Maximum Grip Strength Research Articles

Effects of Different Loading Programs on Finger Strength in Rock Climbers.

Climbing places high loads through the hands and fingers, and climbers may benefit from specific finger strength training (hangboarding) protocols. The purpose of this study was to evaluate the effect of a 10-minute low intensity hangboard finger strengthening protocol ("Abrahangs"), compared with the generally accepted Max Hangs protocol for training maximal grip strength. We retrospectively evaluated the change in grip strength and Strength: Weight following Max Hangs, Abrahangs, or the two protocols performed concurrently in rock climbers who used the Crimpd app to log their training. Users who had completed two finger strength tests within a 4-16-week period were included. Climbers were grouped by the number of training sessions into: "Climbing Only", "Abrahangs Only", "Max Hangs Only" and "Both" Max Hangs and Abrahangs. Frequent low intensity finger loading was as effective at improving grip strength in climbers as training with maximal loads. Additionally, combining low intensity and maximal load training resulted in additive strength gains. These results suggest that low-intensity long duration holds provide a promising training paradigm for training finger strength that is gentle enough to incorporate into existing training programs.

Surface electromyography character of upper limb muscle after open reduction combine with ulnar osteotomy in children with neglected Monteggia fracture.

This study aims to investigate the surface electromyography (sEMG) characteristics of upper limb muscles in children with neglected Monteggia fracture after open reduction of radial head dislocation and ulna osteotomy and bone grafting internal fixation, and to understand the recovery of muscle activity in children after operation, provide reference for clinical rehabilitation. A retrospective analysis was conducted on sixteen children with neglected Monteggia fracture who underwent ulna osteotomy at our hospital from January 2021 to August 2022. The biceps brachii, triceps brachii, flexor carpi radialis, and extensor carpi ulnaris muscle activities were recorded during grip strength tests, flexion and extension of elbow joint while holding a 1 kg dumbbell, as well as gripping tasks. The root mean square (RMS) values of sEMG signals, co-contraction ratio, and elbow joint function scores were compared between pre- and post-operation periods as well as between the affected side and unaffected side. The preoperative maximum grip strength, as well as the average RMS values of flexor carpi radialis and average RMS value of extensor carpi ulnaris on the affected side were significantly lower. After surgery, both the maximum RMS value of biceps brachii and maximum and average RMS value of extensor carpi ulnaris on the affected side remained lower. Prior to surgery, when performing elbow flexion and extension tests while holding a 1 kg dumbbell, both mean RMS values of biceps brachii and flexor carpi radialis on the affected side were smaller. However, after surgery, there was an increase in mean RMS values of biceps brachii on the affected side. Furthermore, postoperative elbow function scores were significantly higher than preoperative scores. Open reduction of radial head dislocation combined with ulna osteotomy and bone grafting can achieve good functional activities in the treatment of neglected Monteggia fractures in children. The EMG activity of the extensor carnosus ulnalis muscle on the affected side related to grip strength was low, and the desired effect was not achieved within the expected time.

Effects of o-tDCS and tDCS on Maximal Grip Strength

Effects of o-tDCS and tDCS on Maximal Grip Strength

A GWAS for grip strength in cohorts of children-Advantages of analysing young participants for this trait.

Grip strength (GS) is a proxy measure for muscular strength and a predictor for bone fracture risk among other diseases. Previous genome-wide association studies (GWASs) have been conducted in large cohorts of adults focusing on scores collected for the dominant hand, therefore increasing the likelihood of confounding effects by environmental factors. Here, we perform the first GWAS meta-analyses on maximal GS with the dominant (GSD) and non-dominant (GSND) hand in two cohorts of children (ALSPAC, N = 5450; age range = 10.65-13.61; Raine Study, N = 1162, age range: 9.42-12.38 years). We identified a novel significant association for GSND (rs9546244, LINC02465, p = 3.43e-08) and replicated associations previously reported in adults including with a HOXB3 gene marker that shows an expression quantitative trait locus (eQTL) effect. Despite a much smaller sample (~3%) compared with the UK Biobank we replicated correlation analyses previously reported in this much larger adult cohort, such as a negative correlation with coronary artery disease. Although the results from the polygenic risk score (PRS) analyses did not survive multiple testing correction, we observed nominally significant associations between GS and risk of overall fracture, as previously reported, as well ADHD which will require further investigations. Finally, we observed a higher SNP-heritability (24%-41%) compared with previous studies (4%-24%) in adults. Overall, our results suggest that cohorts of children might be better suited for genetic studies of grip strength, possibly due to the shorter exposure to confounding environmental factors compared with adults.

