Maximal Handgrip Strength Research Articles

Relationship between Pulse Pressure and Handgrip Strength in the Korean Population: A Nationwide Cross-Sectional Study.

Background: Sarcopenia is defined as the loss of muscle mass and strength and low physical performance, and it is closely related to the risk of cardiovascular disease and mortality. Pulse pressure (PP) is a biomarker of arterial stiffness and compliance. Elevated PP levels increase the risk of cardiovascular diseases and all-cause mortality. Nevertheless, the association between PP and sarcopenia has not yet been clearly established. Methods: Participant data were extracted from the Korea National Health and Nutrition Examination Survey conducted from 2014 to 2020. The study population was classified into three groups (PP < 40 mmHg, 40 mmHg ≤ PP < 60 mmHg, and PP ≥ 60 mmHg). PP was calculated by deducting the diastolic blood pressure from the systolic blood pressure. For handgrip strength, the maximum value measured with a grip dynamometer was adopted (weak handgrip strength: <28 kg for men, <18 kg for woman; normal handgrip strength: ≥28 kg for men, ≥18 kg for women). To determine the relationship between PP and the prevalence of weak handgrip strength, multiple logistic regression analysis was performed after adjusting for possible confounding factors. Results: The higher PP group had a higher age, body mass index; systolic blood pressure, prevalence of hypertension, diabetes, hyperlipidemia, and metabolic syndrome, and maximum handgrip strength. In all models, the prevalence of weak handgrip strength was significantly higher in the group with PP ≥ 60 mmHg compared to the control group (PP < 40 mmHg). Conclusions: Elevated PP was significantly associated with a higher prevalence of weak muscle strength. Thus, PP monitoring may be used to identify individuals at risk of sarcopenia and is helpful in improving health outcomes.

Effect of Mirror Therapy on Post-Needling Pain Following Deep Dry Needling of Myofascial Trigger Point in Lateral Elbow Pain: Prospective Controlled Pilot Trial.

Background: This prospective randomized, controlled pilot trial to explore the immediate effect of adding Mirror Visual Feedback Therapy on pain sensitivity and motor performance among subjects suffering from post-needling pain diagnosed as Lateral Elbow Pain. Methods: A total of 49 participants (23 female, 26 male) were enrolled and randomly allocated to either the experimental group, which received Deep Dry Needling in the m. Brachioradialis, Ischemic Compression, Cold Spray, Stretching, and Mirror Visual Feedback Therapy (n = 25), or a control group without Mirror Visual Feedback Therapy (n = 24). Pre- and post-treatment evaluations included assessments of post-needling pain intensity, pressure pain threshold, two-point discrimination threshold, and maximum hand grip strength. Results: Intergroup analysis revealed a statistically significant reduction in post-needling pain intensity favoring the experimental group (U = 188.00, p = 0.034). Additionally, intragroup analysis showed significant improvements in post-needling pain intensity (MD = 0.400, SEM = 0.271, W = 137.00, p = 0.047) and pressure pain threshold (MD = 0.148 Kg/cm2, SEM = 0.038, W = 262.00, p < 0.001) within the experimental group following the intervention. Conclusions: These findings suggest a potential benefit of integrating Mirror Visual Feedback Therapy into treatment protocols for individuals with Lateral Elbow Pain experiencing post-needling discomfort. Further research is necessary to fully elucidate the clinical implications of these findings.

Association between Handgrip strength weakness and asymmetry with incident hip fracture among older Chinese adults

BackgroundTo evaluate the association between handgrip strength (HGS) weakness and asymmetry with incident hip fracture among older Chinese adults. MethodsData was obtained from the 2011 and 2015 waves of the China Health and Retirement Longitudinal Study (CHARLS). HGS weakness was defined as maximal HGS < 28 kg in men and < 18 kg in women. HGS asymmetry was defined as the HGS ratio < 0.9 or > 1.1. Participants were categorized into normal HGS, weakness only, asymmetry only, and both weakness and asymmetry. Given the sex differences in HGS, the association between HGS weakness and asymmetry was analyzed by sex using the multivariable logistic regression models. ResultsA total of 4789 participants aged ≥ 60 years old without hip fracture at baseline were included in the final analysis. Over the four-year follow-up, there were 152 (3.17%) participants having incident hip fractures, of which 69 (2.90%) were men and 83 (3.45%) were women. Compared to the normal group, men with both weakness and asymmetry had a significantly higher risk of incident hip fracture in the fully adjusted model (adjusted odds ratio (OR): 2.31, 95% confidence interval (CI):1.17-4.52). There was no significant association between HGS asymmetry and weakness with hip fracture in women. ConclusionsOur findings indicated that among the Chinese population, men with both HGS weakness and asymmetry were associated with increased odds of hip fracture, while no significant association was observed in women.

