Heritability of maximal isometric muscle strength in older female twins

2004 ◽  
Vol 96 (1) ◽  
pp. 173-180 ◽  
Author(s):  
Kristina Tiainen ◽  
Sarianna Sipilä ◽  
Markku Alen ◽  
Eino Heikkinen ◽  
Jaakko Kaprio ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Confidence Interval ◽  
Environmental Effects ◽  
Plantar Flexion ◽  
Knee Extension ◽  
Genetic Component ◽  
Knee Extension Strength ◽  
Muscle Groups ◽  
Flexion Strength ◽  
Ankle Plantar Flexion

The purpose of the present study was to examine genetic and environmental effects on maximal isometric handgrip, knee extension, and ankle plantar flexion strength. In addition, we wanted to investigate whether the strength of these three muscle groups shares a genetic component or whether the genetic effect is specific for each muscle group. Muscle strength was measured as part of the Finnish Twin Study on Aging in 97 monozygotic (MZ) and 102 dizygotic (DZ) female twin pairs, aged 63-76 yr. The MZ and DZ individuals did not differ from each other in age, body height, weight, or self-related health. The age-adjusted pairwise (intraclass) correlations of the MZ and DZ twins were, respectively, 0.462 and 0.242 in knee extension, 0.435 and 0.345 in handgrip, and 0.512 and 0.435 in ankle plantar flexion strength. The multivariate genetic analysis showed that handgrip and knee extension strength shared a genetic component, which accounted for 14% (95% confidence interval: 4-28%) of the variance in handgrip strength and 31% (95% confidence interval: 18-45%) in knee extension strength. The influence of genetic effects on ankle plantar flexion strength was minor and not significant. Furthermore, these three muscle groups had a nongenetic familial effect in common and nonshared environmental effects in common. The results suggested that muscle strength is under a genetic regulation, but also environmental effects have a significant role in explaining the variability in the muscle strength.

scholarly journals Impaired knee extension muscle strength in adolescents but not in children with Fontan circulation

2020 ◽  
Vol 30 (8) ◽  
pp. 1138-1143
Author(s):  
Camilla Sandberg ◽  
Emelie Frisk ◽  
Lena Hansson ◽  
Annika Isberg ◽  
Eva Rylander Hedlund ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Lean Mass ◽  
Plantar Flexion ◽  
Knee Extension ◽  
Fontan Circulation ◽  
Group Level ◽  
Cross Sectional ◽  
Knee Extension Strength ◽  
Isometric Knee Extension ◽  
Isometric Muscle

AbstractIntroduction:Impaired isometric muscle strength was previously reported in adults with Fontan circulation. However, it is unclear if this impairment is present in children and adolescents with Fontan circulation. We investigated isometric muscle strength of the lower limb in patients (6–18 years) with Fontan circulation in comparison with healthy controls.Method:In this cross-sectional study, 43 patients (6–18 years) with Fontan circulation and 43 age- and sex-matched controls were included. Isometric knee extension and plantar flexion muscle strength were assessed using dynamometry (Newton, N). Lean mass of the legs was assessed with dual-energy X-ray absorptiometry. Analyses were performed on group level (n = 43), and for subgroups that included children aged 6–12 years (n = 18) and adolescents aged 13–18 years (n = 25).Results:On group level, the patients with Fontan circulation had impaired isometric knee extension strength in comparison with the controls (p = 0.03). In subgroup analyses, impaired isometric knee extension strength was present in the adolescents (p = 0.009) but not in the children groups. For plantar flexion, there was no difference between patients and controls. There was no difference in lean mass between patients and controls (9.6 ± 4.3 kg vs. 10.8 ± 5.6 kg, p = 0.31). However, the lean mass was highly correlated to isometric knee extension strength (patients r = 0.89, controls r = 0.96, p < 0.001) and isometric plantar flexion strength (patients r = 0.7, controls r = 0.81, p < 0.001).Conclusion:The finding of impaired isometric knee extension muscle strength in adolescents (13–18 years) with Fontan circulation and no corresponding impairment in the children group (6–12 years) could imply that isometric muscle strength gets more impaired with age.

