Muscle Strength Parameters Research Articles

An observational study of lower limb muscle imbalance assessment and gait analysis of badminton players

PurposeThe imbalance of muscle strength indicators has a negative impact on players. Lower limb muscle imbalance can cause gait abnormalities and increase the risk of muscle injury or decreased performance in significantly asymmetrical situations. This study aims to assess the lower limb muscle imbalance and gait feature between the dominant and non-dominant sides of badminton players and the associations between the two variables.MethodsThe study included 15 badminton players with years of training experience. Muscle strength and gait parameters were obtained from isokinetic muscle strength testing and plantar pressure analysis systems. The symmetry index was calculated based on formulas such as plantar pressure distribution and percentage of plantar contact area.ResultsIn the isokinetic muscle strength test, significant differences were found in bilateral knee flexors’ average power and total work at 60°/s angular speed. The hamstring to quadriceps ratio (H/Q) range of knee joints of the dominant and non-dominant sides is 0.63–0.74 at low speed, while the H/Q range is 0.81–0.88 at fast speed. The H/Q of bilateral knees increases with increasing angular velocity. As the angular velocity increases, the peak torque to body weight ratio (PT/BW) of the participants’ bilateral knee flexors and extensors shows a decreasing trend. The asymmetry score of H/Q at 180°/s angular speed is positively related with step time and stance time. There are varying degrees of differences in gait staging parameters, plantar pressure in each area, plantar contact area, and symmetry index between the dominant and non-dominant sides of badminton players when walking.ConclusionBadminton players have weaker flexors of the knee joint, imbalanced muscle strength in flexors and extensors, decreased lower limb stability, and a risk of knee joint injury on the non-dominant side. The bending and stretching strength of the knee joint on the dominant side of the players is greater than that on the non-dominant side. The pressure in the first metatarsal region of the dominant side is higher, while that in the midfoot and heel regions is higher on the non-dominant side. badminton players have better forward foot force and heel cushioning ability. Long term badminton sports result in specialized changes in plantar pressure distribution and reduced symmetry.

Skeletal and respiratory muscle weakness contributes to decreased exercise capacity in hypertrophic cardiomyopathy

Abstract Background and Aims Although decreased exercise capacity (due to dyspnea or angina-like symptoms) constitutes the fundamental characteristics of hypertrophic cardiomyopathy (HCM), the pathophysiology of these symptoms remains only partly understood. We investigated clinical and functional determinants of decreased exercise capacity in a broad range of HCM patients irrespective of primary disease aetiology (either genetic disorder or e.g. infiltrative phenocopies in the course of cardiac amyloidosis), overt heart failure (HF) and the presence of haemodynamically significant left ventricular outflow tract obstruction (LVOTO). Further, we deterimined the contribution of skeletal and respiratory muscle weakness to decresed exercise capacity. Methods We analyzed clinical data and functional assessments (skeletal and respiratory muscle strength, physical fitness) in relation to symptomatology and sub-maximal exercise capacity in 82 clinically stable patients with HCM (females: 32 %; age: 62±16 years; left ventricular ejection fraction [LVEF] 59±7%; intraventricular septum wall thickness [IVS] 19±4 mm; median plasma N-terminal pro-B-type natriuretic peptide [NT-proBNP]: 818 pg/mL [lower and upper quartile: 208-1917]; New York Heart Association [NYHA] class 0/I/II/III: 38/18/33/11 % [0 indicates no HF]; significant LVOTO: 29%). Results HCM patients with more severe symptomatology (NYHA class II-III vs 0-I) were older, had more frequently significant LVOTO and greater comorbidity burden, and had higher NT-proBNP and worse estimated renal function (all p≤0.03). Gender distribution, percentage of beta-blocker therapy and implanted device, body mass index, major echocardiography parameters (including LVEF, left ventricular end-diastolic diameter and IVS), high-sensitive (hs) cardiac troponin type I and hs-C-reactive protein were comparable in these 2 groups of subjects (all p>0.05). In multivariable linear regression models more advanced age, higher circulating natriuretic peptides (NT-proBNP) and previous coronary revascularization were independent predictors of more advanced NYHA class (standardized β-coefficient=0.30, p<0.01; β=0.27, p<0.01; and β=0.22, p<0.05; respectively). Similarly, more advanced age, female sex and higher NT-proBNP were independent correlates of shorter distance in 6-minute walking test (6MWT) (β=-0.46, p<0.001; β=-0.26, p<0.001; and β=-0.36, p<0.001; respectively). All analyzed muscle parameters (including respiratory muscle strength parameters) and objective measures of physical fitness (Functional Fitness Test for older adults) remained independently associated with 6MWT distance (all p<0.001) when adjusted for aforementioned clinical and laboratory correlates of 6MWT. Conclusions Muscle weakness and low physical fitness are related to decreased exercise capacity in HCM and may be potential therapeutic targets to alleviate disease symptoms also in non-obstructive HCM phenotype.

