Grgic, Jozo; Mikulic, Pavle
The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean ± SD: age = 26 ± 6 years, stature = 182 ± 9 cm, body mass = 84 ± 9 kg, resistance training experience = 7 ± 3 years) consumed placebo or 6 mg kg -1 of anhydrous caffeine 1 h before testing. Muscular power was assessed with seated medicine ball throw and vertical jump exercises, muscular strength with one-repetition maximum (1RM) barbell back squat and bench press exercises, and muscular endurance with repetitions of back squat and bench press exercises (load corresponding to 60% of 1RM) to momentary muscular failure. RPE and PP were assessed immediately after the completion of the back squat and bench press exercises. Compared to placebo, caffeine intake enhanced 1RM back squat performance (+2.8%; effect size [ES] = 0.19; p = .016), which was accompanied by a reduced RPE (+7%; ES = 0.53; p = .037), and seated medicine ball throw performance (+4.3%, ES = 0.32; p = .009). Improvements in 1RM bench press were not noted although there were significant (p = .029) decreases in PP related to this exercise when participants ingested caffeine. The results point to an acute benefit of caffeine intake in enhancing lower-body strength, likely due to a decrease in RPE; upper-, but not lower-body power; and no effects on muscular endurance, in resistance-trained men. Individuals competing in events in which strength and power are important performance-related factors may consider taking 6 mg kg -1 of caffeine pre-training/competition for performance enhancement.
Rosenburg, Beth S.; And Others
A study determined if anaerobic power, isometric strength, and isometric endurance are affected by the menstrual cycle and if endurance trained females and untrained females are affected in the same manner on these performance parameters. Subjects were healthy, normally menstruating females, ages 18-34 years who were classified as either trained…
Hackett, Daniel A.; Davies, Timothy B.; Ibel, Denis; Cobley, Stephen; Sanders, Ross
This study examined the predictive ability of the medicine ball chest throw and vertical jump for muscular strength and power in adolescents. One hundred and ninety adolescents participated in this study. Participants performed trials of the medicine ball chest throw and vertical jump, with vertical jump peak power calculated via an estimation…
Full Text Available The present study determined the effects of muscular endurance strength training on maximum strength and power, functional capacity, muscle activation and hypertrophy in older men and women. Eighty-one men and women acted as an intervention group while 22 acted as non-training controls (age range 64–75 y. Intervention training included super-sets (i.e., paired exercises, immediately performing the second exercises following completion of the first with short rest intervals (30–60 s between sets at an intensity of 50–60% one-repetition maximum (1-RM for 15–20 repetitions. Concentric leg press actions measured maximum strength (1-RM and concentric peak power. Functional capacity was assessed by maximum speed walking tests (i.e., forward walk, backward walk, timed-up-and-go, and stair climb tests. Quadriceps muscle activation was assessed by surface electromyogram and twitch interpolation technique. Vastus lateralis cross-sectional area was measured by panoramic ultrasound. Compared to control, the intervention groups increased maximum strength (1-RM; men: 10 ± 7% vs. 2 ± 3%, women: 14 ± 9% vs. 1 ± 6% both P < 0.01 and vastus lateralis cross-sectional area (men: 6 ± 7% vs. −3 ± 6%, women: 10 ± 10% vs. 0 ± 4% both P < 0.05. But there were no between-group differences in peak power, muscle activation or functional capacity (e.g., stair climb; men: −5 ± 7% vs. −4 ± 3%, women: −5 ± 6% vs. −2 ± 5% both P > 0.05. While benefits occurred during muscular endurance strength training, specific stimuli are probably needed to target all aspects of age-related health.
Suchomel, Timothy J; Nimphius, Sophia; Bellon, Christopher R; Stone, Michael H
This review covers underlying physiological characteristics and training considerations that may affect muscular strength including improving maximal force expression and time-limited force expression. Strength is underpinned by a combination of morphological and neural factors including muscle cross-sectional area and architecture, musculotendinous stiffness, motor unit recruitment, rate coding, motor unit synchronization, and neuromuscular inhibition. Although single- and multi-targeted block periodization models may produce the greatest strength-power benefits, concepts within each model must be considered within the limitations of the sport, athletes, and schedules. Bilateral training, eccentric training and accentuated eccentric loading, and variable resistance training may produce the greatest comprehensive strength adaptations. Bodyweight exercise, isolation exercises, plyometric exercise, unilateral exercise, and kettlebell training may be limited in their potential to improve maximal strength but are still relevant to strength development by challenging time-limited force expression and differentially challenging motor demands. Training to failure may not be necessary to improve maximum muscular strength and is likely not necessary for maximum gains in strength. Indeed, programming that combines heavy and light loads may improve strength and underpin other strength-power characteristics. Multiple sets appear to produce superior training benefits compared to single sets; however, an athlete's training status and the dose-response relationship must be considered. While 2- to 5-min interset rest intervals may produce the greatest strength-power benefits, rest interval length may vary based an athlete's training age, fiber type, and genetics. Weaker athletes should focus on developing strength before emphasizing power-type training. Stronger athletes may begin to emphasize power-type training while maintaining/improving their strength. Future research should
Chen, Chee Keong; Hamdan, Nor Faeiza; Ooi, Foong Kiew; Wan Abd Hamid, Wan Zuraida
This study investigated the effects of Lignosus rhinocerotis (LRS) supplementation and resistance training (RT) on isokinetic muscular strength and power, anaerobic and aerobic fitness, and immune parameters in young males. Participants were randomly assigned to four groups: Control (C), LRS, RT, and combined RT-LRS (RT-LRS). Participants in the LRS and RT-LRS groups consumed 500 mg of LRS daily for 8 weeks. RT was conducted 3 times/week for 8 weeks for participants in the RT and RT-LRS groups. The following parameters were measured before and after the intervention period: Anthropometric data, isokinetic muscular strength and power, and anaerobic and aerobic fitness. Blood samples were also collected to determine immune parameters. Isokinetic muscular strength and power were increased ( P anaerobic power and capacity and aerobic fitness in this group. Similarly, RT group had increases ( P anaerobic power and capacity, aerobic fitness, T lymphocytes (CD3 and CD4), and B lymphocytes (CD19) counts were observed in the RT group. RT elicited increased isokinetic muscular strength and power, anaerobic and aerobic fitness, and immune parameters among young males. However, supplementation with LRS during RT did not provide additive benefits.
