trunkfocused exercise programs (TEPs) and moderator factors on chronic nonspecific low back pain (LBP). DESIGN: Systematic review with meta-analyses. LITERATURE SEARCH: We searched the PubMed, Scopus, Embase, SPORTDiscus, and CENTRAL databases from their inception to June 2022. STUDY SELECTION CRITERIA: We included randomized controlled trials comparing TEPs to control or general exercises. DATA SYNTHESIS: We used random-effects models to calculate the standardized mean difference (SMD) plus confidence interval (CI) and heterogeneity (I2) for pain, disability, quality of life, and trunk performance. The impact of moderator factors was analyzed through meta-regression. RESULTS: Forty randomized controlled trials (n = 2391) were included. TEPs showed positive effects for all outcomes versus control (SMD 0.90-2.46; 95% CI, -0.04 to 4.96; I2 61%-98%). There were small effects in favor of TEPs versus general exercises for pain (SMD = 0.20; 95% CI, 0.03-0.37; I2 = 13.4%) and disability (SMD = 0.20; 95% CI, 0.02-0.38; I2 = 0%). Trunk and/or hip range-of-motion improvements were associated with greater reductions in pain (P<.01; ß = 0.56; 95% CI, 0.25-0.87) and disability (P<.01; ß = 0.66; 95% CI, 0.27-1.05). Low body mass was associated with higher pain reduction (P = .03; ß = -0.17; 95% CI, -0.32 to -0.02). CONCLUSIONS: Trunk-focused exercise programs had positive effects on pain, disability, quality of life, and trunk performance compared to control groups, and on pain and disability compared to general exercises. Increasing trunk and/or hip range of motion was associated with greater pain and disability reduction, and lower body mass with higher pain reduction. J Orthop Sports Phys Ther 2023;53(2):64-93. Epub: 16 January 2023. doi:10.2519/jospt.2023.11091.

Is the Side Bridge Test Valid and Reliable for Assessing Trunk Lateral Flexor Endurance in Recreational Female Athletes?

The side bridge test (SBT) is one of the most popular tests to assess isometric trunk lateral flexor endurance. The aim of this study was to assess the validity and reliability of the SBT in healthy females. Twenty-four (24.58 ± 3.92 years) physically active (1-2 h of moderate physical activity, 2-3 times a week) females voluntarily participated in this study. The surface electromyography (EMG) of eight abdominal, back, shoulder and hip muscles was measured during the SBT. Normalized median frequency slopes (NMFslope) were calculated to analyze the muscle fatigue. The EMG amplitudes were normalized to maximum EMG values to assess muscle activity intensity. A one-week test-retest design was performed to evaluate the SBT reliability through the ICC3,1 and typical error. Higher NMFslopes and normalized EMG amplitudes were found in deltoids, abdominal obliques, rectus abdominis, and erector spinae in comparison to latissimus dorsi, gluteus medius, and rectus femoris. However, no significant differences were found between the trunk lateral flexors and the deltoids. Linear regression analysis showed that SBT performance could be significantly predicted by external oblique and deltoid NMFslope (adjusted R2 = 0.673) and by body mass and trunk height (adjusted R2 = 0.223). Consistency analysis showed a high intraclass correlation coefficient (0.81) and a relatively high typical error (10.95 s). Despite the good relative reliability of the SBT, its absolute reliability was low and its validity questionable, as the shoulder muscle activation and fatigue and the individuals' anthropometric characteristics played an important role in SBT performance.

Observational Screening Guidelines and Smartphone Accelerometer Thresholds to Establish the Intensity of Some of the Most Popular Core Stability Exercises.