6427 Impact of Adrenalectomy On Frailty And Muscle Function In Patients With Mild Autonomous Cortisol Secretion: A Prospective Longitudinal Study

Abstract Disclosure: J. Saini: None. V. Fell: None. B. Atkinson: None. S. Achenbach: None. I. Bancos: None. Background: Patients with mild autonomous cortisol secretion (MACS) have a higher prevalence of frailty and reduced muscle strength as compared to patients with nonfunctioning adrenal adenomas or subjects without adrenal disorders. Objective: To determine the impact of adrenalectomy on frailty and parameters of functional strength in patients with MACS. Methods: We conducted a single-center prospective longitudinal study of adults with MACS scheduled for adrenalectomy and referent subjects evaluated between 2018 and 2023. MACS was defined as serum cortisol>1.8 mcg/dL after 1 mg dexamethasone suppression test in patients with adrenal adenomas and no features of overt hypercortisolism. Referent subjects were included if they had abdominal imaging and had no adrenal disorders. Patients and referent subjects had a baseline and a follow-up evaluation at least 10 months later. Differences were assessed using paired t-tests for (1) Frailty Index (FI)--calculated using a questionnaire containing 47 variables on comorbidities, symptoms, and daily living activities (frailty defined as FI>0.25) (2) physical function assessed using handgrip strength (Jamar Plus digital hand dynamometer), timed up-and-go test (time taken to rise from a chair, walk to and from 3 m, and sit down), gait speed, 6-minute walk test, and (3) Advanced Glycation End (AGE) Product (using AGE reader). Results: We evaluated 41 patients before and after adrenalectomy, and 31 referent subjects at baseline and follow-up visit, at a similar interval (median 1.6, IQR 1.2-2.0 vs 1.5 years, IQR 1.0-2.2, P=0.759). While sex distributions were no different between the 2 groups (women, 66% vs 84%, P=0.086), patients with MACS were older than the referent group (median age 57.3, IQR 48.8-66.9 vs 49.0, IQR 41.7-57.9 years, P=0.005). Post-adrenalectomy, FI decreased by a mean of 0.057 (SD 0.08), P<0.001 in patients, and remained unchanged in the referent group. AGE decreased in patients by 0.148 (SD 0.45), P=0.04 but not in referent subjects (-0.047, SD 0.242, P=0.5). Patients demonstrated no improvement in parameters of muscle strength: gait speed (mean change 0.305 m/s, P=0.453), 6-minute walk test (mean change 16.4 meters, P=0.201), dominant (mean Z score change -0.055, P=0.72) and nondominant (mean Z score change -0.199, P=0.192) hand grip muscle strength. At follow-up, both patients (mean change 1.897 seconds, P<0.001) and referent subjects (mean change=1.475 seconds, P<0.001) demonstrated a deterioration on the timed up-and-go test. Conclusions: While no improvement was seen in the parameters of muscle strength, adrenalectomy improved the frailty index in patients with MACS. In addition, AGE, a biomarker associated with cardiovascular morbidity, decreased after adrenalectomy, suggesting a beneficial cardiovascular impact of MACS reversal. Presentation: 6/1/2024

Understanding How Eccentric Hamstring Strength Affects Football Performance: The Scientific Secret To Fast Running

This study aimed to investigate the impact of eccentric hamstring strength, identified as a significant factor in the risk of hamstring injury, on maximum sprinting speed. Twenty-three football players competing in the Turkish Super League, with an average age of 25.12±3.22, were included in the study. The eccentric hamstring muscle strength of the athletes was measured using the N3 Nordic Hamstring Curl Exercise device. The maximum sprinting speeds of the players were determined by a GPS analyst. It was found that there was no significant relationship between eccentric hamstring strength on both dominant and non-dominant sides and maximum sprinting speed. Similarly, no significant relationship was found between the difference in eccentric hamstring strength between the two sides and maximum sprinting speed values (p>0.05). The study concluded that there is no association between eccentric hamstring muscle strength parameters and maximum sprinting speed in football players. As confirmed in this study, isolated maximum eccentric hamstring muscle strength alone does not appear to be the sole determinant parameter for horizontal force production during sprinting. However, further research is needed in this area.