scholarly journals Military Protein Intake Related to Strength and Fat Mass Independent of Energy Intake

2020 ◽  
Vol 185 (9-10) ◽  
pp. e1671-e1678
Author(s):  
Jeremy A Ross ◽  
D Travis Thomas ◽  
Joshua D Winters ◽  
Scott D Royer ◽  
Christopher J Halagarda ◽  
...  
Keyword(s):  
Energy Intake ◽  
Body Mass ◽  
Knee Flexion ◽  
Protein Intake ◽  
Performance Metrics ◽  
Knee Extension ◽  
Special Operations ◽  
Knee Extension Strength ◽  
Peak Knee ◽  
Flexion Strength

ABSTRACT Introduction Kinetic military units operate in austere training environments and deprivation not commonly experienced by competitive athletes. Nutritional strategies to protect against decrements in performance and potential injury risk may differ for these two groups. A cross sectional analysis was conducted to determine energy and macronutrient characteristics associated with performance metrics. Materials and Methods 78 male subjects (age: 28.4 ± 6.0 years, height: 178.3 ± 6.7 cm, mass: 84.3 ± 9.4 kg, 8.5 ± 5.8 years of service) assigned to Marine Corps Forces Special Operations Command completed a 1-day performance assessment. Body mass, lean body mass, fat mass (FM), aerobic capacity (VO2max), lactate inflection point (LT), anaerobic power, anaerobic capacity, knee flexion strength, knee extension strength, peak knee flexion strength, and peak knee extension strength outcome values were recorded. Dietary intake was collected using automated self-administered 24-hour dietary recall (ASA24). Performance assessment scores were compared with macronutrient intake and controlled for energy intake using analysis of covariance. Results Differences in knee flexion strength, knee extension strength, peak knee flexion strength, and peak knee extension strength were significant across low (LPRO), medium (MPRO), and high (HPRO) protein intake groups (p &lt; 0.05) with LPRO performance metrics significantly lower than both MPRO and HPRO and MPRO significantly lower than HPRO. FM was significantly higher in LPRO than MPRO or HPRO (p &lt; 0.05). Low carbohydrate intake (LCHO) was associated with greater body mass and FM compared with high (HCHO) (p &lt; 0.05). There was no association between fat intake and any variable. Conclusions Increases in protein intake may have beneficial performance effects independent of total energy intake, while moderate increases in carbohydrate intake may not be sufficient to enhance physical performance in a special operations population.

scholarly journals Effect of vitamin D fortified foods on bone markers and muscle strength in women of Pakistani and Danish origin living in Denmark: a randomised controlled trial

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Ida M. Grønborg ◽  
Inge Tetens ◽  
Elisabeth Wreford Andersen ◽  
Michael Kristensen ◽  
Rikke E. K. Larsen ◽  
...  
Keyword(s):  
Vitamin D ◽  
Muscle Strength ◽  
Bone Turnover ◽  
Bone Turnover Markers ◽  
Bone Markers ◽  
Knee Extension ◽  
Fortified Foods ◽  
Knee Extension Strength ◽  
Turnover Markers

Abstract Background Deficient and insufficient vitamin D status (defined as serum 25(OH)D < 30 nmol/L and > 50 nmol/L) is prevalent worldwide and associated with decreased muscle strength and poor bone health. We aimed to investigate the effect of vitamin D fortification on bone markers and muscle strength among younger adult women at risk of vitamin D deficiency. Methods A 12-week randomised double-blinded placebo-controlled winter intervention trial, providing 30 μg vitamin D3/day through fortified yoghurt, cheese, eggs and crisp-bread or similar placebo products. Participants were 143 women of Danish and Pakistani origin 18–50 years of age, living in Denmark, randomised into four groups stratified by ethnicity. Serum 25-hydroxyvitamin D (25(OH)D) by LC-MS/MS and the secondary endpoints: four specific bone markers (osteocalcin (OC), Bone specific Alkaline Phosphatase (BALP), Procollagen type 1 amino-terminal propeptide (P1NP), C-terminal crosslinked telopeptide of type 1 collagen (CTX)) and three muscle strength measures (handgrip, knee extension strength, chair-standing), were assessed using one-way ANOVA, Tukey HSD and subsequent linear ANCOVA models, adjusted for relevant covariates. Results Significantly increased serum 25(OH)D concentration from 53.3 (17) to 77.8 (14) nmol/L and from 44.5 (21) to 54.7 (18) nmol/L among Danish and Pakistani women in the fortified groups, respectively (P <  0.05). The bone turnover markers OC, BALP, P1NP and CTX did not change significantly. Muscle strength by handgrip, knee extension and chair-standing test did not change significantly following the intervention. Conclusions Consumption of vitamin D fortified foods for 12 weeks did not result in significant changes of the bone turnover markers OC, BALP, P1NP and CTX. Muscle strength measured as hand grip strength, knee extension strength and chair-standing did not change significantly following the intervention.