The lack of training load control, mainly exercise intensity, is one of the main limitations of core stability (CS) programs, which makes the training individualization and the analysis of the dose-response relationship difficult. The objectives of this study were to assess the inter-and intra-rater agreement when using new observational screening guidelines to decide if a core stability exercise represents an adequate training intensity level for a given participant. Besides, the relationship between experts' ratings based on these criteria and pelvic accelerations recorded with a smartphone accelerometer was also analyzed. Ten healthy physically active participants with a smartphone accelerometer placed on their pelvis were video-taped while performing a progression of seven variations of the front bridge, back bridge, side bridge and bird-dog exercises. Two expert and four non-expert raters watched the videos and used the observational screening guidelines to decide for each exercise variation if it represented an adequate training intensity level or not. In order to analyze the inter-and intra-rater agreement, several Kappa (κ) statistics were used. Receiver operating characteristic (ROC) curves to explore if the accelerometry allowed to establish pelvic acceleration thresholds representing the minimum level of exercise intensity for CS training. Cut-off acceleration values were calculated balancing sensitivity (Se) and 1-specifity (1-Sp) indexes (i.e., Youden index) or minimizing 1-Sp. The intra-and inter-rater analysis showed a substantial-high level of agreement with a prevalence-adjusted bias-adjusted Kappa > 0.69. The ROC curves showed that the acceleration thresholds for the bridging exercises were very similar, with global cut-off values of 0.35 m/s2 (Se = 82%; 1-Sp = 15%) when using the Youden Index and of 0.50 m/s2 when minimizing 1-Sp (Se = 31%), whilst the bird-dog exercise showed lower cut-off values (Youden Index: 0.21 m/s2, Se = 90%, 1-Sp = 16%; minimizing 1-Sp: 0.32 m/s2, Se = 40%). Overall, this study provides observational screening guidelines and smartphone accelerometer thresholds to facilitate the decision-making process when setting the intensity of some of the most popular core stability exercises in young physically active individuals.

Heart rate-based indices to detect parasympathetic hyperactivity in functionally overreached athletes. A meta-analysis.

Investigations into the sensitivity of heart rate-(HR) derived indices for tracking parasympathetic nervous system (PNS) changes in functionally overreached (F-OR) endurance-trained athletes have produced equivocal findings. Lack of clarity may be a result of methodological inconsistencies. Therefore, the aims of this systematic review and meta-analysis were (a) to determine the sensitivity of resting and post-exercise vagal-related HR variability (HRV) and HR recovery (HRR) indices to detect PNS modulation in F-OR and non-overreached (non-OR) athletes, and (b) to investigate the influence of methodological factors on the sensitivity of HR-based indices to detect PNS hyperactivity in F-OR athletes. We searched CENTRAL, Scopus, PubMed, Embase, and Web of Science up to May 2020 for the following terms: male and female endurance-trained athletes, controlled and uncontrolled studies that carried out an overload training period, and PNS modulation measured in resting and post-exercise, pre- and post-overload training period. A random-effects model of standardized mean difference (SMD) was estimated for each outcome measure based on the training-induced fatigue status (F-OR vs non-OR athletes), and the influence of methodological issues to detect PNS hyperactivity in F-OR was assessed by subgroup analyses. Pooled analysis showed that resting vagal-related HRV indices did not detect PNS hyperactivity in F-OR athletes (SMD+ = -0.01; 95% confidence interval [CI] = -0.51, 0.50), and no statistical difference (P = .600) was found with non-OR athletes (SMD+ = 0.15; 95% CI = -0.14, 0.45). However, subgroup analysis based on HRV parameter showed a moderate statistical increase in weekly averaged HRV in F-OR athletes (SMD+ = 0.81; 95% CI = 0.35, 1.26), while isolated HRV values did not reach statistical significance (SMD+ = -0.45; 95% CI = -0.96, 0.06). We observed a moderate and statistically significant increase in HRR indices among F-OR athletes (SMD+ = 0.65; 95% CI = 0.44, 0.87), no changes for non-OR athletes (SMD+ = 0.10; 95% CI = -0.15, 0.34), and statistically significant differences between F-OR and non-OR athletes (P < .001). Insufficient data prevented meta-analysis for post-exercise vagal-related HRV indices. Our findings show that when methodological factors are considered, HR-based indices are sensitive to increased PNS modulation in F-OR.

Test-Retest Reliability and Known-Groups Validity of Trunk Muscle Tests in People With Multiple Sclerosis: A Cross-Sectional, Case-Control Study.