Objective assessment of the effect of surgery on limb function after medial femoral condyle free flap harvest: biomechanical parameters

The aim of this study was to evaluate the influence of medial femoral condyle (MFC) free flap harvest on donor site muscle strength and kinematic parameters of gait. The study included 30 patients treated for head and neck squamous cell carcinoma who underwent reconstruction with an MFC free flap. In each case, the donor site was the left thigh. A dynamometer was used to measure muscle strength, in isokinetic bilateral mode and with concentric contraction for the extension/flexion knee pattern, at 18 months postoperative. In addition, kinematic data were obtained and evaluated. On statistical analysis, no significant difference in muscle strength of the quadriceps muscle was found between the left involved and right uninvolved lower extremities (P = 0.124). Also, when comparing hamstring strength, no statistically significant difference was found between the left involved and right uninvolved sides (P = 0.210). Moreover, spatiotemporal gait parameters did not differ significantly between the involved and uninvolved legs (all P > 0.05), and no differences in kinematic or kinetic parameters were observed. This study reports the effects of MFC free flap harvest on the knee muscle strength and locomotion of patients. For most biomechanical parameters investigated, there was no effect (positive or negative).

Rapid benefits in older age from transition to whole food diet regardless of protein source or fat to carbohydrate ratio: Arandomised control trial.

Plant-based diets reduces the risk of chronic conditions. The interaction between protein source and other macronutrients-fat (F) and carbohydrate (C)-has yet to be investigated. The aim was to assess the main and interactive effects of protein-source (plant vs. animal) and F:C (high or low) and the transition from an Australian diet to a whole food diet on various health markers in older individuals. This single-blinded, parallel, randomised experimental trial used a 2 × 2 factorial design to compare pro-vegetarian (70:30 plant to animal) versus omnivorous (50:50 plant to animal) diets at 14% protein and varying fat-to-carbohydrate ratios (high fat ~40% vs. low fat ~30%) over 4 weeks. Study foods were provided, alcohol consumption was discouraged, and dietary intake was determined through food records. Analysis included both RCT and observational data. Changes in appetite, palatability of diets, and dietary intake were assessed. Body composition, muscle strength, function, gut microbiome, and cardiometabolic health parameters were measured. Data from 113 (of the 128 randomised) individuals aged 65-75 years were analysed. Pro-vegetarian diets reduced diastolic blood pressure, total cholesterol and glucose levels. Moreover, the overall sample exhibited increased short-chain fatty acids and FGF21 levels, as well as improvements in body composition, function, and cardio-metabolic parameters irrespective of dietary treatment. Transitioning to a diet rich in fruit, vegetables, fibre, and moderate protein was associated with improved health markers in older age, with added benefits from pro-vegetarian diets. Further research on long-term effects is needed.

Comparison of the efficacy of auricular vagus nerve stimulation and conventional low back rehabilitation in patients with chronic low back pain

BackgroundIn recent years, human and animal studies have provided increasing evidence that vagus nerve stimulation (VNS) can produce analgesic effects as well as alleviating resistant epilepsy and depression. Our study was designed to compare the efficacy of transcutaneous auricular vagus nerve stimulation with conventional low back rehabilitation in patients with chronic low back pain (CLBP). MethodsSixty patients with LBP were randomly divided into two groups. Group 1 received conventional rehabilitation and home exercise, and Group 2 received transcutaneous auricular VNS and home exercise. Both groups received treatment five days a week for three weeks. Trunk mobility (Modified Schober test, fingertip-to-floor test), muscle strength (CSMI-Cybex Humac-Norm isokinetic dynamometer and Lafayette manual muscle strength measuring device), trunk endurance, balance tests, Visual Analog Scale, Beck Depression Scale, Pittsburgh Sleep Quality Index, Oswestry Disability Index were evaluated. ResultsAt the end of three weeks, within-group assessment results showed positive effects on mobility, functional status, depression and sleep in all groups (p < 0.05). Pain level, endurance time and flexion trunk muscle strength results showed more improvement in Group 2 (p < 0.05). Some parameters of isokinetic lower extremity quadriceps muscle strength and fall risk scores showed a significant improvement in Group 1 (p < 0.05). DiscussionVNS has been observed to be more effective on pain, trunk muscle strength and endurance duration and sleep status. Auricular VNS may be included in the treatment of patients with CLBP in whom conventional physical therapy is inadequate or not applicable.

Muscle Strength Identification Based on Isokinetic Testing and Spine Musculoskeletal Modeling.

