Isometric Endurance Research Articles

Examining the Independent and Interactive Carryover Effects of Cognitive and Physical Exertions on Physical Performance.

This study compared the effects of prior cognitive, physical, and concurrent exertion on physical performance. Fatiguing cognitive and physical exertions have been shown to negatively affect subsequent task performance. However, it is not clearly understood if concurrent physical and cognitive effort may exaggerate the negative carryover effects on physical task performance when compared to cognitive or physical exertion alone. Twenty-five participants completed four isometric handgrip endurance trials on different days. The endurance trials were preceded by four, 15-minute experimental manipulations (cognitive, physical, concurrent, control). Electromyography (EMG) and force tracing performance were monitored, with handgrip strength measured pre and post. Subjective ratings of mental and physical fatigue, as well as affect, motivation, and task self-efficacy, were also assessed. Handgrip strength decreased following both physical (-14.4% MVC) and concurrent (-12.3% MVC) exertion manipulations, with no changes being observed for the cognitive and control conditions. No differences were observed across conditions for endurance time, EMG, nor tracing performance. When compared to the control conditions, perceptions of mental and physical fatigue were higher following the experimental manipulation. Endurance trial self-efficacy was lower for the mental, physical and concurrent conditions compared to control. The concurrent condition resulted in similar decreases in strength as the physical fatigue condition, but otherwise resulted in similar carryover effects on endurance performance across all conditions. Further study is required at higher exposure levels, or for longer exposure durations, to further probe the influence of concurrent physical and cognitive effort on task performance. Concurrent cognitive and physical effort resulted in similar physical performance decrements to physical effort alone.

Tongue and Lip Strength and Endurance in Healthy Young Adults With and Without Orofacial MyofunctionalDisorders.

Based on the premise that tongue and lip force is affected in individuals with orofacial myofunctional disorders (OMDs), orofacial myofunctional therapy (OMT) programs typically include the strengthening of orofacial muscles through isometric and isotonic exercises. The purpose of this study is to examine whether there is indeed a measurable difference in maximum tongue and lip strength and endurance between subjects with and without OMDs, as well as to explore Oral Health-Related Quality of Life (OHRQoL) in this population. Sixty healthy young adults (mean age 18.9 years, SD 0.69 years, range 18.0-21.4 years) participated in this study. Perceptual evaluation of orofacial functions was conducted using the Orofacial Myofunctional Evaluation with Scores (OMES) protocol. Participants were divided into three groups, namely those with physiological orofacial functions (POF; n = 20), those with inconsistent orofacial functions (IOF; n = 11), and those with consistent OMDs (OMD; n = 29). Maximum isometric pressure and endurance of tongue and lips were measured using the Iowa Oral Performance Instrument (IOPI). OHRQoL was assessed using the Oral Health Impact Profile (OHIP-14). The OMES total scores did not differ significantly between the three groups, though the subscale 'function' showed significant differences (13.637; p = 0.001). No statistically significant differences in maximum isometric pressure or endurance for tongue and lips, nor for OHIP scores, were measured between the three groups. Although orofacial muscle strengthening is commonly part of OMT, current findings suggest the superfluity of these types of exercises in the treatment of OMDs in healthy young adults and may indicate the need to focus on awareness and rehabilitation of pathological functions in these individuals. Re-evaluation of the efficacy of OMT programs in different populations may be an important strategy going forward.

Relationship between paraspinal muscle morphology and function in different directions in a healthy Chinese population at different ages: a cross-sectional study