Relationship between fatigue and quantitative electromyography findings in patients with myasthenia gravis

BackgroundFatigue is a common complaint among patients with myasthenia gravis (MG). In this study, we investigated the alterations in muscle morphology in patients with MG experiencing fatigue using quantitative electromyography (QEMG), and explored the relationship between electrophysiological findings and the severity of both fatigue and disease. MethodsWe performed QEMG of the biceps brachii muscle using the peak ratio method and multi-motor unit potential (MUP) analysis across three groups: 18 MG patients with fatigue, 34 MG patients without fatigue, and 33 healthy subjects. Stimulated single-fiber EMG was performed on the frontalis muscle. The severity of perceived fatigue and disease was subsequently assessed using the quantitative myasthenia gravis (QMG) score, the MG-activities of daily living (MG-ADL) profile, self-reported fatigue questionnaires, and handgrip strength measurements. ResultsThe QEMG study revealed a reduced mean MUP duration and size index (SI), in addition to an increased peak ratio in patients with MG (p < 0.05), which tended to be more pronounced in those experiencing fatigue. Compared to healthy subjects, MG patients with fatigue displayed a myopathic pattern characterised by a high peak ratio, short duration, and small-amplitude MUPs, without any increase in the number of phases or small time intervals. The mean peak ratio was positively correlated with the QMG, MG-ADL, and Fatigue Impact Scale total and physical subscores (p < 0.05). Further, MG patients with fatigue exhibited reduced maximum grip strength, which was positively correlated with the mean MUP duration, amplitude, SI, and thickness, and negatively correlated with the mean peak ratio (p < 0.05). No significant differences were observed in the jitter or block measurements (p > 0.05). ConclusionsThe present study investigated electrophysiological findings that were not considered or theorised in prior studies on patients with MG experiencing fatigue. The results of this study suggest that myopathic changes may be a critical pathophysiological component underlying the fatigue associated with MG.

Interrater Reliability and Precision of a Novel Hand Strength Assessment and Treatment Device: The GripAble.

Occupational therapy practitioners need modern tools for the assessment of maximal grip strength in clinical and remote settings. To establish the (1) interrater reliability and (2) precision of the GripAble among three raters with different expertise in occupational therapy when testing healthy participants, and to (3) evaluate the relative reliabilities of different approaches to estimating grip strength (i.e., one trial, mean of two trials, and the mean of three trials). Measurement study. Minnesota Translational Musculoskeletal and Occupational Performance Research Lab, University of Minnesota, Minneapolis. Thirty volunteers, age ≥18 yr, without any hand problems. Using GripAble, three occupational therapy raters with varied experience measured the maximal grip strength of the dominant and nondominant hands of all participants. Using the mean of three trials when testing grip strength with GripAble adds precision. GripAble has excellent interrater reliability (i.e., intraclass correlation coefficient > .75) and acceptable precision (minimal detectable change < 15%) among healthy adults. GripAble allows occupational therapy practitioners with different experiences to assess grip strength in healthy hands quickly, precisely, and with excellent reliability. Additional research is needed on its psychometrics in clinical populations and capacities in remote monitoring and exergaming. Plain-Language Summary: The results of this study show that grip strength, an important biomarker and commonly assessed construct in occupational therapy, can be evaluated reliably, precisely, and rapidly with GripAble. The use of GripAble by occupational therapy practitioners in clinical settings may help to build an infrastructure for remote measurements and exergaming interventions in the future.

LC/MS-Based Untargeted Lipidomics Reveals Lipid Signatures of Sarcopenia.