Subject-specific spinal musculoskeletal modeling can help understand the spinal loading mechanism during human locomotion. However, existing literature lacks methods to identify the maximum isometric strength of individual spinal muscles. In this study, a muscle strength identification method combining isokinetic testing and musculoskeletal simulations was proposed, and the influence of muscle synergy and intra-abdominal pressure (IAP) on identified spinal muscle strength was further discussed. A multibody dynamic model of the spinal musculoskeletal system was established and controlled by a feedback controller. Muscle strength parameters were adjusted based on the measured isokinetic moments, and muscle synergy vectors and the IAP piston model were further introduced. The results of five healthy subjects showed that the proposed method successfully identified the subject-specific spinal flexor/extensor strength. Considering the synergistic activations of antagonist muscles improved the correlation between the simulated and measured spinal moments, and the introduction of IAP slightly increased the identified spinal extensor strength. The established method is beneficial for understanding spinal loading distributions for athletes and patients with sarcopenia.

#360 Short-term treatment with medium cut-off dialyzers increases muscle mass with preserved fat tissue in maintenance HD patients

Abstract Background and Aims Protein-energy wasting is a significant complication of maintenance hemodialysis (HD) patients characterized by reduced fat or muscle mass and strength. The combination of non-modifiable general and disease-related factors, such as uremic toxin accumulation and systemic inflammation, is responsible for this condition. Medium cut-off (MCO) membranes are designed to provide clearance of large-middle molecular weight uremic toxins and inflammatory cytokines without causing loss of albumin. This study aimed to investigate the short-term effect of MCO dialyzers on fat tissues and muscle mass. Method We conducted a prospective, single-center cross-over study on maintenance HD patients treated with regular low-flux (LF) dialyzers. Fat tissues were measured with a skinfold caliper and mid-upper arm circumference. Muscle thickness and strength parameters from six different muscle groups were evaluated with ultrasound. The baseline (control) parameters were measured under LF dialyzers, and the measurements were repeated two weeks after switching to MCO dialyzers for the patients ordered by their clinicians according to the clinical indications. Results The median age was 69.5 (50.3,78.8) years, and 60% of the patients were female. Two weeks after switching to MCO, the Kt/Vs, urea reduction ratios, mean serum albumin, dry weight, and body mass index scores were similar. Mean skinfold thickness and mid-upper arm circumference were 15 mm (11,17) and 28mm (27,30) under LF and 16mm (14,19) and 28mm (27,30) under MCO dialyzers (p=0.82 and p=0.27). Rectus abdominis and external oblique muscle groups remained similar. Internal and external oblique muscle thickness were significantly increased (p=0.002 and p=0.001). Mean rectus femoris and gastrocnemius medialis (GKM) thicknesses were 1.19cm (0.99,1.33) and 1.16cm (0.9,1.4) under LF and 1.31cm (1.20, 1.40) and 1.24cm (0.95,1.40) under MCO dialyzers (p=0.002 and p=0.02). Mean GKM fibrile length and pennation angles were 2.4cm (2.2,2.8) and 20o (18,23) under LF and 2.7cm (2.4, 2.9) and 22o (19,24) under MCO dialyzers (p=0.007 and p=0.001). Conclusion Our study showed that MCO dialyzers increase muscle mass with preserved fat tissues in HD patients, short-term follow-up. This favorable effect might be due to the clearance of uremic toxins, which cannot be removed with conventional methods. If long-term studies support our findings, MCO dialyzers would be a milestone for the treatment of sarcopenia in HD patients.

Different roles of circulating and intramuscular GDF15 as markers of skeletal muscle health.

Growth Differentiation Factor 15 (GDF15) is a mitokine expressed in response to various stresses whose circulating levels increase with age and are associated with numerous pathological conditions, including muscle wasting and sarcopenia. However, the use of circulating GDF15 (c-GDF15) as a biomarker of sarcopenia is still debated. Moreover, the role of GDF15 intracellular precursor, pro-GDF15, in human skeletal muscle (SM-GDF15) is not totally understood. In order to clarify these points, the association of both forms of GDF15 with parameters of muscle strength, body composition, metabolism and inflammation was investigated. the levels of c-GDF15 and SM-GDF15 were evaluated in plasma and muscle biopsies, respectively, of healthy subjects (HS) and patients with lower limb mobility impairment (LLMI), either young (<40 years-old) or old (>70 years-old). Other parameters included in the analysis were Isometric Quadriceps Strength (IQS), BMI, lean and fat mass percentage, Vastus lateralis thickness, as well as circulating levels of Adiponectin, Leptin, Resistin, IGF-1, Insulin, IL6, IL15 and c-PLIN2. Principal Component Analysis (PCA), Canonical Discriminant Analysis (CDA) and Receiving Operating Characteristics (ROC) analysis were performed. c-GDF15 but not SM-GDF15 levels resulted associated with decreased IQS and IGF-1 levels in both HS and LLMI, while only in LLMI associated with increased levels of Resistin. Moreover, in LLMI both c-GDF15 and SM-GDF15 levels were associated with IL-6 levels, but interestingly SM-GDF15 is lower in LLMI with respect to HS. Furthermore, a discrimination of the four groups of subjects based on these parameters was possible with PCA and CDA. In particular HS, LLMI over 70 years or under 40 years of age were discriminated based on SM-GDF15, c-GDF15 and Insulin levels, respectively. our data support the idea that c-GDF15 level could be used as a biomarker of decreased muscle mass and strength. Moreover, it is suggested that c-GDF15 has a different diagnostic significance with respect to SM-GDF15, which is likely linked to a healthy and active state.