BackgroundParaspinal muscle degeneration occurs with age; however, it is unknown whether strength and endurance change with muscle cross-sectional area (CSA) and fatty infiltration (FI) parameters in Chinese healthy individuals.MethodsA total of 94 asymptomatic Chinese volunteers were enrolled in this study. The participants were divided into three groups: young (20–39 years old, n = 27), middle-aged (40–59 years old, n = 49), and elderly (≥ 60 years old, n = 18). CSA and FI of the psoas (PS), quadratus lumborum (QL), multifidus (MF), and erector spinae (ES) were measured using magnetic resonance imaging. The Bionix Sim3 Pro was used to evaluate the maximum isometric torque and the Ito test to evaluate endurance.ResultsThe CSA of the PS and ES in the elderly group was smaller than those in the other groups, while the CSA of QL in the young group was larger than that in the other groups. There were differences in the MF and ES FI among the three groups. The maximum isometric torque and endurance test time decreased with increasing age; however, these differences were not statistically significant. Maximum isometric torque positively correlated with the average paraspinal muscle CSA and negatively correlated with the torque and FI of the MF and ES muscles. The endurance test was found to be positively correlated with the FCSA of the MF and to be negatively correlated with the FI of the MF and ES. PS and QL can predict the maximum isometric torque, and MF and PS can predict the endurance time.ConclusionMF and ES showed earlier degeneration than PS and QL. MF is the first paraspinal muscle to undergo functional area atrophy, and it plays an important role in the endurance test. The maximum moment of equal length in all directions of the lumbar spine is not completely symmetrical, but it is correlated with the imaging parameters of the paraspinal muscles. QL and PS were more activated in the lumbar activity.Trial registrationThe study was registered in Chinese Clinical Trial Registry and the registration number is ChiCTR2000039073 on 15/10/2020 (https://www.chictr.org.cn/showproj.html?proj=62785). Ethical Approval was obtained from the Peking University Third Hospital Medical Science Research Ethics Committee (IRB00006761-M2020305).

Impact of short-term functional training program on lower-body isometric muscle endurance in cricket players

Impact of short-term functional training program on lower-body isometric muscle endurance in cricket players

Isometric Fatigue Resistance of Lumbar Extensors and Cardiovascular Strain in Lower Back Pain Patients Are Associated with Angiotensin-Converting Enzyme and Tenascin-C Gene Polymorphisms

Background: We tested whether gene polymorphisms for angiotensin-converting enzyme (ACE, rs1799752) and tenascin-C (TNC, rs2104772) are associated with variability in fatigue resistance and metabolic strain during static lumbar exercise through interactions with chronic nonspecific lower back pain and habitual physical exercise levels (PA). Methods: Forty-eight patients and matched controls performed an isometric endurance test for lumbar extensors. Metabolic strain to longissimus muscle (oxygen saturation, lactate) and cardiovascular system (muscle hemoglobin, blood pressure) and holding time were monitored. Subjects were genotyped for rs1799752 (II, ID, DD) and rs2104772 (AA, AT, TT). Associations of variance with group, genotype, and PA were analyzed under a 5% false discovery rate. Results: The holding time was lower in patients than in controls (150.9 vs. 188.6 s). This difference was associated with both genotypes, as patients with DD-rs1799752-genotype (p = 0.007) and TT-rs2104772-genotype (p = 0.041) showed lower fatigue resistance. Muscle deoxygenation during exercise varied in positive association with the rs2104772-genotype and PA (p = 0.010, η2 = 0.236). Mean arterial blood pressure (p = 0.028, η2 = 0.108) and recovery of hemoglobin concentration (p = 0.003, η2 = 0.907) demonstrated complex group x rs2104772 interactions. Conclusions: Polymorphisms rs1799752 and rs2104772 influence back pain-related variability in lumbar fatigue resistance. rs2104772 was linked to cardiovascular strain during isometric exercise and recovery via muscle perfusion.

Acute effects of whole-body vibration on unilateral isometric knee extensors maximal torque and fatigability during an intermittent endurance task in adult males