Sarcopenia, a multifactorial systemic disorder, has attracted extensive attention, yet its pathogenesis is not fully understood, partly due to limited research on the relationship between lipid metabolism abnormalities and sarcopenia. Lipidomics offers the possibility to explore this relationship. Our research utilized LC/MS-based nontargeted lipidomics to investigate the lipid profile changes as-sociated with sarcopenia, aiming to enhance understanding of its underlying mechanisms. The study included 40 sarcopenia patients and 40 control subjects matched 1:1 by sex and age. Plasma lipids were detected and quantified, with differential lipids identified through univariate and mul-tivariate statistical analyses. A weighted correlation network analysis (WGCNA) and MetaboAna-lyst were used to identify lipid modules related to the clinical traits of sarcopenia patients and to conduct pathway analysis, respectively. A total of 34 lipid subclasses and 1446 lipid molecules were detected. Orthogonal partial least squares discriminant analysis (OPLS-DA) identified 80 differen-tial lipid molecules, including 38 phospholipids. Network analysis revealed that the brown module (encompassing phosphatidylglycerol (PG) lipids) and the yellow module (containing phosphati-dylcholine (PC), phosphatidylserine (PS), and sphingomyelin (SM) lipids) were closely associated with the clinical traits such as maximum grip strength and skeletal muscle mass (SMI). Pathway analysis highlighted the potential role of the glycerophospholipid metabolic pathway in lipid me-tabolism within the context of sarcopenia. These findings suggest a correlation between sarcopenia and lipid metabolism disturbances, providing valuable insights into the disease's underlying mechanisms and indicating potential avenues for further investigation.

Psychometric properties of the modified reaching performance scale in persons with multiple sclerosis

BackgroundA valid and reliable assessment tool to describe the quality of the movement pattern of reaching can provide valuable insights into motor performance deficits in persons with MS (pwMS). The Reaching Performance Scale, developed for stroke, is a promising scale to assess movement patterns in pwMS. However, psychometric properties of the scale are lacking in pwMS. ObjectivesFirstly, to investigate the content validity of the modified Reaching Performance Scale for application in patients with MS (mRPS). Secondly, to investigate the psychometric properties (within- and between-session reliability and concurrent validity) of the mRPS for pwMS. MethodsForty-five pwMS (mean EDSS 6.6 pt, IQR 6–7.5) executed the mRPS that rates the quality of movement patterns and compensations during reach to grasp tasks. The content validity was determined by an expert panel based on observations of subjects performing the RPS. The reliability was based on five repetitions within one day, and between two days. For the concurrent validity, outcome measures at two levels of the International Classification of Functioning were correlated with the mRPS: Body Structure and Function level: Fugl-Meyer Assessment of the Upper Limb (FMA-UL), maximal isometric hand grip strength (HGS; Activity level: Action Research Arm Test (ARAT), Box and Blocks Test (BBT), Nine Hole Peg Test (NHPT) and Trunk Impairment Scale 2.0 (TIS 2.0) as well as perceived performance by the Manual Ability Measure-36 (MAM-36). ResultsScale modifications were made only on the ratings of the trunk displacement subscale. The mRPS had excellent agreement scores for within-session reliability (range of Kappa between 0.85 and 0.98) and moderate-to-excellent agreement scores for between-session reliability (K: 0.66–1.00). Regarding validity, the mRPS was highly correlated with the ARAT (rho=0.74, p < 0.001), followed by moderate correlations with trunk performance (TIS 2.0, rho= 0.61, p < 0.001), hand function (BBT: rho=0.64, p < 0.001; NHPT: rho=-0.61, p < 0.001) and perceived performance (MAM36 rho= 0.53, p < 0.001). ConclusionThe mRPS is a reliable measurement tool to describe the movement pattern quality and motor compensations used during reaching in pwMS. Concerning concurrent validity, the mRPS is partially related to other measures of upper limb and trunk performance.

Association between relative muscle strength and cardiovascular disease among middle-aged and older adults in China