The impact of guideline recommended protein intake on mortality and length of intensive care unit and hospital stay in critically ill adults: A systematic review

International guidelines recommend a target protein intake of ≥1.2 g/kg/day to all critically ill patients for optimal outcomes. There are however various conflicting data related to this recommendation. The primary objective of this review was to compare a protein intake group (≥1.2 g/kg/day) with a lower protein intake group (<1.2 g/kg/day) in critically ill adult patients on mortality, length of intensive care unit (ICU) and hospital stay. Secondly, the effect of protein intake on length of mechanical ventilation, adverse nutrition-related events and muscle mass and strength parameters were investigated. Sixteen randomised controlled trials (RCTs) of adult patients admitted to an intensive or high care unit and receiving nutrition support in the form of enteral- and/or parenteral nutrition were selected against prespecified eligibility criteria. Two independent reviewers extracted relevant data and assessed the risk of bias of the included studies. Review Manager 5.4.1 was used to analyse data and GRADE (Grading of Recommendations, Assessment, Development, and Evaluations) was used to evaluate the certainty of the evidence. The higher protein group, when compared to the lower protein group, probably results in little to no difference in mortality (risk ratio [RR] 1.01; 95% confidence interval [CI]: 0.89 to 1.14; moderate-certainty evidence); with a probable slight increase in length of ICU stay (mean difference [MD] 0.33; 95% CI -0.57 to 1.23; moderate-certainty) and length of hospital stay (MD 1.72; 95% CI -0.58 to 4.01; moderate-certainty evidence), on average. For secondary outcomes, it was found that the higher protein group probably does not reduce the length of mechanical ventilation (MD 0.08; 95% CI -0.38 to 0.53; moderate-certainty evidence). Higher protein group probably reduces the occurrence of diarrhoea and high gastric residual volume and may reduce the occurrence of constipation. It may also increase nitrogen balance (MD 3.66; 95% CI 1.81 to 5.51; low-certainty evidence). Importantly, there does not seem to be harm associated with the higher protein group, though it should be mentioned that for many of the adverse events in this study, the certainty of evidence was low or very low.

Nonalcoholic Fatty Liver Disease, Bone and Muscle Quality in Prolactinoma: A Pilot Study

Objective: Hyperprolactinemia has negative impacts on metabolism and musculoskeletal health. In this study, individuals with active prolactinoma were evaluated for nonalcoholic fatty liver disease (NAFLD) and musculoskeletal health, which are underemphasized in the literature.Methods: Twelve active prolactinoma patients and twelve healthy controls matched by age, gender, and BMI were included. Magnetic resonance imaging-proton density fat fraction (MRI-PDFF) was used to evaluate hepatic steatosis and magnetic resonance elastography (MRE) to evaluate liver stiffness measurement (LSM). Abdominal muscle mass, and vertebral MRI-PDFF was also evaluated with MRI. Body compositions were evaluated by dual energy X-ray absorptiometry (DXA). The skeletal muscle quality (SMQ) was classified as normal, low and weak by using “handgrip strength/appendicular skeletal muscle mass (HGS/ASM)” ratio based on the cut-off values previously stated in the literature.Results: Prolactin, HbA1c and CRP levels were higher in prolactinoma patients (p<0.001, p=0.033 and p=0.035, respectively). The median MRI-PDFF and MRE-LSM were 3.0% (2.01-15.20) and 2.22 kPa (2.0-2.5) in the prolactinoma group and 2.5% (1.65-10.00) and 2.19 kPa (1.92-2.54) in the control group, respectively and similiar between groups. In prolactinoma patients, liver MRI-PDFF showed a positive and strong correlation with the duration of disease and traditional risk factors for NAFLD. Total, vertebral and pelvic bone mineral density was similar between groups, while vertebral MRI-PDFF tended to be higher in prolactinoma patients (p=0.075). Muscle mass and strength parameters were similar between groups, but HGS/ASM tended to be higher in prolactinoma patients (p=0.057). Muscle mass was low in 33.3% of prolactinoma patients and 66.6 of controls. According to SMQ, all prolactinoma patients had normal SMQ, whereas 66.6% of the controls had normal SMQ.Conclusion: Prolactinoma patients demonstrated similar liver MRI-PDFF and MRE-LSM to controls despite their impaired metabolic profile and lower gonadal hormone levels. Hyperprolactinemia may improve muscle quality in prolactinoma patients despite hypogonadism.