Health-related fitness in medical students: a curricular intervention in Bogota, Colombia

ObjectiveTo evaluate the impact of a curricular intervention to promote health-related fitness (HRF) among medical students in Bogota, Colombia.MethodThe study was conducted between May 2014 and December 2015 as part of the medical physiology course, in which 208 medical students were enrolled.The curricular intervention included two lectures on physical activity (PA) and student-led group presentations on the physiological effects of exercise on human physiology. An academic incentive (10% of final grade) was given to students who reported and documented regular PA practice during the semester. This study assessed students’ HRF variables, perceptions of the curriculum intervention, and PA practices using quantitative and qualitative approaches.Results55% of the students were female, with a mean age of 19.5 years. Body fat, estimated maximum oxygen consumption (VO2max), handgrip, and sit-up strength showed statistically significant improvements at the end of the intervention. Students reported that PA practice was positively influenced by the curriculum intervention, particularly the academic incentive and the HRF tests. Students reported a wide variety of PA practices, which were mainly done with friends, classmates, or family members. Lack of time was the main reported barrier to PA practice.ConclusionThe curricular intervention was effective in improving HRF and promoting PA. It remains to be investigated whether these gains are sustained over time.

Association Between Dietary Fiber Intake and Low Muscle Strength Among Korean Adults.

The health benefits of dietary fiber are widely recognized, but its impact on muscle health remains unclear. Therefore, this study aimed to elucidate the relationship between dietary fiber intake and muscle strength through a cross-sectional analysis of data from the Korea National Health and Examination Survey (KNHANES). Data from a single 24-h dietary recall and handgrip strength tests of 10,883 younger adults aged 19 to 64 years and 3,961 older adults aged ≥ 65 years were analyzed. Low muscle strength was defined as handgrip strength < 28 kg for men and < 18 kg for women. Multivariable linear and logistic regression analyses were conducted to determine the association of dietary fiber intake with muscle strength. Approximately 43% of Korean adults met the recommended intake of dietary fiber, and those with higher dietary fiber consumption also had higher total energy and protein intake. After adjusting for confounding variables, dietary fiber intake was found to be positively associated with maximal handgrip strength in younger women aged 19 to 64 years (β = 0.015; standard error [SE] = 0.006) and older men aged ≥ 65 years (β = 0.035; SE = 0.014). For older women aged ≥ 65 years, those in the lowest quartile of dietary fiber intake had a higher risk of low muscle strength than those in the highest quartile after adjustment of confounders (odds ratio 1.709; 95% confidence interval 1.130-2.585). These results suggest that adequate dietary fiber intake may reduce the risk of sarcopenia in older Korean women.

Effects of a pulmonary rehabilitation program on pulmonary function, exercise performance, and quality of life in patients with severe COVID-19.

Severe coronavirus 2019 disease (COVID-19) causes acute hypoxemic respiratory failure requiring invasive mechanical ventilation (IMV). Once these symptoms are resolved, patients can present systemic deterioration. The two objectives of this study were as follows: to describe the results of a pulmonary rehabilitation program (PRP), which is divided into three groups with different numbers of sessions (12, 24, and 36), and to associate the variables of pulmonary function, exercise performance, and functionality with the number of sessions and functional improvement. Prospective, observational study. PRP consisted of aerobic + strength + flexibility exercises under the supervision and individualized into 12, 24, or 36 sessions (12s, 24s, and 36s), depending on the evolution of each patient. At the beginning of the study and immediately after the intervention, forced vital capacity (FVC), maximal inspiratory pressure, 6-minute walk test (6MWT), sit-to-stand test (STS), maximal handgrip strength (HGS), Fatigue Assessment Scale, Post-COVID-19 Functional Status (PCFS), and health-related quality of life (HRQoL) were measured. The proposed PRP demonstrated a positive effect on pulmonary function, exercise performance, and HRQoL, regardless of the number of sessions. A higher score on the PCFS and more days on IMV were associated with the increased likelihood of needing more sessions, whereas more meters on the 6MWT in the initial evaluation was associated with a reduced likelihood of needing more sessions. Finally, more repetitions on the STS and less distance covered on the initial 6MWT were associated with a greater improvement in exercise performance evaluated with the 6MWT. Supervised and individualized PRP for patients with severe post-COVID-19 improves pulmonary function, exercise performance, functionality, and quality of life. Functionality, distance covered on the 6MWT, and the days on IMV are central to the scheduling of the number of sessions for these patients.