Whole-body vibration (WBV) has been employed for performance-enhancing purposes. WBV may positively affect muscular endurance and its underlying neural mechanisms due to an enhanced muscular blood circulation and oxygen uptake. However, the effects of WBV on endurance-related torque signal complexity have been understudied. This study aims to investigate the acute effects of WBV on i) maximal isometric torque production; ii) isometric knee extensors fatigability and iii) torque signal complexity during an isometric endurance task.Thirty adult males performed an isometric intermittent endurance protocol on their dominant lower limb after performing: static half squat with WBV (WBV), static half squat without WBV (HS), and no exercise protocol (CC). For each repetition the maximal torque was identified. The maximal torque of the first repetition was identified as the PeakT. The Mean torque (MTorque) and fatigue index (pFatigue) were calculated as the mean and the percentage decay in torque across the entire set of eighteen repetitions (MTorque0–100 %, pFatigue0–100 %), and across shorter blocks of six repetitions (MTorque0–33 %, pFatigue0–33 %; MTorque34–66 %, pFatigue34–66 %, and MTorque67–100 %, pFatigue67–100 %). Torque fluctuations were analysed computing Sample Entropy (SampEn) and the coefficient of variation (CV).PeakT was significantly higher in CC than in WBV (p < 0.01) and in HS (p < 0.01). PeakT was significantly higher in HS than in WB (p < 0.05). MTorque0–100 %, MTorque0–33 %, MTorque34–66 %, and MTorque67–100 % were significantly higher in CC than in WBV (all p-values <0.01) and in HS (p < 0.01). MTorque67–100 % was significantly higher in HS than in WB (p = 0.049). pFatigue34–66 % was significantly higher in WBV than in CC (p < 0.05) whereas pFatigue67–100 % was significantly higher in CC than in WB (p < 0.01) and in HS (p < 0.01). No effect of condition was observed for SampEn and CV.Acute WBV does not lead to beneficial effects on maximal torque production and isometric knee extensors fatigability. These acute detrimental effects may be related to long-term WBV-related adaptations.

Criterion (Concurrent) Validity and Clinical Utility of the Tongueometer Device.

Tongue manometry (i.e., tongue pressure measurement) is a commonly used assessment for patients with suspected oral-motor involvement in swallowing disorders. Availability of lingual manometry has changed in recent years, with the introduction of the Tongueometer device being a more affordable tongue manometry system. The purpose of this study was to test concurrent (criterion) validity of the Tongueometer compared to the current standard reference device, the Iowa Oral Performance Instrument (IOPI). Adults without dysphagia were recruited for participation in this study. Standard lingual measurements (swallowing-related pressures, maximum isometric pressure [MIP], and maximum isometric endurance) were recorded, with the bulb anteriorly placed, with both devices, in a randomized order. The Bland-Altman method was used to determine concurrent (criterion) validity of these measurements compared to the clinical standard IOPI device. A recently available suggested corrective value by Curtis et al. (2023) was also applied, with comparisons made between devices both with and without the Curtis correction. The final sample included 70 adult participants aged 20-89 years (Mage = 52.3 years). Measures with the Tongueometer device were significantly lower when compared with the same measures taken using the IOPI (p < .01) for all measures including MIP, endurance, and swallow pressures. The correction suggested by Curtis and colleagues did not ameliorate these differences. The Tongueometer lingual measurements were consistently lower compared to the IOPI. Clinical use of values taken with the Tongueometer device should be compared to normative data published for each specific device. Available features of each device (e.g., display, bulb texture, technology/application) should be considered when selecting which device to use with an individual patient.

Reliability in Novel Field-Based Fitness Measurements and Postexercise Scores from a Physical Fitness Test Battery in Older Adults