Isokinetic Knee Muscle Strength Parameters and Anthropometric Indices in Athletes with and without Hyperextended Knees.

Background and Objectives: Hypermobility has been linked to decreased knee performance, including isokinetic and isometric knee strength. This study aimed to determine whether athletes with and without knee hyperextension have different hamstring-to-quadriceps strength (H/Q) ratios and to investigate the associations between knee hyperextension indices and H/Q ratios and anthropometric characteristics. Materials and Methods: The sample consisted of 47 healthy male athletes without knee injuries aged 23.48 ± 3.54 years. The variables included the degree of knee hypermobility, isokinetic parameters of the leg musculature, and anthropometric indices. Differences between athletes with and without hyperextension were calculated using an independent sample t-test, effect sizes, and discriminant analysis, while associations between the variables were checked by Pearson's correlation coefficient and multiple regression analysis. Results: Athletes with hyperextended knees had shorter legs (t value = -2.23, p = 0.03, moderate ES) and shins (t = -2.64, p = 0.01, moderate ES) and a lower H/Q ratio at an angular velocity of 60°/s (t = -2.11, p = 0.04, moderate ES) than those in the nonhyperextended group did; these differences were supported by discriminant analysis (Wilks' L = 0.60, p = 0.01). An increase in the H/Q ratio at an angular velocity of 60°/s was associated with the degree of knee hypermobility (R = -0.29, p = 0.04). Conclusions: This research showed that athletes with knee hypermobility have weaker hamstring strength and thus a lower H/Q strength ratio at lower angular velocities. These findings suggest that targeted strength training programs for leg (i.e., hamstrings) muscles should help individuals with knee hypermobility.

Intra-session reliability of isometric muscle strength of the bilateral standing press in female handball players.

Systematizing reliable protocols and procedures for strength assessment in handball has allowed for a more thorough kinetic analysis and increased precision in detecting training-induced changes in muscular strength. The evaluation of upper limb strength with a bilateral standing press (BSP) exercise in handball players approximates blocking actions in the defensive phase, pushing and fixation. The aim of this study was to analyze the relative and absolute reliability of intra-session comparisons in an isometric peak muscle strength protocol in a bilateral standing press (BSP) exercise among female handball players. Sixteen young female handball players at an international level, aged between 22 ± 4 years, with no prior experience in using functional electromechanical dynamometers (FEMD) participated in this study. The participants initiated the assessment of maximum isometric force in a bipedal stance with a forward projection of the dominant foot between 20 and 30 cm. The knees were kept semi-flexed, and the hip extension of the non-dominant limb ranged from 15 to 20°. Bilateral anterior push of the upper limb was performed with shoulder abduction and elbow flexion at 90°, maintaining a pronated hand position. Participants were instructed to exert three sets of maximal force for 5 s in BSP exercise. Relative reliability was assessed using the model intraclass correlation (ICC) and absolute reliability was assessed using the coefficient of variation (CV) and standard error of measurement (SEM). For this study, the parameters of maximum and mean muscle strength were considered. The results demonstrated high relative reliability (ICC 0.93-0.97) and absolute reliability (SEM 0.19-2.79) y (CV 4.78-9.03) for both mean force and peak force, with no significant differences between the sets (p > 0.05), indicating a negligible effect size (0.01-0.12). The mean and peak isometric muscle strength for the BSP exercise controlled with FEMD in female handball players exhibits high relative and absolute reliability between series.

Body composition and functional activity in men with heart failure

Aim. To assess the body composition and functional activity (FA) parameters in men with heart failure (HF) of various nature depending on the stage, class and echocardiographic characteristics of the disease.Material and methods. The study included 100 men aged 23-70 years. The main group consisted of 60 men with HF, the control group — 40 men without HF. Quantitative body composition assessment (fat, lean and bone body mass) was carried out using dual-energy X-ray absorptiometry (DXA). Physical activity was assessed using handgrip test, short physical performance battery (SPPB) test, 6-minute walk test (6MWT), and Timed Up and Go (TUG) test.Results. In the HF group, there were a significant decrease in total bone mass, trunk and limb bone mass, total muscle mass, trunk and limbs’ muscle mass, appendicular skeletal muscle index (ASMI), and FA as HF class increased. Fat mass did not differ in individuals with different HF class and stage. HF class was an independent factor in the reduction of total bone mass (b=-301,9, p=0,015), total muscle mass (b=-1903, p=0,03), limb bone mass (b=-147,6, p=0,013) and appendicular muscle mass (AMM) (b=-1903, p=0,001). Total bone mass (b=-2,637, p=0,02) and AMM (b=-3,512, p=0,01) were independently associated with the Vasilenko-Strazhesko HF stage. AMM also had an independent association with left ventricular ejection fraction (LVEF) (b=0,274, p=0,03). The average body composition scores did not differ between the study and control groups, while the scores of handgrip test, 6MWT, SPPB and TUG test were significantly worse in the HF group. NYHA HF class, stage of HF, LVEF, left ventricular end-diastolic volume (LVEDV) and pulmonary artery systolic pressure (PASP) made an independent contribution to FA decrease in men with HF.Conclusion. In patients with HF, there was deterioration in musculoskeletal parameters depending on HF class, stage and LVEF, without significant differences compared to the control group. There was no association of fat mass with the disease, clinical and echocardiographic characteristics. The average parameters of muscle strength and tests of FA were reduced in men with HF compared with the control group and depended on the NYHA class and stage of HF, LVEF, LVEDV, and PASP.