OBJECTIVE: Research on muscle performance testing reliability in people with multiple sclerosis (MS) has focused on limb performance while less is known about trunk strength and endurance. This work aims to 1) establish test-retest reliability of trunk flexion, lateral flexion, and extension strength tests, and plank, side bridge, and Biering-Sørensen endurance tests in people with MS and matched healthy controls (HCs); 2) analyze known-groups validity of these tests in people with MS and HCs; 3) to compare groups for side-to-side differences; and 4) to describe the relationships between trunk performance and functional mobility tests. METHODS: Fifteen people with MS (median Expanded Disability Status Scale = 3) and 15 HCs underwent 2 trunk isometric strength and endurance testing sessions. Mobility was evaluated by Timed Up-and-Go test. Intraclass correlation coefficient, SEM, and minimal detectable change (MDC) were calculated. Between-group differences in trunk performance were tested using the t test for independent measures. Between-group differences in an asymmetry index were analyzed by independent t test. Bivariate correlations between trunk tests and mobility were also examined. RESULTS: All trunk tests showed good-to-excellent relative reliability in both groups (intraclass correlation coefficient > 0.71). Regarding absolute reliability, strength tests were associated with low intersession variability in both groups (MDC: MS, 11.23%-36.45%; HCs, 26.60%-31.98%). Conversely, endurance tests showed higher variability scores in people with MS (MDC: MS, 69.55%-116.50%; HCs, 29.57%-54.40%). People with MS displayed significantly lower trunk performance. Likewise, the asymmetry index showed significantly higher scores in people with MS for endurance assessment but not in strength tests. Significant correlations were detected in people with MS between Timed Up-and-Go and several trunk tests (r = 0.63-0.70). CONCLUSIONS: SEM and MDC scores revealed similar consistency and variability between groups for strength tests, whereas higher variability was observed for endurance tests in people with MS. Trunk strength tests are reliable and present discriminant validity to distinguish mildly disabled people with MS from HCs. Conversely, the high measurement error and variability of the endurance tests may hinder their application in intervention programs. IMPACT: Determining the reliability and validity of the tests currently used to assess trunk function is of the greatest importance for people with MS (who show not only impaired trunk function but also wide fluctuations in performance), as it requires consistent and accurate measurements that are sensitive enough to detect minimal changes induced by rehabilitation.

Impact of COVID-19 Confinement on Physical Activity and Sedentary Behaviour in Spanish University Students: Role of Gender.

During the COVID-19 pandemic, entire populations were instructed to live in home-confinement to prevent the expansion of the disease. Spain was one of the countries with the strictest conditions, as outdoor physical activity was banned for nearly two months. This study aimed to analyse the changes in physical activity and sedentary behaviours in Spanish university students before and during the confinement by COVID-19 with special focus on gender. We also analysed enjoyment, the tools used and motivation and impediments for doing physical activity. An online questionnaire, which included the International Physical Activity Questionnaire Short Form and certain "ad hoc" questions, was designed. Students were recruited by distributing an invitation through the administrative channels of 16 universities and a total of 13,754 valid surveys were collected. Overall, university students reduced moderate (-29.5%) and vigorous (-18.3%) physical activity during the confinement and increased sedentary time (+52.7%). However, they spent more time on high intensity interval training (HIIT) (+18.2%) and mind-body activities (e.g., yoga) (+80.0%). Adaptation to the confinement, in terms of physical activity, was handled better by women than by men. These results will help design strategies for each gender to promote physical activity and reduce sedentary behaviour during confinement periods.

Exercise-based cardiac rehabilitation and parasympathetic function in patients with coronary artery disease: a systematic review and meta-analysis.