Marsh Anthony P
Full Text Available Abstract Background Although progressive resistance strength training (ST has been found to improve various measures of physical functioning in older adults, the benefit to quality of life is unclear. Additionally, recent evidence suggests that high velocity power training (PT may be more beneficial for physical functioning than ST, but it is not known whether this type of training impacts quality of life. The purpose of this study was to compare changes in multiple measures of quality of life resulting from ST vs. PT in older adults. A no exercise group was also included as control comparison condition. Methods Forty-five older adults (M age = 74.8 years; SD = 5.7 were randomly assigned to either a PT, b ST, or c control group (no exercise. Measures of self-efficacy (SE, satisfaction with physical function (SPF, and the Satisfaction with Life Scale (SWL were assessed at baseline and following training. The resistance training conditions met 3 times per week for 12 weeks at an intensity of 70% 1 repetition maximum. Results A series of ANCOVA's comparing between group differences in change and controlling for baseline values revealed significant group differences in all three measures: SE (F(2,31 = 9.77; p (2,32 = 3.36; p = .047; SWL (F(2,31 = 4.76; p = .016. Follow up analyses indicated that the PT group reported significantly more change in SE, SPF, and SWL than the control group whereas the ST group reported greater change than the control group only in SE. Conclusion These pilot data indicate that high velocity power training may influence multiple levels of quality of life over and above the benefits gained through traditional strength training.
Sökmen, Bülent; Witchey, Ronald L; Adams, Gene M; Beam, William C
Sökmen, B, Witchey, RL, Adams, GM, and Beam, WC. Effects of sprint interval training with active recovery vs. endurance training on aerobic and anaerobic power, muscular strength, and sprint ability. J Strength Cond Res 32(3): 624-631, 2018-This study compared sprint interval training with active recovery (SITAR) to moderate-intensity endurance training (ET) in aerobic and anaerobic power, muscular strength, and sprint time results. Forty-two recreationally active adults were randomly assigned to a SITAR or ET group. Both groups trained 3× per week for 10 weeks at 75% of V[Combining Dot Above]O2max for 30 minutes weeks 1-4, with duration increasing to 35 minutes weeks 5-7 and 40 minutes weeks 8-10. While ET ran on a 400-m track without rest for the full training session, SITAR sprinted until the 200-m mark and recovered with fast walking or light jogging the second 200 m to the finish line in 3× original sprint time. Maximal oxygen consumption (V[Combining Dot Above]O2max), anaerobic treadmill run to exhaustion at 12.5 km·h at 20% incline, isokinetic leg extension and flexion strength at 60 and 300°·s, and 50 m sprint time were determined before and after training. Results showed a significant improvement (p ≤ 0.05) in absolute and relative V[Combining Dot Above]O2max, anaerobic treadmill run, and sprint time in both groups. Only SITAR showed significant improvements in isokinetic leg extension and flexion at 300°·s and decreases in body mass (p ≤ 0.05). SITAR also showed significantly greater improvement (p ≤ 0.05) over ET in anaerobic treadmill run and 50 m sprint time. These data suggest that SITAR is a time-efficient strategy to induce rapid adaptations in V[Combining Dot Above]O2max comparable to ET with added improvements in anaerobic power, isokinetic strength, and sprint time not observed with ET.
van der Kooi, EL; Vogels, OJM; van Asseldonk, RJGP; Lindeman, E; Hendriks, JCM; Wohlgemuth, M; van der Maarel, SM; Padberg, GW
Background: In animals and healthy volunteers beta2-adrenergic agonists increase muscle strength and mass, in particular when combined with strength training. In patients with facioscapulohumeral muscular dystrophy (FSHD) albuterol may exert anabolic effects. The authors evaluated the effect of
Maslow, Andréa L; Sui, Xuemei; Colabianchi, Natalie; Hussey, Jim; Blair, Steven N
The protective effects of cardiorespiratory fitness (CRF) on hypertension (HTN) are well known; however, the association between muscular strength and incidence of HTN has yet to be examined. This study evaluated the strength-HTN association with and without accounting for CRF. Participants were 4147 men (age = 20-82 yr) in the Aerobics Center Longitudinal Study for whom an age-specific composite muscular strength score was computed from measures of a one-repetition maximal leg and a one-repetition maximal bench press. CRF was quantified by maximal treadmill exercise test time in minutes. Cox proportional hazards regression analysis was used to estimate hazard ratios (HR) and 95% confidence intervals of incident HTN events according to exposure categories. During a mean follow-up of 19 yr, there were 503 incident HTN cases. Multivariable-adjusted (excluding CRF) HR of HTN in normotensive men comparing middle- and high-strength thirds to the lowest third were not significant at 1.17 and 0.84, respectively. Multivariable-adjusted (excluding CRF) HR of HTN in baseline prehypertensive men comparing middle- and high-strength thirds to the lowest third were significant at 0.73 and 0.72 (P = 0.01 each), respectively. The association between muscular strength and incidence of HTN in baseline prehypertensive men was no longer significant after control for CRF (P = 0.26). The study indicated that middle and high levels of muscular strength were associated with a reduced risk of HTN in prehypertensive men only. However, this relationship was no longer significant after controlling for CRF.
President's Council on Physical Fitness and Sports, Washington, DC.
This paper begins by defining the terms "weight training,""weight lifting,""strength,""power," and "muscular endurance.""Weight training" is differentiated from "weight lifting" and defined as a systematic series of resistance exercises designed to promote physical development and conditioning or to rehabilitate persons who have suffered injury or…
Brown, Niklas; Bubeck, Dieter; Haeufle, Daniel F B; Weickenmeier, Johannes; Kuhl, Ellen; Alt, Wilfried; Schmitt, Syn
Detailed description of the time course of muscular adaptation is rarely found in literature. Thus, models of muscular adaptation are difficult to validate since no detailed data of adaptation are available. In this article, as an initial step toward a detailed description and analysis of muscular adaptation, we provide a case report of 8 weeks of intense strength training with two active, male participants. Muscular adaptations were analyzed on a morphological level with MRI scans of the right quadriceps muscle and the calculation of muscle volume, on a voluntary strength level by isometric voluntary contractions with doublet stimulation (interpolated twitch technique) and on a non-voluntary level by resting twitch torques. Further, training volume and isokinetic power were closely monitored during the training phase. Data were analyzed weekly for 1 week prior to training, pre-training, 8 weeks of training and 2 weeks of detraining (no strength training). Results show a very individual adaptation to the intense strength training protocol. While training volume and isokinetic power increased linearly during the training phase, resting twitch parameters decreased for both participants after the first week of training and stayed below baseline until de-training. Voluntary activation level showed an increase in the first 4 weeks of training, while maximum voluntary contraction showed only little increase compared to baseline. Muscle volume increased for both subjects. Especially training status seemed to influence the acute reaction to intense strength training. Fatigue had a major influence on performance and could only be overcome by one participant. The results give a first detailed insight into muscular adaptation to intense strength training on various levels, providing a basis of data for a validation of muscle fatigue and adaptation models.