The Effect of Proprioceptive Neuromuscular Facilitation Techniques on Muscular Strength in Patients with Knee Osteoarthritis: A Quasi-Experimental Study

Background: Knee osteoarthritis is a prevalent chronic musculoskeletal problem among older people, leading to pain, muscle weakness, and a decline in the quality of life. Objectives: This study aimed to investigate the impact of proprioceptive neuromuscular facilitation techniques on the muscle strength of patients with knee osteoarthritis. Methods: This quasi-experimental study was conducted on all patients with knee osteoarthritis who visited orthopedic offices in Darab City in 2021. A non-probability sampling method was used to select 50 eligible patients, who were then divided into 2 groups: an experimental group and a control group. The allocation of participants into these groups was done by a block randomization method. The experimental group underwent proprioceptive neuromuscular facilitation techniques for eight weeks, with two sessions per week lasting 30 - 45 minutes. In contrast, the control group received only routine care. Muscle strength in both groups was evaluated using the manual muscle test scale before, four weeks, and immediately after the intervention. The collected data were analyzed using SPSS 21, descriptive statistics (such as central tendency and dispersion indices), independent t, chi-square, Fisher’s exact, Mann-Whitney U, Kolmogorov-Smirnov, Wilcoxon, and repeated measures ANOVA tests. A significance level of 0.05 was considered. Results: Fifty patients (24% male and 76% female) with a mean age of 53.6 ± 10 completed this study. There was no statistically significant difference by mean scores of muscle strength parameters, including degree (2.8 ± 0.4 vs. 2.8 ± 0.3), the percentage of normality (45 ± 10 vs. 44 ± 12), and scale (2.8 ± 0.4 vs. 2.8 ± 0.3) between the intervention group and the control group on the before of intervention, respectively. However, a significant difference was observed by degree (3.6 ± 0.6 vs. 2.8 ± 0.3; P = 0.001), the percentage of normality (65 ± 14 vs. 45 ± 9; P = 0.001), and scale (3.5 ± 0.6 vs 2.8 ± 0.3; P = 0.001) between the intervention group and the control group, respectively, at the end of the intervention. Conclusions: The proprioceptive neuromuscular facilitation techniques could improve the muscle strength of patients with knee osteoarthritis. If this finding is confirmed in other studies, healthcare workers should use these techniques for the benefit of these patients.

The Interplay between Muscular Grip Strength and Bone Mineral Density with Consideration of Metabolic and Endocrine Parameters in Individuals with Turner Syndrome.

Patients with Turner syndrome (TS) often face skeletal and muscular challenges, including reduced bone mineral density (BMD) and muscle weakness. This comprehensive study sheds light on the complex interplay between muscle strength, BMD, and metabolic and endocrine parameters in TS and healthy subjects. A cross-sectional study involving 42 TS patients and 70 healthy women was conducted. All patients had their BMD determined in the L1-L4 lumbar spine section and in the whole skeleton as well as the parameters of body fat mass (BF), and visceral fat mass (VF) were also determined. The maximum gripping force was measured with a hydraulic manual dynamometer. In addition, a number of blood hormonal and metabolic parameters were determined. In the TS group, hand grip strength correlated positively with triglyceride levels but not with BMD. Healthy individuals had a positive link between hand grip strength and BMD, while patients with TS did not show a significant association between the two. A trend suggested that longer recombinant human growth hormone (rhGH) therapy might improve BMD in the L1-L4 region. Multiple linear regression analysis revealed that muscle strength assessment may be a potential exponent of reduced BMD, and also used clinically in young adult women but not in individuals with TS. The relationship between BMD variables and hand grip might differ between the two groups, potentially indicating distinct musculoskeletal characteristics in TS patients. Longer rhGH therapy in TS patients may have a positive effect on BMD in the L1-L4 region. Understanding the intricate relationships between these factors is important for optimizing clinical management strategies and improving the quality of life for TS patients.