Introduction: Physical fitness is strongly associated with daily physical function, health, and longevity in older adults. Field-based tests may provide a reasonable alternative compared to advanced laboratory testing. Separating postexercise test scores from reactivity measurements requires sufficient test-retest reliability. Postexercise test scores with reliability analyses of field-based fitness tests in older adults are lacking. The present study aimed to examine the test-retest reliability of some novel easily accommodated fitness test measurements and compare pretest scores with postexercise results in these tests along with other field-based fitness tests in older adults. Methods: Totally 1,407 community-dwelling older adults (69% female), x̄ = 71.5 ± 5.0 (65–84 years), performed twelve field-based fitness tests at pretest 1, pretest 2 and a posttest after an 8-week exercise period (twice weekly 1 h of combined strength and aerobic training). T tests, intra-class correlation, limits of agreement, standard error of measurement, and coefficient of variance were performed between pre-1 and pre-2 tests, and repeated measures ANOVA and partial eta squared effect size for postexercise differences for men and women in 5-year age groups ranging from 65 to 84 years. Results: Between pre-1 and pre-2 tests a significant difference was noted in some of the novel fitness test measurements but generally not, e.g., in isometric trunk flexion and step-up height on either leg among all sex and age groups. In most of these novel fitness test measurements, no significant differences occurred between the two pretests. Examples of results from the pre-2 test to the posttest were isometric trunk flexion 45° endurance and isometric trunk extension endurance improved significantly for both sexes in age groups 65–74 years. Women, but not men, improved the maximal step-up height for both legs in most age groups. The speed in the 50 sit-to-stand improved significantly for most age groups in both sexes. Six-min walk distance improved significantly for most age groups in women but among men only in 65–69 years. In the timed-up-and-go test, significant improvements were seen for all age groups in women and in men 70–79 years. No postexercise improvements were generally observed for grip strength or balance. Conclusions: In most of the novel fitness test measures, no significant difference was noted between the two pretests in the assessed sex and age groups. Results after the 8-week exercise period varied between sex and age groups, with significant improvements in several of the twelve studied fitness tests. These findings may be valuable for future projects utilizing easily accommodated physical fitness tests in older adults.

Motor alterations along the kinetic chain in amateur volleyball and handball athletes with shoulder pain: An observational comparative study

Overhead sports overload the shoulder complex due to movement repetition and the great amount of force created during the athletic motion, which may cause adaptations in the shoulder and lead to shoulder pain. However, overhead movements include the kinetic chain, and alterations in some of the structures throughout the kinetic chain may increase stress on the shoulder complex and be associated with shoulder pain. PurposeTo compare kinetic chain components in overhead athletes with and without shoulder pain. MethodsForty-one volleyball and handball athletes (21 with and 20 without shoulder pain) were included and assessed for hip internal (IR) and external rotation (ER) range of motion (ROM), hip and trunk isometric strength, trunk endurance and neuromuscular control of the lower and upper limbs (Y balance test). ResultsAthletes with shoulder pain showed smaller IR ROM in both hips, lower endurance time for trunk extensors and flexors, decreased reach distance in the anterior and posteromedial direction, as well as a smaller composite score in the Y balance test (p < 0.05). ConclusionVolleyball and handball athletes with shoulder pain showed changes in ROM throughout the kinetic chain in addition to lower core endurance, and decreased neuromuscular control of lower limbs.

A Profile of Isometric Cervical Strength in Elite Professional Male Rugby Players.

OBJECTIVES: To (1) provide position-specific normative data for isometric cervical muscle strength and endurance in professional, male rugby players and (2) assess the relationship between age, height, weight, and playing position with cervical muscle strength and endurance. DESIGN: Cross-sectional study. METHODS: Professional rugby players completed peak isometric cervical strength testing followed by a test of cervical muscle endurance. Descriptive statistics for continuous variables with strength normalized to body weight were performed. Multiple linear regression was used to estimate associations between strength measurements. RESULTS: In total, 136 players participated including front-row forwards (27%), other forwards (28%), and backs (45%). Front-row forwards had significantly greater peak isometric cervical muscle strength than other position groups, with backs having the lowest strength. Extension produced the highest force for all 3 position groups (429 N ± 104 N), whereas flexion produced the least (275 N ± 65 N). Age was associated with increased isometric cervical muscle strength. There was a statistically significant relationship between peak flexion strength and flexion endurance (P = .003). The average time for the endurance tests were 55.7 (±17.1) seconds and 52.9 (±20.1) seconds for extension and flexion, respectively. Other forwards had lower cervical extension muscle endurance than backs and front-row forwards. CONCLUSIONS: Normative values for peak and endurance isometric strength in professional rugby players illustrate significant differences between playing position. Consider age, body weight, and intraindividual variability when interpreting cervical strength and endurance results. J Orthop Sports Phys Ther 2024;54(3):1-8. Epub 29 January 2024. doi:10.2519/jospt.2024.11830.