Olga E. Aftimichuk; Alexander V. Varvarich
Muscular imbalance is one of the manifestations of pathological-biomechanical changes in muscular-skeletal system. It is the result of tonus-power imbalance of short and relaxed muscles. Muscle shortening is the most striking sign of muscular imbalance. Hypodynamia and passive lifestyle can cause such results. The paper justifies the experimental technique of women muscular imbalances correction by means of power training. Selection of exercises, weights and machines was made, taking into acc...
BURNHAM, STAN; MCCRAW, LYNN W.
A STUDY WAS CONCERNED WITH A COMPARISON OF ISOTONIC, ISOMETRIC, AND SPEED EXERCISE PROGRAMS AS A MEANS OF DEVELOPING MUSCLE STRENGTH, ENDURANCE, SPEED, AND POWER. SUBJECTS FOR THE INVESTIGATION WERE 93 FRESHMEN AND SOPHOMORE MEN ENROLLED IN A PHYSICAL EDUCATION CLASS. AFTER MEASUREMENT OF INITIAL STATUS IN THE ATTRIBUTES UNDER CONSIDERATION, THE…
Rutherford, O M
Strength training is commonly used in the rehabilitation of muscles atrophied as a result of injury and/or disuse. Studies on the effects of conventional leg extension training in healthy subjects have shown the changes to be very task-specific to the training manoeuvre itself. After conventional leg extension training for the quadriceps muscle the major improvement was in weightlifting ability with only small increases in isometric strength. The maximum dynamic force and power output during sprint cycling showed no improvement. These results suggest that the major benefit of this type of training is learning to coordinate the different muscle groups involved in the training movement rather than intrinsic increases in strength of the muscle group being trained. Other studies have shown changes in strength to be specific to the length and speed at which the muscle has been trained. The implication for rehabilitation is that strength training for isolated muscle groups may not be the most effective way of increasing functional ability. As the major changes are task-specific it may be better to incorporate the training into task-related practice. This would have the advantage of strengthening the muscle groups affected whilst increasing performance in those activities which are required in daily life.
Ciccolo, Joseph T; SantaBarbara, Nicholas J; Dunsiger, Shira I; Busch, Andrew M; Bartholomew, John B
Muscular strength is a well-known predictor of morbidity and mortality. Similarly, self-esteem is a predictor of health and well-being. The relationship between these two variables, however, is currently unknown. This study examined the cross-sectional relationship between maximal muscular strength (i.e. handgrip and one-repetition-maximum (1-RM) squat) and global self-esteem in 126 college students. Significant correlations were found between both measures of muscular strength and self-esteem. Further analyses revealed that these relationships were only significant for men. Based on these results, additional research is needed to further explore the relationship between muscular strength and self-esteem, especially in other demographic groups and longitudinally. © The Author(s) 2015.
Sahlberg, M.; Svantesson, U.; Magnusson, Thomas E.
Physical training is important in the treatment of patients with cystic fibrosis (CF). Optimal types of training and intensity are unknown. The aim of the study was to evaluate the effect on muscular strength after 6 months of endurance training (ET) and/or resistance training (RT). Twenty patients....... Vitamin E and cytokines were analyzed. Fifteen tests of muscular strength were used. Handgrip strength in females and quadriceps strength in males were significantly decreased compared with healthy age- and sex-matched controls and positively associated with lung function. Sixteen patients completed...
Aadahl, Mette; Beyer, Nina; Linneberg, Allan
To assess muscular fitness by hand grip strength (HGS) and lower limb extension power (LEP) and to explore associations with age, leisure time physical activity (LTPA) and body composition.......To assess muscular fitness by hand grip strength (HGS) and lower limb extension power (LEP) and to explore associations with age, leisure time physical activity (LTPA) and body composition....
Crewther, Blair; Cronin, John; Keogh, Justin
The metabolic response to resistance exercise, in particular lactic acid or lactate, has a marked influence upon the muscular environment, which may enhance the training stimulus (e.g. motor unit activation, hormones or muscle damage) and thereby contribute to strength and power adaptation. Hypertrophy schemes have resulted in greater lactate responses (%) than neuronal and dynamic power schemes, suggesting possible metabolic-mediated changes in muscle growth. Factors such as age, sex, training experience and nutrition may also influence the lactate responses to resistance exercise and thereafter, muscular adaptation. Although the importance of the mechanical and hormonal stimulus to strength and power adaptation is well recognised, the contribution of the metabolic stimulus is largely unknown. Relatively few studies for example, have examined metabolic change across neuronal and dynamic power schemes, and not withstanding the fact that those mechanisms underpinning muscular adaptation, in relation to the metabolic stimulus, remain highly speculative. Inconsistent findings and methodological limitations within research (e.g. programme design, sampling period, number of samples) make interpretation further difficult. We contend that strength and power research needs to investigate those metabolic mechanisms likely to contribute to weight-training adaptation. Further research is also needed to examine the metabolic responses to different loading schemes, as well as interactions across age, sex and training status, so our understanding of how to optimise strength and power development is improved.