Quantitative and qualitative evaluation of the masseter muscle by ultrasonography and correlation with whole body health status.

[Purpose] Ultrasonography can be used to non-invasively analyze any cross-section of the human body and to measure tissue elasticity, thickness, and brightness. This study was performed to examine the quantitative and qualitative changes in the masseter muscle at rest and at maximal occlusion, and to evaluate the relationship between these changes and the general health of the individual. [Participants and Methods] The study cohort comprised 30 healthy adults. Correlations between basic participant information (sex, age, height, body weight, body mass index, body fat, maximum bite force, handgrip strength, and tongue pressure) and masseter muscle ultrasonographic data were examined. [Results] Masseter muscle thickness was significantly greater in males than in females. Body weight and body mass index correlated positively with masseter muscle thickness. Body mass index and body fat percentage correlated positively with masseter muscle brightness. Tongue pressure correlated positively with handgrip strength. [Conclusion] Our analyses of muscle thickness and brightness suggest that ultrasonography may be useful in evaluating masseter muscle quantity and quality, and that the condition of the masseter muscle may correlate with the overall health status of the individual.

A Study of Handgrip Strength in the South Indian Male Population

Background: The anatomical system of the hand is complex and includes both static and moving parts. For the most part of our lives, we take our grip strength for granted. It is necessary to preserve the integrity of the handgrip and provides information regarding general muscle strength, endurance, and power. Handgrip strength can also serve as a straightforward, cost-effective, and practical tool in occupational health research; it can be used to assess nutritional status, track the loss of muscle strength, and develop prevention or intervention measures. The present study aimed to compare maximal hand grip strength in men of different age groups. Materials and methods: 150 male subjects in total, whose ages ranged from 20 to 60, participated in the study. Subjects in the age group of 40–60 years were taken as Group I, and those in the age group of 20–39 years were taken as Group II. The strength of the dominant hand's grip was compared between the two groups in the current study. The grip strength of the dominant hand was measured three times at an interval of 1 minute, and the mean value recorded was considered to be the maximum hand grip strength. The data was analyzed by paired t tests using SPSS version 22. Results: The handgrip strength in males aged 20–39 years was statistically significant (p &lt; 0.001) as compared to the other group. Conclusion: Handgrip strength is higher in younger males when compared to men over 40, probably due to increased muscle mass. Keywords: hand grip strength, hand dynamometer, male

Moderate selenium mitigates hand grip strength impairment associated with elevated blood cadmium and lead levels in middle-aged and elderly individuals: insights from NHANES 2011-2014.

Background: Selenium (Se) has been reported to have an antagonistic effect on heavy metals in animals. Nevertheless, there is a lack of epidemiological research examining whether Se can mitigate the adverse effects of cadmium (Cd) and lead (Pb) on hand grip strength (HGS) in middle-aged and elderly individuals. Methods: This study used data from the 2011-2014 National Health and Nutrition Examination Survey (NHANES). HGS measurements were conducted by trained examiners with a dynamometer. Concentrations of Se, Cd, and Pb in blood were determined via inductively coupled plasma mass spectrometry. We employed linear regression, restricted cubic splines, and quantile g-computation (qgcomp) to assess individual and combined associations between heavy metals and HGS. The study also explored the potential influence of Se on these associations. Results: In both individual metal and multi-metal models adjusted for confounders, general linear regression showed Se's positive association with HGS, while Cd and Pb inversely related to it. At varying Se-Cd and Se-Pb concentrations, high Se relative to low Se can attenuate Cd and Pb's HGS impact. An inverted U-shaped correlation exists between Se and both maximum and combined HGS, with Se's benefit plateauing beyond approximately 200μg/L. Stratified analysis by Se quartiles reveals Cd and Pb's adverse HGS effects diminishing as Se levels increase. Qgcomp regression analysis detected Se alleviating HGS damage from combined Cd and Pb exposure. Subsequent subgroup analyses identified the sensitivity of women, the elderly, and those at risk of diabetes to HGS impairment caused by heavy metals, with moderate Se supplementation beneficial in mitigating this effect. In the population at risk for diabetes, the protective role of Se against heavy metal toxicity-induced HGS reduction is inhibited, suggesting that diabetic individuals should particularly avoid heavy metal-induced handgrip impairment. Conclusion: Blood Cd and Pb levels are negatively correlated with HGS. Se can mitigate this negative impact, but its effectiveness plateaus beyond 200μg/L. Women, the elderly, and those at risk of diabetes are more vulnerable to HGS damage from heavy metals. While Se supplementation can help, its protective effect is limited in high diabetes risk groups.