BackgroundThe association between sarcopenia and cardiovascular disease (CVD) is well known. However, the clinical diagnosis of sarcopenia is complex and not suitable for early clinical identification and prevention of CVD. Relative muscle strength (RMS) is a relatively quantitative and straightforward indicator, but its association with CVD remains unclear. Hence, the objective of this research was to investigate the correlation between RMS and CVD incidence.MethodsThis was a cross-sectional study, using data from the China Health and Retirement Longitudinal Study (CHARLS) in 2011. CVD events were assessed through self-reported physician diagnoses. The RMS was determined by dividing the maximum grip strength by the appendicular skeletal muscle mass (ASM). This study used multivariate logistic regression and restricted cubic spline (RCS) curves to explore the correlation between RMS and CVD incidence. Additionally, we conducted subgroup analyses to provide additional evidence supporting the association between the two variables.ResultsA total of 8,733 people were included in our study, with 1,152 (13.19%) CVD patients and 7,581 (86.81%) non-CVD patients. When the data were grouped according to quartiles (Q) of RMS, the inverse association between CVD and RMS remained statistically significant even after controlling for all potential confounding factors. Compared with participants in Q1 of RMS, the ORs (95% CIs) of CVD among those in Q2-Q4 were 0.99 (0.83, 1.17), 0.81 (0.67, 0.98), and 0.70 (0.57, 0.85), respectively. Moreover, the RCS results showed a negative linear correlation between the RMS and CVD incidence (P for nonlinearity = 0.555). Subgroup analysis revealed no significant interaction in any of the groups except for the sex group (P for interaction = 0.046).ConclusionOur study indicated a stable negative correlation between RMS and CVD incidence. RMS is helpful for the early identification and prevention of CVD.

RAZMERJE MED ZMOGLJIVOSTJO V MOČI IN GIBALNO ZMOGLJIVOSTJO V STOJI NA ROKAH: MODEL STROJNEGA UČENJA

The present study investigated the relationship between strength capacity and motor performance in the gymnastic handstand. The hypothesis stipulated a positive relationship between motor performance and strength capacity levels. Thirty-two university students, 16 female and 16 male (24.03 ± 4.74 years of age,) participated in the study. The handstand was assessed using the absolute error of the three angles produced by the model (video) and the three angles produced by the performer. We conducted four strength tests: explosive force, maximum right-hand grip strength, maximum left-hand grip strength, and resistance force. The machine learning model was trained using 10 of the folds and cross-validated, and a linear regression test was performed using motor performance (absolute error) and strength tests (explosive force, maximum force right-hand, maximum force left-hand, and resistance force). The results showed that the machine learning model indicated a low relationship between strength capacity and motor performance. Additionally, motor performance was not found to be related to strength capacity. The results may indicate that specific capacities and the interaction of factors such as task specificity, environment, and individual characteristics influence motor performance.

Dietary intakes and nutritional status in adults with Muscular Dystrophy

Muscular dystrophy (MD) is a group of inherited conditions causing progressive muscle weakness and wasting, for which no widely implementable treatment currently exists, although resistance training (Bostock et al., 2019, Frontiers in Neurology, 10) and corticosteroid treatment (Angelini, 2007, Muscle &amp; Nerve, 36, 424-435), have been shown to improve health-related quality of life (HQoL). Compared to physical activity, dietary manipulation may be more modifiable to improve dystrophic populations HQoL as disease outcomes often restrict physical capabilities. Data exploring the relationship between diet, disease and HQoL outcomes in adults with MD is insufficient. This study evaluated the habitual dietary intake of a sex-inclusive dystrophic population, to identify possible links between dietary intake, HQoL, and physical function. Participants included 5 women (age 65 ± 14 yrs, BMI 23.2 ± 2.7 kg/m2) and 10 men (age 55 ± 19 yrs, 31.6 ± 7.9 kg/m2) with different MDs (varied distribution and severity of muscle weakness). Participants' dietary intake data was collected using 3-day food records: analysed using Nutritics. Dominant hand maximal grip strength was measured using a hand-held dynamometer; upper extremity function and pain were assessed using the upper extremity functional index-15 and visual analogue scale, respectively. QoL was assessed through three tools: SF-36V2, Barthel Index and EQ5D, previously used in dystrophic populations. We observed that 50% of men and 20% of women did not meet the recommended daily intake (RDI) for protein (0.8 g·kg−1), however women (1.13 ± 0.26 g·kg−1) had increased protein intake compared to men (0.82 ± 0.27 g·kg−1, p &lt; 0.05). Of all participants 40% had a daily fat intake exceeding the RDI, with women having significantly higher relative average fat intakes (women = 1.03 ± 0.36 g·kg−1, men = 0.68 ± 0.29 g·kg−1, p &lt; 0.05). RDI for calcium was met by 46% participants (1000 mg) whilst all failed to meet the vitamin D RDI (10 μg). Positive correlations between age and protein intake as a percentage of RDI (r2 = 0.82), protein (r2 = 0.82), carbohydrate intake (r2 = 0.55) relative to body mass, vitamin D intake (r2 = 0.54), and total caloric intake (r2 = 0.59, all p&lt; 0.05) were observed. No other significant associations between dietary habits, physical function or HQoL outcomes were apparent. Despite these findings being observed in a small population it is apparent that many adults with muscular dystrophy may fail to meet RDI for protein, vitamin D, and calcium. This places this population at risk for nutritional deficiencies, incurring negative impacts on the musculoskeletal system. Further study of nutritional status in a larger population sample is needed to confirm these findings.