Vaara, Jani P; Kyröläinen, Heikki; Niemi, Jaakko; Ohrankämmen, Olli; Häkkinen, Arja; Kocay, Sheila; Häkkinen, Keijo
The purpose of the present study was to assess the relationships between maximal strength and muscular endurance test scores additionally to previously widely studied measures of body composition and maximal aerobic capacity. 846 young men (25.5 ± 5.0 yrs) participated in the study. Maximal strength was measured using isometric bench press, leg extension and grip strength. Muscular endurance tests consisted of push-ups, sit-ups and repeated squats. An indirect graded cycle ergometer test was used to estimate maximal aerobic capacity (V(O2)max). Body composition was determined with bioelectrical impedance. Moreover, waist circumference (WC) and height were measured and body mass index (BMI) calculated. Maximal bench press was positively correlated with push-ups (r = 0.61, p strength (r = 0.34, p strength correlated positively (r = 0.36-0.44, p test scores were related to maximal aerobic capacity and body fat content, while fat free mass was associated with maximal strength test scores and thus is a major determinant for maximal strength. A contributive role of maximal strength to muscular endurance tests could be identified for the upper, but not the lower extremities. These findings suggest that push-up test is not only indicative of body fat content and maximal aerobic capacity but also maximal strength of upper body, whereas repeated squat test is mainly indicative of body fat content and maximal aerobic capacity, but not maximal strength of lower extremities.
Crump, Casey; Sundquist, Jan; Winkleby, Marilyn A; Sundquist, Kristina
Low physical fitness and obesity have been associated with higher risk of developing heart failure (HF), but their interactive effects are unknown. Elucidation of interactions among these common modifiable factors may help facilitate more effective primary prevention. We conducted a national cohort study to examine the interactive effects of aerobic fitness, muscular strength and body mass index (BMI) among 1 330 610 military conscripts in Sweden during 1969-1997 (97%-98% of all 18-year-old men) on risk of HF identified from inpatient and outpatient diagnoses through 2012 (maximum age 62 years). There were 11 711 men diagnosed with HF in 37.8 million person-years of follow-up. Low aerobic fitness, low muscular strength and obesity were independently associated with higher risk of HF, after adjusting for each other, socioeconomic factors, other chronic diseases and family history of HF. The combination of low aerobic fitness and low muscular strength (lowest vs highest tertiles) was associated with a 1.7-fold risk of HF (95% CI 1.6 to 1.9; pfitness, low muscular strength and obesity at the age of 18 years were independently associated with higher risk of HF in adulthood, with interactive effects between aerobic fitness and muscular strength. These findings suggest that early-life interventions may help reduce the long-term risk of HF and should include both aerobic fitness and muscular strength, even among persons with normal BMI. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.
Moon, Hyo-Bin; Park, Seung-Jae; Kim, Al-Chan; Jang, Jee-Hun
The purpose of this study was to identify the characteristics of muscular strength in upper limb and to present the preliminary information for development of sports injury prevention program and exercise rehabilitation program in wheelchair tennis players. Participants were 12 male wheelchair tennis players. Muscular strength was measured in shoulder and elbow joints with isokinetic dynamometer. Ipsilateral (IR) and bilateral (BR) balance ratio were calculated with isokinetic strength at 60°/sec. As a result, extension strength (ES) was significantly higher than flexion strength (FS) (Pelbow joint FS was significantly higher than ES (Pelbow joints and lower IR and BR in elbow joints could be the characteristics in male wheelchair tennis players. It is suggested that flexor strengthening program in nondominant shoulder joint, extensor strengthening program in both elbow joint, and flexor strengthening program in non-dominant elbow joint should be introduced for male wheelchair tennis players. PMID:24278887
This study examined the effectiveness of a brief theory-based intervention on muscular strength among adolescents in a physical education setting. The intervention adopted a process-based mental simulation technique. The self-reported frequency of practising for and actual levels of abdominal muscular strength/endurance as one component of…
Konovalčik, Šymon Vladyslav
Relationship Between Lower Limbs Proprioception and Muscular Strength Among Adolescents with Patellofemoral Pain Syndrome Physiotherapy Bachelor's Thesis The Author: Šymon Vladyslav Konovalčik Academic advisor: Lina Varnienė The aim of research work: The aim of this study was to evaluate the relationship between knee joint proprioception and knee extensor and flexor muscle strength, dinamic endurance and balance among adolescents with patellofemoral pain syndrome Tasks of work: 1. To assess t...
DiNucci, James M.; Pelton, Elois B.
This study was designed to construct a gross muscular strength test battery for girls 6-9 years of age in grades 1-3. The subjects for this investigation were a random sample of 183 girls in grades 1-3 of the public schools of Natchitoches, Louisiana. The variables selected were 22 cable tension strength tests developed by Clarke and associates.…
Kyriazis, Thomas A; Terzis, Gerasimos; Boudolos, Konstantinos; Georgiadis, Georgios
The aim of this study was to investigate changes in shot put performance, muscular power, and neuromuscular activation of the lower extremities, between the preseason and the competition period, in skilled shot put athletes using the rotational technique. Shot put performance was assessed at the start of the pre-season period as well as after 12 weeks, at the competition period, in nine shot putters. Electromyographic (EMG) activity of the right vastus lateralis muscle was recorded during all shot put trials. Maximum squat strength (1RM) and mechanical parameters during the countermovement jump (CMJ) on a force platform were also determined at pre-season and at competition period. Shot put performance increased 4.7% (p phase was increased significantly (p training period. Shot put performance was significantly related with muscular power and takeoff velocity during the CMJ, at competition period (r = 0.66, p competition period.
