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.

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.

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.

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.

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.

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.

Effects of Maximal Strength Training on Perceived-Fatigue and Functional Mobility in Persons with Relapsing-Remitting Multiple Sclerosis.

Background and objectives: Fatigue is one of the most disabling symptoms that limit daily life activities in persons with multiple sclerosis (pwMS). This study aimed to evaluate the effects of maximal strength training (MST) on perceived-fatigue and functional mobility in pwMS. Materials and Methods: 26 participants with MS were balanced according to their pre-intervention fatigue scores and distributed into an MST group (n = 13) and a control group (CG; n = 13). The MST group completed eight weeks using high loads, evaluating detraining after ten weeks. Quadriceps and hamstring isokinetic (QPTIK; HPTIK) and isometric (QPTIM; HPTIM) peak torques were assessed using an isokinetic dynamometer. Effect size differences were estimated with the Hedges' g index (dg ). Fatigue was evaluated through the Fatigue Severity Scale (FSS), while functional mobility was assessed via the Timed Up and Go Test (TUG). Results: The MST significantly improved all the strength measurements after the intervention (Δ6.43-29.55%; p < 0.05) compared to the control group. FSS showed a significant reduction (59.97%, dg = 5.41, large). The MST group also reduced the TUG time (19.69%; dg = 0.93, large) compared to the control group. Improvements caused by the intervention did not remain after a 10-week follow-up, with decreases in strength performance from 4.40% to 13.86% (dg = 0.24-0.56, small to moderate), 112.08% in the FSS (dg = -3.88, large), and 16.93% in TUG (dg = -1.07, large). Conclusions: MST (up to 90% 1RM) seems to be a feasible and useful way to obtain clinically relevant improvements in the perceived-fatigue symptoms and functional mobility. Still, symptom improvements decrease after a 10-week detraining period.