Task-Oriented Training by a Personalized Electromyography-Driven Soft Robotic Hand in Chronic Stroke: A Randomized Controlled Trial

Background Intensive task-oriented training has shown promise in enhancing distal motor function among patients with chronic stroke. A personalized electromyography (EMG)-driven soft robotic hand was developed to assist task-oriented object-manipulation training effectively. Objective. To compare the effectiveness of task-oriented training using the EMG-driven soft robotic hand. Methods A single-blinded, randomized controlled trial was conducted with 34 chronic stroke survivors. The subjects were randomly assigned to the Hand Task (HT) group (n = 17) or the control (CON) group (n = 17). The HT group received 45 minutes of task-oriented training by manipulating small objects with the robotic hand for 20 sessions, while the CON group received 45 minutes of hand-functional exercises without objects using the same robot. Fugl-Meyer assessment (FMA-UE), Action Research Arm Test (ARAT), Modified Ashworth Score (MAS), Box and Block test (BBT), Maximum Grip Strength, and active range of motion (AROM) of fingers were assessed at baseline, after intervention, and 3 months follow-up. The muscle co-contraction index (CI) was analyzed to evaluate the session-by-session variation of upper limb EMG patterns. Results The HT group showed more significant improvement in FMA-UE (wrist/hand, shoulder/elbow) compared to the CON group (P < .05). At 3-month follow-up, the HT group demonstrated significant improvements in FMA-UE, ARAT, BBT, MAS (finger), and AROMs (P < .05). The HT group exhibited a more significant decrease in muscle co-contractions compared to the CON group (P < .05). Conclusions EMG-driven task-oriented training with the personalized soft robotic hand was a practical approach to improving motor function and muscle coordination. Clinical Trial Registry Name: Soft Robotic Hand System for Stroke Rehabilitation. Clinical Trial Registration-URL: https://clinicaltrials.gov/. Unique Identifier: NCT03286309.

The associations between nutritional status and physical frailty and Alzheimer's disease plasma biomarkers in older cognitively unimpaired adults with positive of amyloid-β PET

Background & AimsIt has been revealed good nutritional status and no physical frailty, which are modifiable lifestyle factors, are linked to less cognitive decline and a lower risk of Alzheimer’s disease (AD). We aimed to investigate the associations between nutritional status and physical frailty and plasma AD biomarkers, especially the Tau-associated biomarkers in older cognitively unimpaired (CU) adults with higher β-amyloid (Aβ) burden. MethodsThe nutritional status and physical frailty were assessed via Mini-Nutritional Assessment Short-Form (MNA-SF) and Fried frailty index. The participants underwent the examination of plasma AD biomarkers and 18F-florbetapir PET scan as well as 18F-MK6240 PET in the validation cohort. Correlation and multiple linear regression analyses were used to investigate the associations between nutritional status and frailty and AD biomarkers. ResultsTwo cohorts were included in our study. A total of 129 participants with Aβ-PET positive were enrolled in the development cohort. Multiple linear regression analysis showed MNA-SF scores, normal nutritional status, Fried frailty index scores, frailty and some domains of frailty including weight loss, maximal grip strength and exhaustion were associated with plasma p-Tau-181. Furthermore, weight loss, Fried frailty index scores and frailty were associated with higher Aβ-PET standard uptake value ratio. We further performed subgroup analyses stratified by age, sex and apolipoprotein E ε4 genotype to investigate the beneficial characteristics of nutrition and frailty in the special subgroups. Validation cohort contained 38 Aβ-PET positive participants. MNA-SF scores, normal nutritional status, Fried frailty index scores and frailty were associated with Tau burden evaluated by 18F-MK6240 PET Braak-like stages. ConclusionsOur data indicates that normal nutritional status and no physical frailty may be associated with expected trend of plasma AD biomarkers, especially less Tau pathology in older CU adults with Aβ deposition. Adjusting to these characteristics of nutrition and physical frailty may help reduce the risk of AD development.