PURPOSE: The effects of exercise-based cardiac rehabilitation (CR) on parasympathetic modulation are controversial. This systematic review and meta-analysis aims to (a) determine the effect of exercise-based CR on heart-rate-derived indices associated with cardiac parasympathetic modulation in resting and post-exercise conditions in coronary artery disease (CAD) patients and (b) identify the possible moderator variables of the effect of exercise-based CR on parasympathetic modulation. METHODS: We searched CENTRAL and Web of Science up to November 2018 for the following terms: adult CAD patients, controlled exercise-based CR interventions and parasympathetic modulation measured in resting (vagal-related heart rate variability [HRV] indices of the root mean square of the differences in successive in RR interval [RMSSD] and high frequency [HF]) and post-exercise (heart rate recovery [HRR]) pre- and post-intervention. We estimated a random-effects model of standardised mean difference (SMD) and mean difference (MD) for vagal-related HRV indices and HRR, respectively. We assessed the influence of categorical and continuous variables. RESULTS: The overall effect size showed significant differences in RMSSD (SMD+ = 0.30; 95% confidence interval [CI] = 0.12-0.49) and HRR (MD+ = 5.35; 95% CI = 4.08-6.61 bpm) in favour of the exercise-based CR group. The overall effect size showed no differences in HF between groups (SMD+ = 0.14; 95% CI, -0.12-0.40). Heterogeneity analyses reached statistical significance, with high heterogeneity for HF (p < 0.001; I2 = 70%) and HRR (p < 0.001; I2 = 85%). Analysis of the moderator variables showed that the effect on HRR is greater in young patients (p = 0.008) and patients treated with percutaneous intervention (p = 0.020). CONCLUSIONS: Exercise-based CR improves the post-exercise parasympathetic function, with greater effects in younger CAD patients and in those who were revascularised with percutaneous intervention. The effects on resting parasympathetic function are more controversial due to methodological inconsistencies in measuring HRV, with the use of RMSSD recommended instead of HF because its results show higher consistency. Future studies involving women, focusing on methodological issues, and performing other training methods are needed to increase our knowledge about this topic.

Are the Current Cardiac Rehabilitation Programs Optimized to Improve Cardiorespiratory Fitness in Patients? A Meta-Analysis.

Previous meta-analyses have shown that high-intensity interval training (HIIT) is more suitable than moderate continuous training (MCT) for improving peak oxygen uptake (VO2peak) in patients with coronary artery disease. However, none of these meta-analyses have tried to explain the heterogeneity of the empirical studies in optimizing cardiac rehabilitation programs. Therefore, our aims were (a) to estimate the effect of MCT and HIIT on VO2peak, and (b) to find the potential moderator variables. A search was conducted in PubMed, Scopus, and ScienceDirect. Out of the 3,110 references retrieved, 29 studies fulfilled the selection criteria to be included in our meta-analysis. The mean difference was used as the effect size index. Our results showed significant enhancements in VO2peak after cardiac rehabilitation based on MCT and HIIT (mean difference = 3.23; 95% confidence interval [2.81, 3.65] ml·kg-1·min-1 and mean difference = 4.61; 95% confidence interval [4.02, 5.19] ml·kg-1·min-1, respectively), with greater increases after HIIT (p < .001). Heterogeneity analyses reached statistical significance with moderate heterogeneity for MCT (p < .001; I2 = 67.0%), whereas no heterogeneity was found for the effect of HIIT (p = .220; I2 = 22.0%). Subgroup analyses showed significant between-group heterogeneity of the MCT-induced effect based on the training mode (p < .001; I2 = 90.4%), the risk of a new event (p = .010; I2 = 77.4%), the type of cardiovascular event (p = .009; I2 = 84.8%), the wait time to start cardiac rehabilitation (p = .010; I2 = 76.6%), and participant allocation (p = .002; I2 = 89.9%). Meta-regressions revealed that the percentages of patients undergoing a revascularization procedure (B = -0.022; p = .041) and cardiorespiratory fitness at baseline (B = -0.103; p = .025) were inversely related to the MCT-induced effect on the VO2peak.

Postural control quantification in minimally and moderately impaired persons with multiple sclerosis: The reliability of a posturographic test and its relationships with functional ability.