MÁRIO C. MARQUES
Full Text Available Problem Statement: During the last decades, strength and power training has been a major issue for, coaches,athletes and researchers. Unfortunately, despite the increasing professionalization of coaches and athletes, thereis little research data concerning performance in elite athletes. Several studies showed that a specific strengthtraining program can improve athletes’ maximal force and power production, reduce the incidence of injury, andcontribute to faster injury recovery times, thereby minimizing the number of missed practice sessions andcompetitions. To our best knowledge, however, there is no apparent consensus on the appropriate method ofstrength and muscular power training to enhance performance, especially in typically power sports. On this,some questions remain unresolved and there have focused objective of our study: How much strength does anathlete need? Is the maximum strength the key for success? Is the muscular power the main issue?Approach: Therefore, the aim of this study focuses on a literature scientific search extended about strength inpower sports specifically.Results: Studies in this area continue to contradict because they differ markedly in terms of design factors,including mode, frequency, intensity, frequency of training, and training history of subjects.Conclusions/Recommendations: We can conclude that once a given level of strength training intensity hasbeen reached in trained athletes, the appropriate physiological adaptations may well be optimized and thattraining beyond this limit provides no further benefits
the injury risks and inefficiencies of other methods for the more sophisticated assessment of human muscular strength and power. To provide...an environment of total safety. Limiting catches prevent injury through falling or loss of control of the loaded bar and a specially designed...J., Rodman, K.W., and Sebolt, D.R. The effect of endurance running on training adaptations in women participating in a weightlifting program. J
Moliner-Urdiales, Diego; Ortega, Francisco B; Vicente-Rodriguez, Germán; Rey-Lopez, Juan P; Gracia-Marco, Luis; Widhalm, Kurt; Sjöström, Michael; Moreno, Luis A; Castillo, Manuel J; Ruiz, Jonatan R
The objective of this study is to analyse the association of objectively assessed physical activity (PA) with muscular strength and fat-free mass in adolescents, and to determine whether meeting the current PA recommendations is associated with higher levels of muscular strength and fat-free mass. The present cross-sectional study comprised 363 Spanish adolescents (180 females) aged 12.5-17.5 years. PA was assessed by accelerometry and expressed as average PA (counts/min), and min/day of inactive, light, moderate, vigorous and moderate to vigorous PA (MVPA). MVPA was dichotomized into or = 60. Upper body muscular strength was measured with the handgrip strength test, and lower body muscular strength was measured with the standing broad jump, squat jump, counter movement jump and Abalakov tests. Fat-free mass was measured by DXA. We observed positive associations between vigorous PA and all the lower body muscular strength tests except for the counter movement jump in males. PA was not associated with fat-free mass in both males and females. Male adolescents engaged in at least 60 min/day MVPA performed better in the standing broad jump test. In conclusion, the findings of the present study suggest that only vigorous PA is associated with muscular strength, particularly lower-body muscular strength in male adolescents.
Milene F. Nunes
Full Text Available ABSTRACT Measuring muscle strength and motor function is part of Duchenne muscular dystrophy (DMD assessment. However, the relationship between these variables is controversial. Objective To investigate the relationship between muscle strength and motor function and between these variables and age. Method Muscle strength was measured by Medical Research Council (MRC scale and motor function, by Motor Function Measure (MFM, in 40 non-ambulatory patients. Spearman tests investigated the relationships between muscle strength, motor function and age. Results Total MRC and MFM scores were strongly related to each other (r = 0.94; p 0.05. Strong and moderate relationships between partial muscle strength and motor function scores were found. Higher correlation coefficients were found between total scores and Dimensions 2 (axial/ proximal control and 3 (distal control of MFM. Conclusion Muscle strength and motor function are strongly correlated and seem to decrease proportionally in DMD.
Full Text Available Aging is associated with sarcopenia, which is a loss of skeletal muscle mass and function. Coenzyme Q10 (CoQ10 is involved in several important functions that are related to bioenergetics and protection against oxidative damage; however, the role of CoQ10 as a determinant of muscular strength is not well documented. The aim of the present study was to evaluate the determinants of muscular strength by examining hand grip force in relation to CoQ10 status, gender, age and body mass index (BMI in two independent cohorts (n = 334, n = 967. Furthermore, peak flow as a function of respiratory muscle force was assessed. Spearman's correlation revealed a significant positive association between CoQ10/cholesterol level and hand grip in the basic study population (p<0.01 as well as in the validation population (p<0.001. In the latter, we also found a negative correlation with the CoQ10 redox state (p<0.01, which represents a lower percentage of the reduced form of CoQ10 (ubiquinol in subjects who exhibit a lower muscular strength. Furthermore, the age of the subjects showed a negative correlation with hand grip (p<0.001, whereas BMI was positively correlated with hand grip (p<0.01, although only in the normal weight subgroup (BMI <25 kg/m2. Analysis of the covariance (ANCOVA with hand grip as the dependent variable revealed CoQ10/cholesterol as a determinant of muscular strength and gender as the strongest effector of hand grip. In conclusion, our data suggest that both a low CoQ10/cholesterol level and a low percentage of the reduced form of CoQ10 could be an indicator of an increased risk of sarcopenia in humans due to their negative associations to upper body muscle strength, peak flow and muscle mass.
Śliwowski, Robert; Jadczak, Łukasz; Hejna, Rafał; Wieczorek, Andrzej
The purpose of this study was to investigate the effects of a resistance training program on the muscular strength of soccer players’ knees that initially presented unilateral and bilateral differences. For this study, a team of 24 male well-trained junior soccer players was divided into two strength program training groups: a Resistance Training Control Group (RTCG) composed of 10 players that did not have muscular imbalances and a Resistance Training Experimental Group (RTEG) composed of 14 players that had muscular imbalances. All players followed a resistance training program for six weeks, two times per week, during the transition period. The program of individualized strength training consisted of two parts. The first part, which was identical in terms of the choice of training loads, was intended for both training groups and contained two series of exercises including upper and lower body exercises. The second part of the program was intended only for RTEG and consisted of two additional series for the groups of muscles that had identified unilateral and bilateral differences. The applied program showed various directions in the isokinetic profile of changes. In the case of RTCG, the adaptations related mainly to the quadriceps muscle (the peak torque (PT) change for the dominant leg was statistically significant (p soccer players. PMID:26630271
Full Text Available The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9 and Power (n = 8 groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ, Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively. Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively, while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p < 0.05. Muscle fibre Cross Sectional Area (fCSA increased in all fibre types after Strength training by 19-26% (p < 0.05, while only type IIx fibres hypertrophied significantly after Power training. Type IIx fibres (% decreased after Strength but not after Power training. These results suggest that shot put throwing performance can be increased similarly after six weeks of either strength or ballistic power training in novice throwers, but with dissimilar muscular adaptations
Amirthalingam, Theban; Mavros, Yorgi; Wilson, Guy C; Clarke, Jillian L; Mitchell, Lachlan; Hackett, Daniel A
Amirthalingam, T, Mavros, Y, Wilson, GC, Clarke, JL, Mitchell, L, and Hackett, DA. Effects of a modified German volume training program on muscular hypertrophy and strength. J Strength Cond Res 31(11): 3109-3119, 2017-German Volume Training (GVT), or the 10 sets method, has been used for decades by weightlifters to increase muscle mass. To date, no study has directly examined the training adaptations after GVT. The purpose of this study was to investigate the effect of a modified GVT intervention on muscular hypertrophy and strength. Nineteen healthy men were randomly assign to 6 weeks of 10 or 5 sets of 10 repetitions for specific compound resistance exercises included in a split routine performed 3 times per week. Total and regional lean body mass, muscle thickness, and muscle strength were measured before and after the training program. Across groups, there were significant increases in lean body mass measures, however, greater increases in trunk (p = 0.043; effect size [ES] = -0.21) and arm (p = 0.083; ES = -0.25) lean body mass favored the 5-SET group. No significant increases were found for leg lean body mass or measures of muscle thickness across groups. Significant increases were found across groups for muscular strength, with greater increases in the 5-SET group for bench press (p = 0.014; ES = -0.43) and lat pull-down (p = 0.003; ES = -0.54). It seems that the modified GVT program is no more effective than performing 5 sets per exercise for increasing muscle hypertrophy and strength. To maximize hypertrophic training effects, it is recommended that 4-6 sets per exercise be performed, as it seems gains will plateau beyond this set range and may even regress due to overtraining.