Age- and sex-related changes in motor functions: a comprehensive assessment and component analysis.

Age-related motor impairments often cause caregiver dependency or even hospitalization. However, comprehensive investigations of the different motor abilities and the changes thereof across the adult lifespan remain sparse. We, therefore, extensively assessed essential basic and complex motor functions in 444 healthy adults covering a wide age range (range 21 to 88 years). Basic motor functions, here defined as simple isolated single or repetitive movements in one direction, were assessed by means of maximum grip strength (GS) and maximum finger-tapping frequency (FTF). Complex motor functions, comprising composite sequential movements involving both proximal and distal joints/muscle groups, were evaluated with the Action Research Arm Test (ARAT), the Jebsen-Taylor Hand Function Test (JTT), and the Purdue Pegboard Test. Men achieved higher scores than women concerning GS and FTF, whereas women stacked more pins per time than men during the Purdue Pegboard Test. There was no significant sex effect regarding JTT. We observed a significant but task-specific reduction of basic and complex motor performance scores across the adult lifespan. Linear regression analyses significantly predicted the participants' ages based on motor performance scores (R2 = 0.502). Of note, the ratio between the left- and right-hand performance remained stable across ages for all tests. Principal Component Analysis (PCA) revealed three motor components across all tests that represented dexterity, force, and speed. These components were consistently present in young (21-40 years), middle-aged (41-60 years), and older (61-88 years) adults, as well as in women and men. Based on the three motor components, K-means clustering analysis differentiated high- and low-performing participants across the adult life span. The rich motor data set of 444 healthy participants revealed age- and sex-dependent changes in essential basic and complex motor functions. Notably, the comprehensive assessment allowed for generating robust motor components across the adult lifespan. Our data may serve as a reference for future studies of healthy subjects and patients with motor deficits. Moreover, these findings emphasize the importance of comprehensively assessing different motor functions, including dexterity, force, and speed, to characterize human motor abilities and their age-related decline.

Microstructural neural correlates of maximal grip strength in autistic children: the role of the cortico-cerebellar network and attention-deficit/hyperactivity disorder features.

Maximal grip strength, a measure of how much force a person's hand can generate when squeezing an object, may be an effective method for understanding potential neurobiological differences during motor tasks. Grip strength in autistic individuals may be of particular interest due to its unique developmental trajectory. While autism-specific differences in grip-brain relationships have been found in adult populations, it is possible that such differences in grip-brain relationships may be present at earlier ages when grip strength is behaviorally similar in autistic and non-autistic groups. Further, such neural differences may lead to the later emergence of diagnostic-group grip differences in adolescence. The present study sought to examine this possibility, while also examining if grip strength could elucidate the neuro-motor sources of phenotypic heterogeneity commonly observed within autism. Using high resolution, multi-shell diffusion, and quantitative R1 relaxometry imaging, this study examined how variations in key sensorimotor-related white matter pathways of the proprioception input, lateral grasping, cortico-cerebellar, and corticospinal networks were associated with individual variations in grip strength in 68 autistic children and 70 non-autistic (neurotypical) children (6-11 years-old). In both groups, results indicated that stronger grip strength was associated with higher proprioceptive input, lateral grasping, and corticospinal (but not cortico-cerebellar modification) fractional anisotropy and R1, indirect measures concordant with stronger microstructural coherence and increased myelination. Diagnostic group differences in these grip-brain relationships were not observed, but the autistic group exhibited more variability particularly in the cortico-cerebellar modification indices. An examination into the variability within the autistic group revealed that attention-deficit/hyperactivity disorder (ADHD) features moderated the relationships between grip strength and both fractional anisotropy and R1 relaxometry in the premotor-primary motor tract of the lateral grasping network and the cortico-cerebellar network tracts. Specifically, in autistic children with elevated ADHD features (60% of the autistic group) stronger grip strength was related to higher fractional anisotropy and R1 of the cerebellar modification network (stronger microstructural coherence and more myelin), whereas the opposite relationship was observed in autistic children with reduced ADHD features. Together, this work suggests that while the foundational elements of grip strength are similar across school-aged autistic and non-autistic children, neural mechanisms of grip strength within autistic children may additionally depend on the presence of ADHD features. Specifically, stronger, more coherent connections of the cerebellar modification network, which is thought to play a role in refining and optimizing motor commands, may lead to stronger grip in children with more ADHD features, weaker grip in children with fewer ADHD features, and no difference in grip in non-autistic children. While future research is needed to understand if these findings extend to other motor tasks beyond grip strength, these results have implications for understanding the biological basis of neuromotor control in autistic children and emphasize the importance of assessing co-occurring conditions when evaluating brain-behavior relationships in autism.