scholarly journals Comparison of quadriceps setting strength and knee extension strength tests to evaluate lower limb muscle strength based on health-related physical fitness values in elderly people

2020 ◽  
Vol 6 (1) ◽  
pp. e000753
Author(s):  
Yuki Ito ◽  
Takumi Aoki ◽  
Takeru Sato ◽  
Kan Oishi ◽  
Kojiro Ishii
Keyword(s):  
Muscle Strength ◽  
Physical Fitness ◽  
Grip Strength ◽  
Lower Limb ◽  
Knee Extension ◽  
Walking Distance ◽  
Lower Limb Muscle ◽  
Limb Muscle ◽  
Knee Extension Strength ◽  
Health Related

ObjectiveConventionally, knee extension strength is often used as the indicator for lower limb muscle strength; however, several recent studies have also used quadriceps setting strength. This study aimed to investigate and compare the association of quadriceps setting and knee extension strength with health-related physical fitness.MethodsWe evaluated quadriceps setting strength and isometric knee extension strength in 75 elderly subjects (mean age, 76.8±5.3 years) to determine their lower limb muscle strength. Health-related physical fitness was evaluated using the physical fitness test advocated by the Ministry of Education and Culture, Sports, Science and Technology in Japan. The test consists of the following components: grip strength, sit-up, sit and reach, one leg standing with eyes open, 10 m obstacle walk and 6 min walk.ResultsWhen adjusted for age, sex and body mass index, quadriceps setting strength was significantly correlated with grip strength, number of sit-ups, sit and reach distance, 10 m obstacle walking time and 6 min walking distance. In contrast, knee extension strength was associated only with grip strength and number of sit-ups.ConclusionMore health-related physical fitness parameters with quadriceps setting strength than knee extension strength. Quadriceps setting strength may be superior to knee extension strength as a predictor of health-related physical fitness.

scholarly journals Daily 30-min exposure to artificial gravity during 60 days of bed rest does not maintain aerobic exercise capacity but mitigates some deteriorations of muscle function: results from the AGBRESA RCT

2021 ◽  
Author(s):  
Andreas Kramer ◽  
María Venegas-Carro ◽  
Jochen Zange ◽  
Wolfram Sies ◽  
Nicola A. Maffiuletti ◽  
...  
Keyword(s):  
Aerobic Exercise ◽  
Exercise Capacity ◽  
Muscle Function ◽  
Plantar Flexion ◽  
Bed Rest ◽  
Knee Extension ◽  
Artificial Gravity ◽  
Knee Extension Strength ◽  
Aerobic Exercise Capacity ◽  
Group Time