Energy and nutrient intake in older adults with healthy aging during the Corona Virus Disease 19 pandemic– a cohort study

Background and objectiveLockdown measures implemented amid the COVID-19 pandemic promoted changes in lifestyle, particularly engagement in physical activity/exercise and dietary intake. However, few studies are available investigating the healthy older population, particularly in developing countries. Therefore, the objective of this study was to assess the impact of the COVID-19 pandemic on energy and nutrient intake among older adults with successful aging and to evaluate changes in muscle mass, strength and physical performance. MethodsA cohort study of 38 healthy older adults from a Brazilian geriatrics referral center were assessed at two time points: baseline – up to 1 year prior to the pandemic; and follow-up – an average of 17 months after the pandemic outbreak. Energy and nutrient intake was determined using food recalls and diary records, while muscle mass was calculated based on anthropometric parameters. Maximum hand-grip strength and Short Physical Performance Battery (SPPB) score were also evaluated. ResultsMedian age of participants was 87 years. During the pandemic, intake of protein increased from 52.6g to 63.9g (p=0.013) and micronutrients also increased: vitamin C from 35.4 mg to 76.1mg (p=0.027), vitamin B12 from 2.2mg to 3.1 mg (p=0.045), calcium from 435.1mg to 631.5mg (p<0.001), magnesium from 186.5mg to 198.9 mg (p=0.043), zinc from 5.8 mg to 7.6 mg (p=0.009), iron from 6.9mg to 7.2 mg (p=0.035) and potassium from 1941.6mg to 2115.5 mg (p=0.048). No changes in energy intake or other nutrients were evident. No difference in mass, strength or physical performance was observed during the study period. Overall, 84% of participants remained physically active, although engagement in physical exercise decreased by 50% (p<0.002). ConclusionThe increase in intake of proteins and micronutrients suggests improved diet quality during the pandemic. Engagement in physical exercise decreased significantly, but level of physical activity was maintained. No change in anthropometric parameters, strength or physical performance was evident in the population investigated.

Trial in Progress: Investigating the Prognostic Significance of Malnutrition and Sarcopenia in Older Adults with Acute Myeloid Leukemia

Background and Significance: For older adults (≥60 years) newly diagnosed with acute myeloid leukemia (AML), tumor-specific and patient-specific factors have been used to predict treatment-related mortality (TRM) and determine suitability for intensive antileukemic therapy. Comprehensive Geriatric Assessment (CGA) is a tool designed to comprehensively evaluate health among older adults. CGA assesses multiple health domains including physical function, cognition, nutrition, mental health, polypharmacy, comorbidities, and social support but does not currently incorporate body imaging. Sarcopenia is defined as loss of muscle mass and strength. It can be measured objectively by CT, DEXA or Bioimpedance Analysis (BIA) in combination with tests of muscle strength. It has been proposed as a more accurate nutritional marker compared to BMI or serum markers. Nearly all older adults with AML receive a CT scan during their cancer evaluation. Therefore, there is an opportunity to leverage CT sarcopenia measures to improve risk prediction. Our study aims to (1) assess the burden of malnutrition and sarcopenia in older adults with newly diagnosed AML undergoing induction and (2) determine the prognostic impact of traditional markers of nutrition and novel sarcopenia measures on TRM. Study Design and Methods: This is a prospective, observational study of 82 newly diagnosed, older adult patients with AML undergoing induction treatment at the University of Chicago Comprehensive Cancer Center (NCT05458258). Key inclusion criteria include age ≥60 years and receipt of induction therapy for newly diagnosed AML. Key exclusion criteria include presence of a pacemaker or defibrillator. To assess Aim 1, newly diagnosed older adult patients with AML will be undergo a subjective global nutrition assessment and serum nutritional markers [prealbumin, albumin, CRP, ferritin]. Body composition (fat-mass, fat-free mass, lean mass) will be assessed using BIA and CT. Sarcopenia will be defined by the CT Skeletal Muscle Index (SMI) at L3 plus impairment on either maximal hand grip strength, 6-minute walk, Timed Up and Go test (TUG), the Short Physical Performance Battery (SPPB). Patients will also undergo an assessment of disability (instrumental activities of daily living (IADL) and activities of daily living (ADL) surveys), Short Physical Performance Battery [SPPB], and Montreal cognitive assessment [MOCA]) prior to starting induction. All measures will be repeated at the start of post-remission therapy. Results from both timepoints will be compared against healthy controls matched by age, sex and Charlson Comorbidity Index. Healthy control data will come from the Frailty, Activity, Body Composition, and Energy Expenditure (FACE) Aging dataset housed by the Department of Geriatrics at the University of Chicago, a 1-year longitudinal, observation study of frailty in older adults residing around the university. We will match 1 AML case to 1 control. In order to ensure that all subjects are matched, 2:1 propensity score matching will be used to generate matching controls for each case. To assess Aim 2, multivariable Cox proportional hazards regression models will be performed for each of those nutrition status and sarcopenia markers significant for TRM in univariate analysis. In multivariable analyses, we will control for age, European Leukemia Net 2022 risk stratification, ECOG PS, and CGA measures as covariates. A sample size of 82 patients will give us 80% power to detect a hazard ratio of 3.0 for TRM, the primary end point, for CT diagnosed sarcopenia using a Cox proportional hazards model with a 0.05 significance level and a 60-day mortality rate of 18%. We anticipate completion of enrollment within two years of study initiation. To date, 17 patients have been approached for consent with 11 patients enrolled. When complete, this trial will provide initial evidence necessary to recommend nutritional assessment as a part of the Comprehensive Geriatric Assessment in all older adult AML patients. Furthermore, it may provide evidence to support a future interventional study assessing the impact of improved nutritional status on TRM. Figure 1. NCT05458258 study schema.