MOTS-c Serum Concentration Positively Correlates with Lower-Body Muscle Strength and Is Not Related to Maximal Oxygen Uptake-A Preliminary Study.

The mitochondrial open reading frame of 12S rRNA-c (MOTS-c) is a mitochondrial-derived peptide that regulates the nuclear genome during stressful conditions such as hypoxia, which is typical of exercise and training. We aim to mainly investigate the relationship between serum MOTS-c concentration and muscle strength parameters measured during the countermovement jump test with oxygen consumption (VO2) measured during the cardiopulmonary exercise test to exhaustion. Physically active healthy volunteers (17 male, three female, median age 30 years), not involved in any regular exercise program or participating in any sports competitions, performed five consecutive countermovement jump tests and cardiopulmonary exercise tests until maximal exhaustion and underwent a body composition assessment by means of bioelectrical impedance analysis, and had serum MOTS-c concentration measured at rest. Serum MOTS-c concentration was positively correlated with the average power and average and maximal force of the jumps, both overall muscle mass and leg muscle mass, but not with body fat percentage. There was no correlation with peak VO2. A higher serum MOTS-c concentration is associated with greater muscle mass, force, and power generated during jumping in healthy individuals but not exercise capacity reflected by peak VO2. More studies are needed to better understand the physiological and clinical values of these findings and why MOTS-c is better associated with measures of muscle strength and not endurance in physically active people.

Effect of vitamin D supplementation on circulating level of autophagosome protein LC3A, inflammation, and physical performance in knee osteoarthritis.

Aberrant autophagic activity is observed in osteoarthritic joints. Vitamin D was shown to alleviate not only osteoarthritis severity, but also autophagy process. However, the influence of vitamin D on autophagy in knee osteoarthritis (KOA) remains ambiguous. This study aimed to determine the effect of vitamin D2 on serum levels of autophagosome protein LC3A in patients with KOA and whether LC3A levels were correlated with serum 25-hydroxyvitamin D (25(OH)D) and clinical outcomes of patients with KOA. A total of 165 patients with KOA and 25 healthy controls were recruited. Vitamin D2 (ergocalciferol) was administered to patients with KOA at a weekly dosage of 40,000 IU. Serum LC3A, knee pain and functional scores, muscle strength, physical performance, and biochemical parameters were examined before and after 6 months of vitamin D2 supplementation. Serum LC3A levels were significantly higher in patients with KOA than healthy controls. In patients with KOA, vitamin D2 supplementation significantly decreased serum LC3A levels. Furthermore, baseline levels of serum LC3A were significantly associated with radiographic severity, pain and functional scores, total cholesterol, hs-CRP, IL-6, protein carbonyl, and serum 25(OH)D. After adjusting for established confounders, independent relationships among serum LC3A and radiographic severity, pain and functional scores, total cholesterol, hs-CRP, IL-6, protein carbonyl, and serum 25(OH)D were also observed. Vitamin D2 supplementation was shown to not only decrease serum levels of LC3A, inflammatory markers, as well as oxidative stress, but also improve muscle strength and physical performance in patients with KOA.

Which trunk muscle parameter is the best predictor for physical function in older adults?

BackgroundDespite preliminary evidence demonstrating the relevance of trunk muscle strength for physical function in older adults, it is not clear which muscle-related trunk parameter is the best predictor for physical functions. Therefore, this study aimed to compare trunk muscle morphology or strength parameters regarding their predictive ability for physical functions. MethodsSeventy-four older adults (38 men, 36 women, mean age 76.85 years) were tested for maximum absolute and relative isokinetic trunk flexion and extension strength, trunk lean mass, and trunk muscle quality. Functional assessment included normal and fast walking speed, repeated sit-to-stand transfer, timed up and go, and postural sway during a closed-feet and a semi-tandem stance adjusted for body height. Pearson's correlations were used to compare relationship between trunk strength adjusted and unadjusted for body weight to physical functions. Linear regression analysis including sex and age as co-variables was performed between trunk muscle and functional test parameters. ResultsRelative back extension strength was the most consistent significant predictor for all physical function tests (p = 0.004–0.04) except for postural sway. Relative trunk flexion strength was related to normal walking speed (p = 0.024). Trunk lean mass was related to timed up and go performance (p = 0.024). ConclusionRelative back extension strength is associated with better performance in nearly all standard tests for physical function in older adults, while trunk flexion strength and lean mass seem to play a minor role. Our findings emphasize the importance of trunk muscle strength, especially the back extensor muscles, for physical function in older adults.