The Association Between Grip Strength, Upper Body Power, and Limb Dominance in a Military Population.

Military service members rely on upper body strength and power to accomplish tasks such as carrying heavy weapons and gear, rappelling, combat grappling, and marksmanship. Early identification of the factors that lead to reduced upper body strength and power would enable leadership to predict and mitigate aspects that decrease military operational readiness and increase injury risk. The purpose of this study was to investigate the relationship between grip strength and upper body power in U.S. Infantry Marines. We hypothesized that dominant arm grip strength would show a strong positive correlation with upper body power and that the dominant arm would be more powerful than the non-dominant arm. A total of 120 U.S. Marines completed 3 maximum effort isometric grip strength trials with their dominant hand and 3 maximum effort ballistic pushups on a ForceDecks force plate system. Force plate data were used to estimate pushup height and peak power. Maximum grip strength, pushup height, and peak power across the 3 trials were used for analysis. Pearson's correlation was used to test for associations between peak power, pushup height, and grip strength. Paired t-tests were used to test for differences in peak power between the dominant and non-dominant arms. A very weak correlation was found between grip strength and upper body power, but there was no relationship between grip strength and pushup height. Additionally, there were no significant differences in upper body power between the dominant and non-dominant arms. The results of this study suggest that grip strength is not predictive of upper body power and cannot be used as a stand-alone measure of physical readiness in a military unit. These findings do not, however, degrade the potential of both measures to predict and inform health status and physical readiness. Future prospective research should be conducted to determine if either of these measures can be used as indicators of performance and/or injury susceptibility and if limb dominance plays a role in injury incidence within the upper extremity.

Muscle fibre morphometric analysis (MusMA) correlates with muscle function and cardiovascular risk prognosis.

Morphometry of striated muscle fibres is critical for monitoring muscle health and function. Here, we evaluated functional parameters of skeletal and cardiac striated muscle in two experimental models using the Morphometric Analysis of Muscle Fibre tool (MusMA). The collagen-induced arthritis model was used to evaluate the function of skeletal striated muscle and the non-alcoholic fatty liver disease model was used for cardiac striated muscle analysis. After euthanasia, we used haeamatoxylin and eosin stained sections of skeletal and cardiac muscle to perform muscle fibre segmentation and morphometric analysis. Morphometric analysis classified muscle fibres into six subpopulations: normal, regular hypertrophic, irregular hypertrophic, irregular, irregular atrophic and regular atrophic. The percentage of atrophic fibres was associated with lower walking speed (p = 0.009) and lower body weight (p = 0.026), respectively. Fibres categorized as normal were associated with maximum grip strength (p < 0.001) and higher march speed (p < 0.001). In the evaluation of cardiac striated muscle fibres, the percentage of normal cardiomyocytes negatively correlated with cardiovascular risk markers such as the presence of abdominal adipose tissue (p = .003), miR-33a expression (p = .001) and the expression of miR-126 (p = .042) Furthermore, the percentage of atrophic cardiomyocytes correlated significantly with the Castelli risk index II (p = .014). MusMA is a simple and objective tool that allows the screening of striated muscle fibre morphometry, which can complement the diagnosis of muscle diseases while providing functional and prognostic information in basic and clinical research.

Association of kidney function with physical performance: the Maastricht study.