Abstract Purpose Spaceflight impairs physical capacity. Here we assessed the protective effect of artificial gravity (AG) on aerobic exercise capacity and muscle function during bed rest, a spaceflight analogue. Methods 24 participants (33 ± 9 years, 175 ± 9 cm, 74 ± 10 kg, 8 women) were randomly allocated to one of three groups: continuous AG (cAG), intermittent AG (iAG) or control (CTRL). All participants were subjected to 60 days of six-degree head-down tilt bed rest, and subjects of the intervention groups completed 30 min of centrifugation per day: cAG continuously and iAG for 6 × 5 min, with an acceleration of 1g at the center of mass. Physical capacity was assessed before and after bed rest via maximal voluntary contractions, cycling spiroergometry, and countermovement jumps. Results AG had no significant effect on aerobic exercise capacity, flexor muscle function and isometric knee extension strength or rate of force development (RFD). However, AG mitigated the effects of bed rest on jumping power (group * time interaction of the rmANOVA p < 0.001; iAG − 25%, cAG − 26%, CTRL − 33%), plantar flexion strength (group * time p = 0.003; iAG − 35%, cAG − 31%, CTRL − 48%) and plantar flexion RFD (group * time p = 0.020; iAG − 28%, cAG − 12%, CTRL − 40%). Women showed more pronounced losses than men in jumping power (p < 0.001) and knee extension strength (p = 0.010). Conclusion The AG protocols were not suitable to maintain aerobic exercise capacity, probably due to the very low cardiorespiratory demand of this intervention. However, they mitigated some losses in muscle function, potentially due to the low-intensity muscle contractions during centrifugation used to avoid presyncope.

Protein Intake and Physical Performance Following Long-Term Stay on the International Space Station

2021 ◽  
Vol 92 (3) ◽  
pp. 153-159
Author(s):  
Yuko Nozawa ◽  
Yukiko Wagatsuma
Keyword(s):  
Physical Performance ◽  
Protein Intake ◽  
Plantar Flexion ◽  
Space Station ◽  
Knee Extension ◽  
Carbohydrate Intake ◽  
International Space ◽  
Exercise Effect ◽  
Ankle Plantar Flexion

INTRODUCTION: Exposure to microgravity reduces muscle mass, volume, and performance. The ingestion of protein, especially combined with carbohydrate intake and exercise after ingestion, improves net muscle protein synthesis and increases muscle mass. However, there are few studies on this relationship during and after a long-term spaceflight. The objective of this study was to investigate the influence of protein and the combined effects of carbohydrate intake on muscle performance following long-term spaceflight.METHODS: This study is a retrospective cohort study involving secondary analysis of data stored in the NASA Lifetime Surveillance of Astronaut Health Repository. Multivariable analysis was performed to evaluate the impact of protein intake on physical performance by considering covariates potentially associated with each model.RESULTS: After adjusting for sex, age, flight week, energy intake, and preflight physical performance, protein intake was found to be significantly associated with concentric measurements for knee extension ( 51.66), ankle plantar flexion ( 32.86), and eccentric measurements for ankle plantar flexion ( 79.85) at 5 d after landing. Significant associations remained after controlling for exercise effect. No significant interaction between protein and carbohydrate intake was observed in either model.DISCUSSION: Protein intake during spaceflight was related to physical performance for knee extension and ankle plantar flexion, even after taking exercise effect into consideration. However, protein and carbohydrate intake provided no synergetic benefit. This suggests that high protein intake, about twice the current average intake, may serve as a countermeasure to offset the negative effects of long-duration spaceflights.Nozawa Y, Wagatsuma Y. Protein intake and physical performance following long-term stay on the International Space Station. Aerosp Med Hum Perform. 2021; 92(3):153159.

scholarly journals Evaluation of the Criterion-related Validity of Ankle Plantar Flexion Strength Measurement

2013 ◽  
Vol 28 (6) ◽  
pp. 741-744
Author(s):  
Yoshihiro KAI ◽  
Shin MURATA ◽  
Masayuki SOMA ◽  
Yasuhiko TAMORI ◽  
Miwako FUJITA ◽  
...  
Keyword(s):  
Plantar Flexion ◽  
Strength Measurement ◽  
Flexion Strength ◽  
Ankle Plantar Flexion

Electromyographic and Safety Comparisons of Common Lower Limb Rehabilitation Exercises for People With Hemophilia

2019 ◽  
Author(s):  
Joaquín Calatayud ◽  
Sofía Pérez-Alenda ◽  
Juan J Carrasco ◽  
Adrián Escriche-Escuder ◽  
Carlos Cruz-Montecinos ◽  
...  
Keyword(s):  
Lower Limb ◽  
Muscle Activity ◽  
Plantar Flexion ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Activity Levels ◽  
External Resistance ◽  
Elastic Resistance ◽  
Ankle Plantar Flexion ◽  
Gastrocnemius Lateralis