Summary and Conclusion: Hatha yoga can improve anthropometric characteristics, muscular strength and flexibility among volunteers of different age group and can also be helpful in preventing and attenuating age related deterioration of these parameters.
Mazzini, L; Balzarini, C; Colombo, R; Mora, G; Pastore, I; De Ambrogio, R; Caligari, M
Creatine supplementation in humans has been reported to enhance power and strength both in normal subjects and in patients with various neuromuscular diseases. The purpose of this study was to examine the effects of supplementation on exercise performance and maximal voluntary isometric muscular contraction (MVIC) in Amyotrophic Lateral Sclerosis (ALS) patients. We report the results obtained in 28 patients with probable/definite ALS. In each patient we acquired the dynamometric measurement of MVIC in 10 muscle groups of upper and lower limbs and a measure of fatigue by means of an high-intensity intermittent protocol in elbow flexors and knee extensors muscles. All patients completed the protocols at the baseline and after supplementation of 20 g per day for 7 days and after supplementation of 3 g per day for 3 and 6 months. MVIC increased after 7 days of supplementation in 20 patients (70%) in knee extensors and in 15 (53%) of them also in elbow flexors. A statistically significant difference between pre and post-treatment mean values of MVIC was found both in elbow flexors (P<0.05) and knee extensors (p<0.04). The analysis of the slopes of fatigue test showed a statistically significant improvement after 7 days of supplementation in 11 patients (39%) in elbow flexors and in 9 patients (32%) also in knee extensors muscles. During the 6-month follow-up period all the examined parameters showed a linear progressive decline. In conclusion, our preliminary results have demonstrated that supplementation temporary increases maximal isometric power in ALS patients so it may be of potential benefit in situations such as high intensity activity and it can be proposed as a symptomatic treatment.
Chong, Kar Hau; Poh, Bee Koon
Full text: Despite significant advances in social and economic development, undernutrition remains a devastating public health problem that affects millions of children across the globe, particularly in developing nations. It is important to understand how changes in nutritional status affect physical health and function, so that undernutrition-related alterations can be identified and interpreted correctly. This paper aimed to determine the impact of undernutrition in children through the assessment of three nutrition-related indicators: body composition, muscular strength and bone status. This study is part of the Nutrition Survey of Malaysian Children, which is part of the four-country South East Asian Nutrition Surveys (SEANUTS). A total of 208 school children (102 boys, 106 girls) in the age range of 7 to 10 years were included in this analysis, of which 104 were underweight (WAZ<-2SD) and 104 were normal-weight group (-2SD≤WAZ≤+2SD), individually-matched for sex, age, and ethnicity. Anthropometric measurements included weight and height; and body composition was measured by bioelectrical impedance analysis. Muscular strength of both hands was assessed independently by hand-held dynamometer. Bone status was evaluated using a radial quantitative ultrasound system at one-third distal radius of the non-dominant hand. Anthropometric measurements and bone status were not significantly different between the sexes. Boys had significantly higher muscular strength and lean mass (p<0.05), but lower fat mass when compared to the girls (p<0.01). In both sexes, the undernourished group presented significantly lower anthropometric and body composition measurements and muscular strength than their normal-weight counterparts (p<0.001). However, no significant differences were observed for bone status between the two weight groups in boys (p = 0.09) and girls (p = 0.98). These findings imply that undernutrition can have profound negative impact on body composition as well
Willems, Sara M; Wright, Daniel J.; Day, Felix R
with involvement of psychomotor impairment (PEX14, LRPPRC and KANSL1). Mendelian randomization analyses are consistent with a causal effect of higher genetically predicted grip strength on lower fracture risk. In conclusion, our findings provide new biological insight into the mechanistic underpinnings of grip...... strength and the causal role of muscular strength in age-related morbidities and mortality....
Maamer Slimani, David Tod, Helmi Chaabene, Bianca Miarka, Karim Chamari
Full Text Available The aims of the present review were to (i provide a critical overview of the current literature on the effects of mental imagery on muscular strength in healthy participants and patients with immobilization of the upper extremity (i.e., hand and anterior cruciate ligament (ACL, (ii identify potential moderators and mediators of the “mental imagery-strength performance” relationship and (iii determine the relative contribution of electromyography (EMG and brain activities, neural and physiological adaptations in the mental imagery-strength performance relationship. This paper also discusses the theoretical and practical implications of the contemporary literature and suggests possible directions for future research. Overall, the results reveal that the combination of mental imagery and physical practice is more efficient than, or at least comparable to, physical execution with respect to strength performance. Imagery prevention intervention was also effective in reducing of strength loss after short-term muscle immobilization and ACL. The present review also indicates advantageous effects of internal imagery (range from 2.6 to 136.3% for strength performance compared with external imagery (range from 4.8 to 23.2%. Typically, mental imagery with muscular activity was higher in active than passive muscles, and imagining “lifting a heavy object” resulted in more EMG activity compared with imagining “lifting a lighter object”. Thus, in samples of students, novices, or youth male and female athletes, internal mental imagery has a greater effect on muscle strength than external mental imagery does. Imagery ability, motivation, and self-efficacy have been shown to be the variables mediating the effect of mental imagery on strength performance. Finally, the greater effects of internal imagery than those of external imagery could be explained in terms of neural adaptations, stronger brain activation, higher muscle excitation, greater somatic
Tatiana M. Pizzato
Full Text Available BACKGROUND: Grip strength is used to infer functional status in several pathological conditions, and the hand dynamometer has been used to estimate performance in other areas. However, this relationship is controversial in neuromuscular diseases and studies with the bulb dynamometer comparing healthy children and children with Duchenne Muscular Dystrophy (DMD are limited. OBJECTIVE: The evolution of grip strength and the magnitude of weakness were examined in boys with DMD compared to healthy boys. The functional data of the DMD boys were correlated with grip strength. METHOD: Grip strength was recorded in 18 ambulant boys with DMD (Duchenne Group, DG aged 4 to 13 years (mean 7.4±2.1 and 150 healthy volunteers (Control Group, CG age-matched using a bulb dynamometer (North Coast- NC70154. The follow-up of the DG was 6 to 33 months (3-12 sessions, and functional performance was verified using the Vignos scale. RESULTS: There was no difference between grip strength obtained by the dominant and non-dominant side for both groups. Grip strength increased in the CG with chronological age while the DG remained stable or decreased. The comparison between groups showed significant difference in grip strength, with CG values higher than DG values (confidence interval of 95%. In summary, there was an increment in the differences between the groups with increasing age. Participants with 24 months or more of follow-up showed a progression of weakness as well as maintained Vignos scores. CONCLUSIONS: The amplitude of weakness increased with age in the DG. The bulb dynamometer detected the progression of muscular weakness. Functional performance remained virtually unchanged in spite of the increase in weakness.