Effects of measurement protocols and repetitions on handgrip strength weakness and asymmetry in patients with cancer.

The use of handgrip strength (HGS) in clinical cancer research is surging. The association between HGS and outcomes in patients with cancer varied across studies, which might be due to the different measurement protocols for HGS. We aimed to answer three questions: (1) Did the use of various protocols for HGS, along with different numbers of repetitions, lead to significant differences in maximum HGS values? (2) If yes, were these differences clinically significant? (3) Did the differences in HGS protocols and repetitions affect the identification of HGS weakness or HGS asymmetry? We continuously recruited adult patients with solid tumours. Two protocols were used to measure HGS: Method A, following the American Society of Hand Therapists guidelines, and Method B, following the National Health and Nutrition Examination Survey guidelines. To analyse HGS, we used the maximal value obtained from either two or three repetitions of the dominant hand or four or six repetitions of both hands. We included 497 patients (326 men and 171 women, median age: 58years). The maximal HGS values, measured with Method B, were significantly higher than those measured by Method A in both men and women, despite repetitions (all P<0.05). The maximum HGS values were significantly different across the repetition groups, regardless of measurement protocols and sex (all P<0.01). The protocol-induced differences in maximal HGS values might be clinically meaningful in over 60% of men and 40% of women despite repetitions. The repetition-induced difference was only clinically significant in 4.3-17.8% of men and 4.1-14.6% of women. To identify HGS weakness, using Method A (six repetitions) as the 'gold' standard, the other protocols demonstrated an overall accuracy of 0.923-0.997 in men and 0.965-1 in women. To identify HGS asymmetry, using Method A (six repetitions) as the 'gold' standard, Method B (six repetitions) demonstrated a diagnostic accuracy of 0.972 in men and 0.971 in women. Method A (four repetitions) showed a diagnostic accuracy of 0.837 in men and 0.825 in women, while Method B (four repetitions) showed a diagnostic accuracy of 0.825 in men and 0.807 in women. Both measurement protocols and repetitions significantly affect the maximal HGS values. The identification of HGS weakness is not significantly affected by either protocols or repetitions, while the identification of HGS asymmetry may be affected by different repetitions but not protocols.

Combinatorial Effects of Transcutaneous Spinal Stimulation and Task-Specific Training to Enhance Hand Motor Output after Paralysis.

Despite the positive results in upper limb (UL) motor recovery after using electrical neuromodulation in individuals after cervical spinal cord injury (SCI) or stroke, there has been limited exploration of potential benefits of combining task-specific hand grip training with transcutaneous electrical spinal stimulation (TSS) for individuals with UL paralysis. This study investigates the combinatorial effects of task-specific hand grip training and noninvasive TSS to enhance hand motor output after paralysis. Four participants with cervical SCI classified as AIS A and B and two participants with cerebral stroke were recruited in this study. The effects of cervical TSS without grip training and during training with sham stimulation were contrasted with hand grip training with TSS. TSS was applied at midline over cervical spinal cord. During hand grip training, 5 to 10 seconds of voluntary contraction were repeated at a submaximum strength for approximately 10 minutes, three days per week for 4 weeks. Signals from hand grip dynamometer along with the electromyography (EMG) activity from UL muscles were recorded and displayed as visual feedback. Our case study series demonstrated that combined task-specific hand grip training and cervical TSS targeting the motor pools of distal muscles in the UL resulted in significant improvements in maximum hand grip strength. However, TSS alone or hand grip training alone showed limited effectiveness in improving grip strength. Task-specific hand grip training combined with TSS can result in restoration of hand motor function in paralyzed upper limbs in individuals with cervical SCI and stroke.