Kidney failure has been associated with decreased physical capacity, although evidence regarding the physical performance of individuals with earlier stages of chronic kidney disease (CKD)remains limited. Cross-sectional data were derived from the prospective, population-based Maastricht Study. Multivariate linear regression models were fitted to assess the association of estimated glomerular filtration rate (eGFR) and albuminuria categories with physical performance test outcomes. Overall, 7396 participants were included. Compared to eGFR 60-90ml/min/1.73m2, values < 60ml/min/1.73m2 were associated with significantly shorter 6-min walk distance (β: - 13.04m, 95% confidence intervals-CI - 19.95; - 6.13), worse timed chair rise stand test time (β: 0.91s, 95% CI 0.36; 1.47), lower maximal grip (β: - 0.83kg, 95% CI - 1.50; - 0.15) and elbow flexion (β: - 3.64 Nm, 95% CI - 7.11; - 0.16) strength. Additionally, eGFR > 90ml/min/1.73m2 was linked to significantly shorter 6-min walk distance (β: - 6.13m, 95% CI - 9.44; - 2.82). Urinary albumin excretion > 30mg/24h was associated with shorter 6-min walk distance (β: - 12.48m, 95% CI - 18.28; - 6.68), worse timed chair rise stand test time (β: 0.51s, 95% CI 0.11; 1.06), lower maximal grip (β: - 1.34kg, 95% CI - 1.91; - 0.76) and elbow flexion strength (β: - 3.31Nm, 95% CI - 5.80; - 0.82). Reduced eGFR and higher albuminuria levels were associated with worse physical performance, especially shorter 6-min walk distance and lower muscle strength. The relationship between eGFR and physical function was non-linear, with also high eGFR values being associated with worse performance, especially in the six-minute walk test.

Hand Grip and Pinch Strength in a Healthy Children Norms for 6 to 18 Years in Al-Kharj City, Kingdom of Saudi Arabia

Background: Measuring and comparing grip and pinch strengths with their normative data is a valid method to detect intensity of the numerous damages of hand. The aim of the study was to establish the normative data of grip strength and three types of pinch strengths (Key, Tip and Palmar) in healthy Saudi’s children. Method: In this cross-sectional study, of grip strength and three types of pinch strengths (Tip, Key and Palmar) were recorded for 82 healthy children (41 boys and 41 girls) heathy children aged 7-18 years. The Camry Electronic Hand Dynamometer and Hydraulic Pinch Gauge were used to measure grip strength and pinch strength, respectively. Result: Normative data of grip and pinch strengths were provided. Grip and pinch strengths of both genders were close to each other’s and increasing consistently with increasing age. The maximum grip strength and pinch strength was obtained in the group of 14-18 years among both genders. In addition: Study results showed that there was a significant association between weight and all the hand grip strength and pinch strength (p &lt; 0.05) in boys whereas BMI considered as an effective parameter on grip strength and tip pinch strength in girls. Conclusions: Findings from the present study provide reference values for hand grip strength and pinch strength for healthy children from 6- which will be useful to guide rehabilitation outcomes in routine clinical practice.18 years of age which will be useful to guide rehabilitation outcomes in routine clinical practice.

Comparison of two different orthoses used in the treatment of lateral epicondylitis.

Lateral epicondylitis (LE) is one of the most common causes of lateral elbow pain, and orthoses are often used in its conservative treatment. However, the number of studies examining the effectiveness of the orthoses used and their differences compared to each other is limited. To determine the effects of 2 orthoses types, wrist orthosis (WO) and counterforce brace (CB), commonly used in the treatment of lateral epicondylitis on muscle activation, grip strength, hand function, and satisfaction level in healthy individuals. Quasi-experimental study. Thirty-seven healthy individuals were recruited. Muscle activation was evaluated by surface electromyography, and maximum grip strength was evaluated with a handheld dynamometer. Hand function and satisfaction level were evaluated with Jebsen Taylor Hand Function Test and Orthotics and Prosthetics Users Survey, respectively. All evaluations were conducted for each individual in 3 conditions (no orthosis, WO, and CB). Extensor carpi radialis (ECR) muscle activation was greater when using CB compared with that when without orthosis (p = 0.036). There was no significant difference in extensor digitorum communis (EDC) muscle activation and maximum grip strength among the conditions (p > 0.05). Hand function was worse when using the WO compared with the other conditions (p < 0.001). In terms of orthosis satisfaction, individuals were found to be significantly more satisfied with the use of CB (p = 0.001). In our study highlight the use of CB in terms of EDC muscle activity, grip strength, hand function, and satisfaction, while the use of WO is prominent in terms of keeping extensor carpi radialis muscle activity low, which has been shown to be important for LE. To obtain definitive results on the effectiveness of different orthoses in the treatment of LE, more research is needed to compare the muscular activation in the extensor carpi radialis brevis (ECRB) and EDC muscles with objective methods.