Abstract Background Ankles and knees are commonly affected in people with hemophilia and thus are targets for prevention or rehabilitation. However, to our knowledge, no studies have evaluated muscle activity and safety during exercises targeting the lower limbs in people with hemophilia; this lack of information hinders clinical decision-making. Objective The aim of this study was to compare the tolerability of, safety of, and muscle activity levels obtained with external resistance (elastic or machine)–based and non–external resistance–based lower limb exercises in people with hemophilia. Design This was a cross-sectional study. Methods Eleven people who had severe hemophilia and were undergoing prophylactic treatment participated. In a single experimental session, participants performed knee extension and ankle plantar flexion during 3 exercise conditions in random order: elastic band–based resistance (elastic resistance), machine-based resistance (machine resistance), and no external resistance. Exercise intensities for the 2 external resistance–based conditions were matched for perceived exertion. Muscle activity was determined using surface electromyography (EMG) for the rectus femoris, biceps femoris, gastrocnemius lateralis, and tibialis anterior muscles. Participants were asked to rate exercise tolerability according to a scale ranging from “very well tolerated” to “not tolerated” and to report possible adverse effects 24 and 48 hours after the session. Results No adverse effects were reported, and exercise tolerability was generally high. In the knee extension exercise, the rectus femoris normalized EMG values during the elastic resistance and machine resistance conditions were similar; 29% to 30% higher activity was obtained during these conditions than during the non–external resistance condition. In the ankle plantar flexion exercise, the gastrocnemius lateralis normalized EMG value was 34% higher during the machine resistance condition than without external resistance, and the normalized EMG values during the elastic resistance and other conditions were similar. Limitations The small sample size and single training session were the primary limitations of this study. Conclusions Exercises performed both with elastic bands and with machines at moderate intensity are safe, feasible, and efficient in people with severe hemophilia, providing comparable activity levels in the agonist muscles.

The effect of ankle flexibility on the relationship between knee isokinetic strength and the speed of underwater dolphin kicks in male competitive swimmers

2021 ◽  
pp. 1-8
Author(s):  
Yupeng Shen ◽  
Yanqing Fu ◽  
Yu Ge ◽  
Yuhong Wen
Keyword(s):  
Muscle Strength ◽  
Plantar Flexion ◽  
Knee Extensor ◽  
Isokinetic Strength ◽  
Knee Flexor ◽  
Lower Extremity Muscle ◽  
The Relationship ◽  
Competitive Swimmers ◽  
Ankle Flexibility ◽  
Ankle Plantar Flexion

BACKGROUND: Lower-extremity muscle strength and ankle flexibility play key roles in underwater swimming movements. OBJECTIVES: To investigate the relationship between knee isokinetic strength and the speed of underwater dolphin kicks (UDK-S) in competitive male swimmers and identify whether ankle flexibility affects the association between knee isokinetic strength and UDK-S. METHODS: Fifty-two highly trained male swimmers participated in this study. The speed at which the participants travelled 15 m performing UDKs was calculated as UDK-S. Knee flexor and extensor concentric isokinetic strength at fast (240∘/s) and slow (60∘/s) velocities and ankle flexibility were evaluated. Bayesian framework analysis was conducted to examine the relationship between these variables and determine whether this relationship is influenced by ankle flexibility. RESULTS: There was strong-to-extremely strong evidence (Bayes factor = 24.4 to 198.3) that knee extensor (60∘/s) and knee flexor (60∘/s and 240∘/s) strength are positively and generally moderately correlated with UDK-S. Ankle plantar flexion flexibility was identified to be a moderator between knee extensor strength (60∘/s) and UDK-S. CONCLUSIONS: Knee extensor and knee flexor strength were significantly correlated with UDK-S, and the relationship between knee muscle strength and UDK-S was influenced by ankle plantar flexion flexibility in male competitive swimmers.

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