Lower handgrip strength in short-sleeper individuals with obstructive sleep apnea

BackgroundObstructive sleep apnea (OSA) is a frequently observed and remarkably incapacitating disorder worldwide. As a multisystem disorder, OSA has been linked to a plethora of clinical parameters though physical parameters like muscle strength have been scantily studied. Hand grip strength (HGS) is a practical marker of physical function that has been associated with mortality and an array of clinical outcomes as well as physiological parameters like sleep duration. A few seminal studies have observed no link between HGS and OSA severity while no studies evaluated the relationship between objectively determined sleep duration and HGS in OSA. ObjectiveThe present study aimed to evaluate the HGS indices among both OSA severity groups and objectively determined sleep duration groups in OSA. Methods111 treatment-naïve mostly middle-aged individuals with OSA (86 males) were recruited in a tertiary sleep center. Three OSA severity groups were determined by the Apnea-Hypopnea Index while three sleep duration groups were objectively determined by Total Sleep Time (TST). Dominant and non-dominant maximum and average HGS were calculated using a digital hand dynamometer. ResultsShort-sleeper individuals with OSA were found to have lower HGS indices than intermediate or sufficient sleepers with OSA while no differences in HGS indices among OSA severity groups were observed. All HGS indices correlated with TST. ConclusionsFuture insights can be gleaned from the present results regarding the conceivably transdiagnostic relationship between sleep duration and HGS as well as the potential use of HGS as a marker in OSA.

Handgrip strength assessment at baseline in addition to bone parameters could potentially predict the risk of curve progression in adolescent idiopathic scoliosis.

Adolescent idiopathic scoliosis (AIS) is characterized by deranged bone and muscle qualities, which are important prognostic factors for curve progression. This retrospective case-control study aims to investigate whether the baseline muscle parameters, in addition to the bone parameters, could predict curve progression in AIS. The study included a cohort of 126 female patients diagnosed with AIS who were between the ages of 12 and 14 years old at their initial clinical visit. These patients were longitudinally followed up every 6 months (average 4.08 years) until they reached skeletal maturity. The records of these patients were thoroughly reviewed as part of the study. The participants were categorized into two sub-groups: the progressive AIS group (increase in Cobb angle of ≥6°) and the stable AIS group (increase in Cobb angle <6°). Clinical and radiological assessments were conducted on each group. Cobb angle increase of ≥6° was observed in 44 AIS patients (34.9%) prior to skeletal maturity. A progressive AIS was associated with decreased skeletal maturity and weight, lower trunk lean mass (5.7%, p = 0.027) and arm lean mass (8.9%, p < 0.050), weaker dominant handgrip strength (8.8%, p = 0.027), deranged cortical compartment [lower volumetric bone mineral density (vBMD) by 6.5%, p = 0.002], and lower bone mechanical properties [stiffness and estimated failure load lowered by 13.2% (p = 0.005) and 12.5% (p = 0.004)]. The best cut-off threshold of maximum dominant handgrip strength is 19.75 kg for distinguishing progressive AIS from stable AIS (75% sensitivity and 52.4% specificity, p = 0.011). Patients with progressive AIS had poorer muscle and bone parameters than patients with stable AIS. The implementation of a cut-off threshold in the baseline dominant handgrip strength could potentially be used as an additional predictor, in addition to bone parameters, for identifying individuals with AIS who are at higher risk of experiencing curve progression.

A machine learning-based scoring system and ten factors associated with hip fracture occurrence in the elderly.