Acute Effects of Combining Whole-Body Electromyostimulation with Resistance Training in Active Women.

Strength training elicits benefits both in performance and on a psychological level in women, such as increased muscle strength and improved self-esteem. Whole-body electromyostimulation (WB-EMS) could be a training strategy for enhancing muscular strength. The aim of this study was to assess the acute effects of a single session of WB-EMS superimposed over classic resistance training on isometric strength, endurance strength and flexibility. Furthermore, the safety of the protocol was assessed by monitoring the levels of creatine kinase (CK) 48 h after the training protocol was completed. Sixteen active women (aged 22.06 ± 1.88) were randomly assigned to an experimental group (EG) (n = 8) and a control group (CG) (n = 8). The EG performed four sets of 12 repetitions of three strength exercises with superimposed WB-EMS, while the CG performed the same protocol without WB-EMS. RM-ANOVA showed a significant time*group interaction on posterior kinetic chain extensors' mean and peak strength in the EG (F(1,14) = 10.036; p = 0.007; and F(1,14) = 20.719; p < 0.001; respectively). A significant time*group interaction was found in the sit and reach test for the EG (F(1,14) = 10.362; p = 0.006). Finally, ANOVA performed on the CK levels showed no significant difference between the groups (F(1,14) = 0.715; p = 0.412). WB-EMS training led to an immediate improvement in strength performance and flexibility, and this protocol was shown to be safe in terms of CK levels, 48 h after completing the training protocol.

The Effect Of Automated Component Impaction On The Surgeon’s Ergonomics, Fatigue And Stress Levels In Total Hip Arthroplasty

Background Total Hip Arthroplasty (THA) surgery is physically and cognitively challenging. Sub-optimal posture during component impaction may influence surgeon’s ergonomics and fatigue. Methods Thirty THA procedures were executed for 3 days. Only during the first day, manual impaction (MI) was performed. Postural risk was evaluated with Rapid Upper Limb Assessment (RULA) and Rapid Entire Body Assessment (REBA) score. Three cognitive tasks (Simon, pattern comparison and pursuit rotor test) and five physical tests (isometric wall-sit, plank-to-fatigue, handgrip, supra-postural task, and shoulder endurance) assessed surgeon’s psycho-physiological load in the morning, midday, and afternoon. Surgeon’s cortisol concentration and sound level of the broaching process was also recorded. Results RULA and REBA scores were 1.7 to 3 times lower with automated impaction (AI). Physical exhaustion was lower with AI: isometric wall-sit test (10.6% vs. 22.9%), plank-to-fatigue (2.2% vs. 43.8%), supra-postural task (-0.7% vs. -7.7%), handgrip force production (dominant hand -6.7% vs. -12.7%; contralateral +4.7% vs. +7.7%), and in shoulder endurance (-15s vs. -56s). After AI, the cognitive performance showed faster response times and lower error rates for all cognitive tests compared to MI. The salivary cortisol level decreased during the AI-days by 51% in comparison to a 38% increase following the MI-day. Mean broaching time with AI was 7’3’’ compared to 6’20’’ with MI. The mean sound level with the AI-device was 64.3 dBA compared to 68.2 dBA with manual impaction. Conclusions Automated THA component impaction improved the surgeon’s ergonomics which resulted in reduced hormonal stress levels and lower physical and cognitive exhaustion.

Can photobiomodulation improve quadriceps strength and endurance outcomes in asymptomatic adults? A double-blind randomized controlled trial