Full Text Available Exercise training induces muscular adaptations that are highly specific to the type of exercise. For a systematic study of the differentiated exercise adaptations on a molecular level mouse models have been used successfully. The aim of the current study was to develop a suitable mouse model of isometric strength exercise training characterized by specific adaptations known from strength training. C57BL/6 mice performed an isometric strength training (ST for 10 weeks 5 days/week. Additionally, either a sedentary control group (CT or a regular endurance training group (ET groups were used as controls. Performance capacity was determined by maximum holding time (MHT and treadmill spirometry, respectively. Furthermore, muscle fiber types and diameter, muscular concentration of phosphofructokinase 1 (PFK, succinate dehydrogenase (SDHa, and glucose transporter type 4 (GLUT4 were determined. In a further approach, the effect of ST on glucose intolerance was tested in diabetic mice. In mice of the ST group we observed an increase of MHT in isometric strength tests, a type II fiber hypertrophy, and an increased GLUT4 protein content in the membrane fraction. In contrast, in mice of the ET group an increase of VO(2max, a shift to oxidative muscle fiber type and an increase of oxidative enzyme content was measured. Furthermore strength training was effective in reducing glucose intolerance in mice fed a high fat diet. An effective murine strength training model was developed and evaluated, which revealed marked differences in adaptations known from endurance training. This approach seems also suitable to test for therapeutical effects of strength training.
Kim, Dong Ki; Lee, Jeong Tae
This paper presents a force measurement system that can measure a lower-body muscular strength of skaters. The precise measurement and analysis of the left and right lower-body strength of skaters is necessary, because a left/right lower-body strength balance is helpful to improve the athletes' performance and to protect them from injury. The system is constructed with a skate sliding board, a couple of sensor-units with load cell, indicator and control box, guard, force pad, and support bracket. The developed force measurement system is calibrated by the calibration setup, and the uncertainty of the force sensing unit on the left is within 0.087% and the uncertainty of the force sensing unit on the right is within 0.109%. In order to check the feasibility of the developed measurement device, a kinematic analysis is conducted with skater. As a result, the subject shows the deviation of left and right of 12.1 N with respect to average strength and 39.1 N with respect to the maximum strength. This evaluation results are reliable enough to make it possible to measure a lower-body muscular strength of skaters. The use of this measurement system will be expected to correct the posture of skaters and record the sports dynamics data for each athlete. It is believed that through the development of this equipment, skaters in elementary, middle, high schools, colleges, and the professional level have the systematic training to compete with world-class skaters.
Full Text Available Zhixiong Zhou,1,2 Lu Zheng,3 Dengyun Wei,4 Ming Ye,3 Xun Li2 1School of Physical Education and Coaching Science, Capital University of Physical Education and Sports, Beijing, People’s Republic of China; 2Graduate School, Beijing Sport University, Beijing, People’s Republic of China; 3School of Kinesiology and Health Education, Capital University of Physical Education and Sports, Beijing, People’s Republic of China; 4Department of Physical Education, Anhui Normal University, Anhui, People’s Republic of China Background: The literature is inconsistent and inconclusive on the relationship between bone mineral density (BMD and muscular strength in postmenopausal women. Objective: To evaluate the relationship between isokinetically and isometrically determined muscle strength and BMD in postmenopausal women of different age groups. Methods: Healthy postmenopausal women (n = 293; mean age, 54.22 ± 3.85 years were enrolled in this study. They were grouped by age according to World Health Organization life expectancy: 45–50 years, 51–53 years, 54–56 years, 57–59 years, and 60–64 years. Total BMD, L2–4 BMD, and femoral neck BMD were measured by dual-energy X-ray bone densitometry; isokinetic and isometric muscle strength of the right hip and trunk muscles were measured during contractile exercise. Stepwise regression analysis was used to examine the relationships between BMD and strength measures, controlling for subject age and years since menopause. Results: Results of stepwise regression showed that hip extensor and flexor strength at 120°/second and back extend strength at 30°/second accounted for 26% total BMD variance among menopausal subjects, 19% L2–4 BMD variance, and 15% femoral neck BMD variance; in postmenopausal women of different age groups, hip extensor and flexor strength at 120°/second and back extend strength at 30°/second accounted for 25%–35% total BMD variance. Conclusion: Different optimal strength