Hip fractures are fragility fractures frequently seen in persons over 80-years-old. Although various factors, including decreased bone mineral density and a history of falls, are reported as hip fracture risks, few large-scale studies have confirmed their relevance to individuals older than 80, and tools to assess contributions of various risks to fracture development and the degree of risk are lacking. We recruited 1395 fresh hip fracture patients and 1075 controls without hip fractures and comprehensively evaluated various reported risk factors and their association with hip fracture development. We initially constructed a predictive model using Extreme Gradient Boosting (XGBoost), a machine learning algorithm, incorporating all 40 variables and evaluated the model's performance using the area under the receiver operating characteristic curve (AUC), yielding a value of 0.87. We also employed SHapley Additive exPlanation (SHAP) values to evaluate each feature importance and ranked the top 20. We then used a stepwise selection method to determine key factors sequentially until the AUC reached a plateau nearly equal to that of all variables and identified the top 10 sufficient to evaluate hip fracture risk. For each, we determined the cutoff value for hip fracture occurrence and calculated scores of each variable based on the respective feature importance. Individual scores were: serum 25(OH)D levels (<10ng/ml, score 7), femoral neck T-score (<-3, score 5), Barthel index score (<100, score 3), maximal handgrip strength (<18kg, score 3), GLFS-25 score (≥24, score 2), number of falls in previous 12months (≥3, score 2), serum IGF-1 levels (<50ng/ml, score 2), cups of tea/day (≥5, score -2), use of anti-osteoporosis drugs (yes, score -2), and BMI (<18.5kg/m2, score 1). Using these scores, we performed receiver operating characteristic (ROC) analysis and the resultant optimal cutoff value was 7, with a specificity of 0.78, sensitivity of 0.75, and AUC of 0.85. These ten factors and the scoring system may represent tools useful to predict hip fracture.

Gender-specific moderating role of abdominal obesity in the relationship between handgrip strength and cognitive impairment

Both low handgrip strength (HGS) and abdominal obesity (AO) are associated with cognitive impairment. However, it remains unclear whether low HGS and AO interact to affect cognition, and whether the synergistic effect varies by gender. This study aimed to examine whether the association between low HGS and incident cognitive impairment was moderated by AO among Chinese older men and women. We used the data of participants (≥60 years) from four waves (2011-2018) of the China Health and Retirement Longitudinal Study. We defined low HGS as the maximal HGS of <28kg in men and <18kg in women, and AO as waist circumference of ≥90cm for men and ≥80cm for women. Cognitive impairment was defined as a global cognitive score in the lowest 10th percentile. For each gender, we used subdistribution hazards model to estimate subdistribution hazard ratios (SHRs) for the association of low HGS and AO with incident cognitive impairment, treating mortality as the competing event and controlling for other covariates. Multiplicative interaction was assessed through a cross-product interaction term of low HGS and AO in the model. Additive interaction between low HGS and AO was evaluated by calculating the relative excess risk due to interaction (RERI) and attributable proportion due to interaction (AP). We included 3704 participants (Mean age: 66.9±5.81; 54.9% male). During the 7-year follow-up, 1133 events of interest occurred (731 cognitive impairments and 402 deaths). Incidence rates of cognitive impairment and mortality were 4.1 (95% CI: 3.8 to 4.4) and 2.2 (95% CI: 2.0 to 2.5) per 100 person-years. There were positive multiplicative (SHR for the product term=1.974, 95% CI: 1.114 to 3.500) and additive interactions (RERI=1.056, 95% CI: 0.027 to 2.086, AP=0.454, 95% CI: 0.158 to 0.750) of low HGS and AO on the risk of cognitive impairment among older men. Male participants with both low HGS and AO showed an increased risk of cognitive impairment (SHR=2.325, 95% CI: 1.498 to 3.609) compared with those without either. There was no evidence of interaction among older women (SHR for the product term=1.151, 95% CI: 0.725 to 1.825; RERI=0.044, 95% CI:-0.524 to 0.613; AP=0.039, 95% CI:-0.458 to 0.536). Low HGS and AO may interact to synergistically increase the risk of cognitive impairment among Chinese older men. Screening the highest-risk subpopulation, who may benefit most from neurocognitive prevention strategies, may maximize potential public health gains.

Interlimb Asymmetry of Maximal Handgrip Strength and Wrist Circumference in Elite International Male Boxers

The purpose of the study was to examine interlimb maximal handgrip strength asymmetry and wrist circumference asymmetry in amateur boxing across three weight classes and two different stances. Materials and methods. The study sample comprised 12 (flyweight:4; bantamweight:4; featherweight:4) amateur elite international boxers of India. Both limbs were tested for maximal handgrip strength and wrist circumference. For both tests, interlimb asymmetry was calculated using the interlimb asymmetry equation validated by Bishop et al. (2018). One-way ANOVA was used to compare asymmetries in three different weight classes, and an independent samples t-test was used to compare asymmetries in two different boxing stances. Results. The average wrist circumference asymmetry in different weight classes was 2.85±1.97 for flyweight, 1.29±0.75 for bantamweight, and 2.44±1.23 for featherweight, whereas the average maximal handgrip strength asymmetry was 4.91±3.75 for flyweight, 7.69±1.89 for bantamweight, and 5.80±2.89 for featherweight. Non-significant differences in interlimb asymmetry for wrist circumference and maximal handgrip strength in three different weight classes and two different stances were obtained (p &gt; 0.05). Conclusions. The maximal handgrip strength asymmetry and wrist circumference asymmetry in elite international boxers were found to be less than 10 percent and observed non-significant differences in weight classes as well as stances indicate elite amateur international boxers to be less prone to interlimb asymmetry-related injuries and have favourable conditions for high performance.