BACKGROUND: Postural control has been associated with the functional impairment in persons with multiple sclerosis (pwMS). However, there is a need for reliable methods to assess postural control in early stages of the disease, when subtle changes can be difficult to detect. The aims of this study were to assess the absolute and relative reliability of a standing and a sitting posturographic protocol in minimally (Expanded Disability Status Scale ≤ 2) and moderately (2.5 ≤ Expanded Disability Status Scale ≤ 4) impaired pwMS, and to analyze relationships among postural control and functional mobility and gait performance. METHODS: To assess postural control in an upright stance, 14 minimally and 16 moderately impaired pwMS performed six 70 s trials in tandem stance, 3 with their weaker leg behind (TSWL) and 3 with their stronger leg behind (TSSL). Additionally, participants completed five 70 s trials using an unstable sitting protocol (US) to assess trunk stability. The mean radial errors of TSWL, TSSL, and US trials were calculated as postural control indexes. Furthermore, participants performed the Timed Up and Go test (TUG) and the Timed 25-foot Walk test (T25FW) to measure their functional mobility and gait speed, respectively. Reliability was evaluated using the intraclass correlation coefficient (ICC3,1) and the standard error of measurement (SEM). Analyses of variances were carried out to assess between-group differences. Hedges' g index (dg) was used to estimate the effect size of differences. Pearson correlation analyses (r) were performed to examine the relationships among the postural control and the functional tests. RESULTS: Posturographic tests showed a high reliability in both minimally (0.87 ≤ ICC ≤ 0.92; 9.32% ≤ SEM ≤ 11.76%) and moderately (0.80 ≤ ICC ≤ 0.92; 10.33% ≤ SEM ≤ 15.33%) impaired pwMS. Similarly, T25FW and TUG displayed a high consistency in minimally (0.89 ≤ ICC ≤ 0.94; 3.43% ≤ SEM ≤ 5.17%) and moderately (0.85 ≤ ICC ≤ 0.93; 5.57% ≤ SEM ≤ 6.56%) impaired individuals. Minimally impaired pwMS showed a better performance on the TUG, T25FW, and TSWL than moderately impaired individuals (p < 0.05; dg ≥ 0.8). The TSWL, TSSL, and US variables correlated with TUG scores (0.419 ≤ r ≤ 0.604; p < 0.05), but TSWL also correlated with T25FW scores (r = 0.53; p < 0.01). Furthermore, US scores correlated with both tandem stance parameters (TSWL: r = 0.54, p < 0.01; TSSL: r = 0.43, p < 0.05). CONCLUSION: Tandem and sitting posturographic tests provide reliable measures of postural control in pwMS, even in individuals with a homogeneous disease profile. Gait speed, functional mobility, and weaker leg status seem decisive in assessing the degree of physical activity limitation in pwMS. Finally, although trunk stability does not seem to be so affected by the course of the disease, it remains relevant for postural control and functional capacity.

Isokinetic trunk flexion-extension protocol to assess trunk muscle strength and endurance: Reliability, learning effect, and sex differences.

PURPOSE: The purpose of this study was to examine the reliability and the learning effect of an isokinetic trunk flexion-extension protocol designed to simultaneously assess trunk muscle strength and endurance. In addition, the effect of the participants' sex on the reliability data was examined. METHODS: Fifty-seven healthy and physically active young men (n = 28) and women (n = 29) performed the isokinetic protocol 5 times, separated by a week between each of the first 4 sessions and by a month between the last 2 sessions. The protocol consisted of performing 4 trials of 15 maximum flexion-extension concentric exertions at 120°/s (range of trunk motion = 50°). The absolute and relative peak torque and total work were calculated to assess trunk flexion and extension strength. In addition, endurance ratio, modified endurance ratio, fatigue final ratio, recovery ratio, and modified recovery ratio variables were used for the assessment of trunk muscle endurance in both directions. RESULTS: Regarding the absolute reliability, no relevant changes were found between paired-comparison sessions for most strength and endurance variables, except for total work and relative total work variables in the flexion movement in both sexes. In addition, the typical error of the isokinetic variables was lower than 10% in both males and females, and minimum detectable changes ranged from 7% to 20%, with a tendency to be higher in females and in endurance variables. The strength variables showed high-to-excellent intraclass correlation coefficients (ICCs; >0.74); however, for the endurance variables only the endurance ratio and the modified endurance ratio obtained moderate-to-high ICC values (0.57 < ICC < 0.82). In addition, the analysis of the variance reported no significant differences between consecutive pairs of sessions for most variables in both sexes. CONCLUSION: Overall, these findings provide clinicians, trainers, and researchers with a 10-min single-session protocol to perform a reliable muscle strength and endurance evaluation of trunk flexor and extensor muscles, all within the same protocol.