AimTo explore the effect of photobiomodulation on quadriceps strength and endurance torques in asymptomatic adults. MethodsTwenty-eight asymptomatic adults were randomized to one of two interventions: photobiomodulation (n = 14) or sham (n = 14). Quadriceps strength was evaluated by maximum voluntary isometric contraction test (60°) and endurance by an elastic resistance in multiple-set knee extension/flexion repetitions using a traction dynamometer. The outcomes were measured at three time points: pre-baseline; baseline and; final assessment. The photobiomodulation was applied to the quadriceps and triceps surae muscles of each participant's dominant lower limb, using a cluster with 1 infrared laser diode and 3 led amber of 170 mW for 240 s over four consecutive days. The sham group went through the same procedures, but the equipment was off, and patients and assessors were blinded to the intervention. Reliability and minimal detectable change of the measures were obtained from the pre-baseline and baseline time points. Differences between interventions were tested by an analysis of covariance. Results and discussionThere was no difference between photobiomodulation compared to sham in maximum isometric torque (mean difference (95% CI) = 0.008 (−0.29 to 0.31) and endurance torques (mean difference (95% CI) = 0.04 (−0.03 to 0.12). The mean difference was lower than the minimal detectable change for the maximum isometric torque (1.02 Nm.kg−1) and endurance torque (0.49 Nm.kg−1). ConclusionPhotobiomodulation does not improve quadriceps strength and endurance outcomes in asymptomatic adults.

Fatigue task-dependent effect on spatial distribution of lumbar muscles activity

This study aims to identify how spatial distribution of lumbar muscle activity is modulated by different fatigue tasks. Twenty healthy adults performed two different isometric trunk extension endurance tasks (the modified Sorensen test and the inverted modified Sorensen test) until exhaustion. During these tasks, bilateral superficial lumbar muscle activity was recorded using high-density electromyography. The spatial distribution of activation within these muscles was obtained using the centroid coordinates in the medio-lateral and cranio-caudal directions. The effects of task and endurance time (left and right sides) were investigated using repeated measures ANOVA. Results revealed a significant lateral shift of the centroid throughout the fatigue tasks on both sides and no difference between tasks. Significant task × time interaction effects were found for the cranio-caudal direction on both sides showing a significantly more caudal location of the centroid in the modified Sorensen test compared to the inverted test at the beginning of the tasks. Our findings suggest that spatial distribution of lumbar muscle activity is task-dependent in a pre-fatigue stage while an alternative but similar muscle recruitment strategy is used in both tasks to maintain performance in the later stages of muscle fatigue.

The Effect of a Novel Weight-Supported Kinetic Chain Resistance Training Program on Proximal Core Muscular Endurance, Trunk-to-Arm Muscular Power, and Bat Swing Speed.

Palmer, TG, and McCabe, M. The effect of a novel weight-supported kinetic chain resistance training program on proximal core muscular endurance, trunk-to-arm muscular power, and bat swing speed. J Strength Cond Res 37(11): 2130-2140, 2023-Muscular stability and muscular power at the proximal core segments of the pelvis, spine, and trunk are essential attributes in maximizing bat swing speed in the sport of softball. Weight-supported kinetic chain resistance training (WsKC) is a novel closed kinetic chain technique that provides synergistic multiplanar stressors to the proximal core segments via the lower and upper extremities while limiting joint compression and sheer forces throughout the kinetic chain. The aim of this study was to assess the effect a 7-week preseason WsKC program would have on an isometric muscular endurance plank, trunk-to-arm peak muscular power (TAPP), trunk-to-arm peak velocity (TAPV), and bat swing speed (BSS) compared with a traditional isotonic weight resistance training program. Twenty-seven female high school softball players (age = 16 years, height = 167.6 cm, body mass = 62.86 kg) were assigned in a blocked randomization to one of 2 groups: a standing weight-supported kinetic chain resistance training (WsT) group (n = 13) or a pseudo-control traditional isotonic training (TT) group (n = 14). The WsT group had significant improvements (p < 0.05) for the isometric endurance plank (p = 0.001), TAPP (p = 0.002), TAPV (p = 0.001), and BSS (p = 0.02) compared with the TT group. The training effect size (ES) was large for the WsT group for all variables (ES = 1.0-7.4) and small to moderate for a majority of the TT variables (ES = 0.06-0.47). The simultaneous improvement in the isometric endurance plank, trunk-to-arm rotations, and BSS indicates that the WsKC contributed to subsequent improvements in BSS in high school softball players.