Skeletal muscle mass, muscle strength, and physical performance in children and adolescents with obesity.

Sarcopenic obesity (SO) is defined as obesity with low skeletal muscle function and mass. This study aimed to evaluate the presence of sarcopenic obesity according to different diagnostic criteria and assess the elements of sarcopenia in children and adolescents with obesity. A total of 95 children and adolescents with obesity (diagnosed with the use of International Obesity Task Force (IOTF) criteria) with a mean age of 12.7( ± 3) years participated in the study. Body composition was assessed with the use of bioelectrical impedance-BIA (Tanita BC480MA) and dual-energy X-ray absorptiometry-DXA (Hologic). Fat mass (FM) and appendicular skeletal muscle mass (SMMa) were expressed as kilograms (kg) and percentage (%). Muscle-to-fat ratio (MFR) was defined as SMMa divided by FM. A dynamometer was used in order to measure grip strength. Six-minute walk test (6MWT) and a timed up-and-go test (TUG) were used to assess physical performance. The presence of SO ranged from 6.32% to 97.89%, depending on the criteria used to define sarcopenia. Children with sarcopenia, defined as a co- occurrence of low skeletal muscle mass % (SMM%) measured by DXA (≤9th centile) according to McCarthy et al. and weak handgrip strength (≤10th centile) according to Dodds et al., had significantly lower SMMa measured by both DXA and BIA, lower maximal handgrip strength, and lower physical performance. Maximal handgrip was positively correlated with SMMa (kg) and SMMa% derived from both DXA and BIA and BIA-MFR. Maximal handgrip was negatively correlated with waist-to-height ratio (WHtR). The distance of 6MWT correlated positively with BIA-measured SMMa% and BIA-MFR. 6MWT distance correlated negatively with BIA-FM% and body mass index (BMI) z-score. TUG was positively correlated with BIA-FM%, BMI z-score, WHtR, and IOTF categories and negatively correlated with BIA-SMMa% and BIA-MFR. The presence of sarcopenia in our study varied depending on the diagnostic criteria used. This is one of the first studies evaluating muscle mass, muscle strength, and physical performance in children and adolescents with obesity. The study highlighted the need for the implementation of a consensus statement regarding SO diagnostic criteria in children and adolescents.

Endurance Exercise Performance Is Reduced after 6-h Dives at 1.35 ATA When Breathing 100% Oxygen Compared with Air.

Long-duration dives on consecutive days reduces muscular performance, potentially affecting military personnel. However, a paucity of data exists on how breathing gases affect endurance performance. This study examined the influence of long-duration diving with different breathing gases on aerobic endurance and handgrip performance. Twenty-three military divers completed a single 6-h dive (single dive [SD]) and five 6-h dives over consecutive days (dive week [DW]) with 30-min cycling intervals using air (AIR, n = 13) or 100% oxygen (OXY, n = 10). Before and after SD and DW, subjects completed a maximum handgrip strength test, a handgrip endurance test at 40% maximal strength, and a time to exhaustion run. Handgrip endurance decreased after DW in OXY (SD, 1.9 ± 0.0 vs 1.4 ± 0.3 min) compared with AIR (1.8 ± 0.0 vs 1.8 ± 0.2 min) ( P < 0.001). Run time decreased after SD (Pre, 20.7 ± 10.4 min; Post, 16.6 ± 7.6 min; P = 0.039) and DW (Pre, 21.6 ± 9.0 min; Post, 11.2 ± 4.0 min; P < 0.001) in OXY and after overall diving in AIR (Pre, 26.5 ± 10.2 min; Post, 22.3 ± 7.5 min; P = 0.025). V̇O 2 decreased after diving only in AIR (Pre, 42.6 ± 3.4 mL·kg -1 ⋅min -1 ; Post, 40.4 ± 3.7 mL·kg -1 ⋅min -1 ; P = 0.010). There were no other significant effects. Breathing 100% oxygen during long-duration dives on consecutive days may exacerbate decreases in aerobic endurance and impairs handgrip endurance compared with air. Additional research is needed to elucidate mechanisms of action and possible mitigation strategies.