Do Initial Trunk Impairment, Age, Intervention Onset, and Training Volume Modulate the Effectiveness of Additional Trunk Exercise Programs after Stroke? A Systematic Review with Meta-Analyses.

The aim of this systematic review is to analyze how, after additional trunk-focused training programs (ATEP), motor recovery after a stroke is modulated by potential effect modifiers. Twenty randomized controlled studies that carried out ATEP were included. Results showed moderate-to-high effects in favor of ATEP for trunk function, balance ability, gait performance, and functional mobility. Studies with a higher initial trunk impairment obtained a higher effect on trunk function and balance; studies with older participants had a higher effect on trunk function, limit of stability, and functional mobility, but not on balance ability. Older and more affected patients were, as well, those who started the intervention earlier, which was also linked with higher effects on trunk function, balance, and gait performance. Longer ATEP found a high effect on trunk function and balance ability. The potential effect modifiers seem to be important in the modulation of the effectiveness of ATEP and should be considered in the design of rehabilitation programs. Thus, since potential effect modifiers seem to modulate ATEP effectiveness, future studies should consider them in their experimental designs to better understand their impact on stroke rehabilitation.

A Meta-Analysis of the Reliability of Four Field-Based Trunk Extension Endurance Tests.

This meta-analysis aimed to estimate the inter- and intra-tester reliability of endurance measures obtained through trunk extension field-based tests and to explore the influence of the moderators on the reliability estimates. The reliability induction rate of trunk extension endurance measures was also calculated. A systematic search was conducted using various databases, and subsequently 28 studies were selected that reported intraclass correlation coefficients for trunk extension endurance measures. Separate meta-analyses were conducted using a random-effects model. When possible, analyses of potential moderator variables were carried out. The inter-tester average reliability of the endurance measure obtained from the Biering-Sorensen test was intraclass correlation coefficient (ICC) = 0.94. The intra-session reliability estimates of the endurance measures recorded using the Biering-Sorensen test, the prone isometric chest raise test, and the prone double straight-leg test were ICC = 0.88, 0.90, and 0.86, respectively. The inter-session average reliability of the endurance measures from the Biering-Sorensen test, the prone isometric chest raise test, and the dynamic extensor endurance test were ICC = 0.88, 0.95, and 0.99, respectively. However, due to the limited evidence available, the reliability estimates of the measures obtained through the prone isometric chest raise, prone double straight-leg, and dynamic extensor endurance tests should be considered with a degree of caution. Position control instruments, tools, and familiarization session demonstrated a statistical association with the inter-session reliability of the Biering-Sorensen test. The reliability induction rate was 72.8%. Only the trunk extension endurance measure obtained through the Biering-Sorensen test presented sufficient scientific evidence in terms of reliability to justify its use for research and practical purposes.

Understanding the Deterioration of Gait, Postural Control, Lower Limb Strength and Perceived Fatigue Across the Disability Spectrum of People with Multiple Sclerosis.

Disability progression is a prominent feature of multiple sclerosis (MS). However, little is known about the extent to which physical condition parameters and perceived fatigue evolve during the disease. We analyzed how strength, balance, core stability and perceived fatigue differ among different cohorts of people with MS (PwMS) with different disability degrees and how these contribute to patients' gait speed and functional mobility. Sixty-three PwMS divided into three groups according to the "Expanded Disability Status Scale" (MS1: EDSS ≤ 1.5; MS2: 2 ≤ EDSS ≤ 3.5; MS3: 4 ≤ EDSS ≤ 6) and 22 healthy controls (HC) participated in this study. MS1 showed lower balance and hip strength compared to HC. MS2 showed lower balance, core stability, gait speed, and functional mobility than MS1. MS3 showed lower gait speed, functional mobility, balance, and knee flexion strength than MS2. No between-group differences were observed in perceived fatigue. Relative weight analysis showed that strength, balance and core stability explained 60%-70% of the variance in gait speed and functional mobility. The decline of each parameter did not evolve at the same rate across the different stages of the disease, being knee flexion strength and balance the most influential factors in the disability progression. Overall, these results provide useful information to guide exercise prescription at different stages of MS.