Multi joint short term resistance training strength zone evaluated on maximal strength, maximal ısometric strength, peak isom reach, maximal isometric endurance and muscular local endurance in resistance trained men

To resistance trained men multi joint short term strength zone periodization for strength training non-periodic progression producted by performing peak isom reach periodize model on maximal strength and maximal isometric strength for peak isom reach periodize model for strength development on isometric strength. Other maximal isometric endurance and muscular local endurance were provided on load-time curve intensity in muscular isom change load intensity. In this case, determination on strength zone periodization was performed on 1-5RM strength zone one session set-up and maximal isometric strength on load-time curve at peak isom reach development. The peak isom reach for periodic strength sessions were conducted on strength/speed at 80% of 1RM (2.5 s) and maximal strength/force at 90% of 1RM (4 s) on maximal isometric strength. Indeed, multi joint strength zones developed the maximal squat (ES=0.55; p=0.000; t=-4.837), bench press (ES=0.46; p=0.000; t=7.386) and deadlift (ES=0.50; p=0.000; t=-4.837) in resistance trained men. This study were noted to peak isom reach periodize model performance developed on multi joint load repetition may be use for maximize performance in continuum repetition zone..

Role of the Paraspinal Muscles in the Sagittal Imbalance Cascade: The Effects of Their Endurance and of Their Morphology on Sagittal Spinopelvic Alignment.

The role of paraspinal muscle degeneration in the cascade of sagittal imbalance is still unclear. This study aimed to compare paraspinal muscle degeneration in the 4 stages of sagittal imbalance: sagittal balance (SB), compensated sagittal balance (CSB), decompensated sagittal imbalance (DSI), and sagittal imbalance with failure of pelvic compensation (SI-FPC). In addition, it aimed to compare the effects paraspinal muscle endurance and morphology on sagittal spinopelvic alignment in patients with lumbar spinal stenosis. A cross-sectional study of 219 patients hospitalized with lumbar spinal stenosis was performed. The isometric paraspinal extensor endurance test and evaluation of atrophy and fat infiltration of the paraspinal extensor muscles and psoas major on magnetic resonance imaging were performed at baseline. Spinopelvic parameters including lumbar lordosis, pelvic tilt, sacral slope, pelvic incidence, and the sagittal vertical axis were measured. The patients with lumbar spinal stenosis were divided into 67 with SB, 85 with CSB, 49 with DSI, and 17 with SI-FPC. There were significant differences in paraspinal muscle endurance and morphology among the 4 groups. Furthermore, the SI-FPC group had poorer paraspinal muscle endurance than either the SB or the CSB group. In multiple linear regression analysis, paraspinal muscle endurance and the relative functional cross-sectional area of the paraspinal extensor muscles were the independent predictors of the sagittal vertical axis, and the relative functional cross-sectional area of the psoas major was the independent predictor of relative pelvic version. This study indicated that paraspinal muscle degeneration is not only an initiating factor in pelvic retroversion but also a risk factor for progression from a compensated to a decompensated stage. Specifically, the impairment of muscle endurance in the CSB stage may be the reason why patients experience failure of pelvic compensation. In addition, paraspinal muscle endurance and muscle morphology (relative functional cross-sectional area of the paraspinal extensor muscles and psoas major) had different clinical consequences. Prognostic Level II . See Instructions for Authors for a complete description of levels of evidence.

Electrical dry needling versus a non-invasive multicomponent intervention in the treatment of myofascial trigger points in patients with chronic low back pain: A randomised clinical trial

Objective To compare the effects of electrical dry needling with a non-invasive multi-component intervention in patients with chronic low back pain. Design A randomised single-blind clinical trial. Setting Outpatient Physiotherapy Clinic; home. Participants Sixty-four patients with chronic low back pain aged 30–65 years. Interventions Six-week electrical dry needling on myofascial trigger points, and a non-invasive multicomponent intervention (home exercise programme, stretching and ischemic compression). Main measures Pain (Visual Analogue Scale), disability (Roland-Morris Disability Questionnaire and Oswestry Disability Index), kinesiophobia (Tampa Scale of Kinesiophobia), quality of life and sleep (Short Form 36-item Health Survey and Pittsburgh Sleep Quality Index), isometric endurance of trunk flexor muscles (McQuade test), lumbar mobility in flexion (finger-to-floor distance), and pressure pain threshold (algometer) were assessed at baseline, after 6 weeks, and after 2 months. Results ANOVA showed statistically significant differences in group-by-time interaction for most pain pressure thresholds of myofascial trigger points (P < 0.05), for disability (Roland-Morris Disability Questionnaire: F = 6.14, P = 0.016; and Oswestry Disability Index: F = 7.36, P = 0.009), for trunk anteflexion (F = 10.03, P = 0.002) and for habitual sleep efficacy (F = 6.65, P = 0.012), use of hypnotics (F = 4.77, P = 0.033) and total score of quality of sleep (F = 8.23, P = 0.006). Conclusions In comparison to a non-invasive multicomponent intervention, electrical dry needling has more positive effects on disability, pain intensity, kinesiophobia, and reducing patients’ sensitivity to myofascial trigger points pressure, at post-treatment and at 2 months. Clinical Trial Registration number NCT04804228. Registered on May 28th, 2021. Available at https://clinicaltrials.gov/ct2/show/NCT04804228

Transient Change in Core Strength, Endurance, and Upper Limb Isometric Strength After Core Stabilisation Knockdown Protocol in Female Athletes

Objectives: We assessed the effect of change in core isometric strength and endurance on upper limb isometric strength in female athletes. Methods: In this experimental study, 32 female athletes aged 18-25 years were recruited based on the inclusion criteria. (17 cases in the experimental group and 15 cases in the control group). Before and after the core stabilization knockdown protocol, participants were assessed for isometric core strength (abdomen/back rehab 5310; rehab line), core endurance (curl-up test), and upper limb isometric strength (push up/pull down rehab 5120; rehab line). Results: The results showed a significant reduction in abdomen, back, push-up, pull-down isometric strength, and curl-up test scores in the experimental group and no significant differences in these parameters in the control group after the protocol. The experimental and control groups showed significant differences in the aforementioned parameters after the protocol. Discussion: This research suggests that performing extensive and exclusive core exercises to relieve fatigue prior to upper limb training can decrease the potential for core activation. This can ultimately lead to reduced effectiveness of upper extremity exercises or rehabilitation sessions, which can lead to upper body injuries. These exercises can be useful to enhance the knowledge regarding the sequencing of core and upper limb exercises in an athlete’s training protocols.

Isometric tongue endurance and incomplete laryngeal vestibule closure in Parkinson's disease.

Dysphagia is a common symptom of Parkinson's disease (PD). A delay in laryngeal vestibule closure (LVC) and a reduction in tongue pressure, may affect swallowing safety and increase the risk of pulmonary aspiration. To verify the relationship between tongue pressure and airway protection in PD patients: (1) comparing tongue pressure measures and physiological events in the pharyngeal phase of swallowing between PD and controls and (2) analysing the association between tongue pressure and LVC in the PD group. Twenty-three patients with idiopathic PD (64.9 years) and 24 healthy controls (64.1 years) participated in this study. All participants underwent the following procedures to verify tongue pressure measurements using the Iowa Oral Performance Instrument: maximum anterior and posterior pressure, isotonic and isometric tongue endurance and anterior and posterior tongue pressure during saliva swallowing. To verify swallowing safety, videofluoroscopic swallowing studies focusing on the pharyngeal phase were performed based on the MBSImP protocol. Compared to healthy controls, PD exhibited a statistically significant decline in tongue pressure tasks: posterior maximum pressure, isotonic endurance, anterior and posterior isometric endurance and tongue pressure during posterior swallowing. Patients with PD had worse pharyngeal scores, including LVC scores, than controls. PD and incomplete LVC had lower anterior isometric endurance scores when compared to those with complete LVC. PD with incomplete LVC scored lower in the anterior isometric endurance task. We observed a potential clinical use of this task for the assessment and management of dysphagia in patients with PD.