Willems, Sara M.; Wright, D.J.; Day, Felix R.; Trajanoska, Katerina; Joshi, P.K.; Morris, John A.; Matteini, Amy M.; Garton, Fleur C.; Grarup, Niels; Oskolkov, Nikolay; Thalamuthu, Anbupalam; Mangino, Massimo; Liu, Jun; Demirkan, Ayse; Lek, Monkol; Xu, Liwen; Wang, Guan; Oldmeadow, Christopher; Gaulton, Kyle J.; Lotta, Luca A.; Miyamoto-Mikami, Eri; Rivas, Manuel A.; White, Tom; Loh, Po Ru; Aadahl, Mette; Amin, Najaf; Attia, John R.; Austin, Krista; Benyamin, Beben; Brage, Søren; Cheng, Yu Ching; Ciȩszczyk, Paweł; Derave, Wim; Eriksson, Karl Fredrik; Eynon, Nir; Linneberg, Allan; Lucia, Alejandro; Massidda, Myosotis; Mitchell, Braxton D.; Miyachi, Motohiko; Murakami, Haruka; Padmanabhan, Sandosh; Pandey, Ashutosh; Papadimitriou, Ioannis; Rajpal, Deepak K.; Sale, Craig; Schnurr, Theresia M.; Sessa, Francesco; Shrine, Nick; Tobin, Martin D.; Varley, Ian; Wain, Louise V.; Wray, Naomi R.; Lindgren, Cecilia M.; MacArthur, Daniel G.; Waterworth, Dawn M.; McCarthy, Mark I.; Pedersen, Oluf; Khaw, Kay Tee; Kiel, Douglas P.; Pitsiladis, Yannis; Fuku, Noriyuki; Franks, Paul W.; North, Kathryn N.; Duijn, Van C.M.; Mather, Karen A.; Hansen, Torben; Hansson, Ola; Spector, Tim D.; Murabito, Joanne M.; Richards, J.B.; Rivadeneira, Fernando; Langenberg, Claudia; Perry, John R.B.; Wareham, Nick J.; Scott, Robert A.; Oei, Ling; Zheng, Hou Feng; Forgetta, Vincenzo; Leong, Aaron; Ahmad, Omar S.; Laurin, Charles; Mokry, Lauren E.; Ross, Stephanie; Elks, Cathy E.; Bowden, Jack; Warrington, Nicole M.; Murray, Anna; Ruth, Katherine S.; Tsilidis, Konstantinos K.; Medina-Gómez, Carolina; Estrada, Karol; Bis, Joshua C.; Chasman, Daniel I.; Demissie, Serkalem; Enneman, Anke W.; Hsu, Yi Hsiang; Ingvarsson, Thorvaldur; Kähönen, Mika; Kammerer, Candace; Lacroix, Andrea Z.; Li, Guo; Liu, Ching Ti; Liu, Yongmei; Lorentzon, Mattias; Mägi, Reedik; Mihailov, Evelin; Milani, Lili; Moayyeri, Alireza; Nielson, Carrie M.; Sham, Pack Chung; Siggeirsdotir, Kristin; Sigurdsson, Gunnar; Stefansson, Kari; Trompet, Stella; Thorleifsson, Gudmar; Vandenput, Liesbeth; Velde, Van Der Nathalie; Viikari, Jorma; Xiao, Su Mei; Zhao, Jing Hua; Evans, Daniel S.; Cummings, Steven R.; Cauley, Jane; Duncan, Emma L.; Groot, De Lisette C.P.G.M.; Esko, Tonu; Gudnason, Vilmundar; Harris, Tamara B.; Jackson, Rebecca D.; Jukema, J.W.; Ikram, Arfan M.A.; Karasik, David; Kaptoge, Stephen; Kung, Annie Wai Chee; Lehtimäki, Terho; Lyytikäinen, Leo Pekka; Lips, Paul; Luben, Robert; Metspalu, Andres; Meurs, van Joyce B.; Minster, Ryan L.; Orwoll, Erick; Oei, Edwin; Psaty, Bruce M.; Raitakari, Olli T.; Ralston, Stuart W.; Ridker, Paul M.; Robbins, John A.; Smith, Albert V.; Styrkarsdottir, Unnur; Tranah, Gregory J.; Thorstensdottir, Unnur; Uitterlinden, Andre G.; Zmuda, Joseph; Zillikens, M.C.; Ntzani, Evangelia E.; Evangelou, Evangelos; Ioannidis, John P.A.; Evans, David M.; Ohlsson, Claes
Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of
Willems, Sara M.; Wright, Daniel J.; Day, Felix R.
Hand grip strength is a widely used proxy of muscular fitness, a marker of frailty, and predictor of a range of morbidities and all-cause mortality. To investigate the genetic determinants of variation in grip strength, we perform a large-scale genetic discovery analysis in a combined sample of 1...
Slimani, Maamer; Tod, David; Chaabene, Helmi; Miarka, Bianca; Chamari, Karim
The aims of the present review were to (i) provide a critical overview of the current literature on the effects of mental imagery on muscular strength in healthy participants and patients with immobilization of the upper extremity (i.e., hand) and anterior cruciate ligament (ACL), (ii) identify potential moderators and mediators of the “mental imagery-strength performance” relationship and (iii) determine the relative contribution of electromyography (EMG) and brain activities, neural and physiological adaptations in the mental imagery-strength performance relationship. This paper also discusses the theoretical and practical implications of the contemporary literature and suggests possible directions for future research. Overall, the results reveal that the combination of mental imagery and physical practice is more efficient than, or at least comparable to, physical execution with respect to strength performance. Imagery prevention intervention was also effective in reducing of strength loss after short-term muscle immobilization and ACL. The present review also indicates advantageous effects of internal imagery (range from 2.6 to 136.3%) for strength performance compared with external imagery (range from 4.8 to 23.2%). Typically, mental imagery with muscular activity was higher in active than passive muscles, and imagining “lifting a heavy object” resulted in more EMG activity compared with imagining “lifting a lighter object”. Thus, in samples of students, novices, or youth male and female athletes, internal mental imagery has a greater effect on muscle strength than external mental imagery does. Imagery ability, motivation, and self-efficacy have been shown to be the variables mediating the effect of mental imagery on strength performance. Finally, the greater effects of internal imagery than those of external imagery could be explained in terms of neural adaptations, stronger brain activation, higher muscle excitation, greater somatic and
García-Flores, Fabián Ituriel; Rivera-Cisneros, Antonio Eugenio; Sánchez-González, Jorge Manuel; Guardado-Mendoza, Rodolfo; Torres-Gutiérrez, Jorge Luis
Evidence of the benefit on propioceptive neuromuscular facilitation for reducing falls in older people does not exist. The aim of this study is to evaluate the effects of propioceptive facilitation over falls and biomechanical variables, in comparison to standard treatment and control groups. Series cases comparative for the 24 participants were recruited and randomnly assigned to 3 groups. Group 1, propioceptive neuromuscular facilitation, group 2, standard treatment, and 3 control. Falls and biomechanic variables were measured before and after. Chi(2) was used for falls and multiple regression for biomechanical variables, Participants had similar falls in previous year. Women had higher falls in a relation 7:1 women-men. After intervention, there was no difference between 3 groups. A correlation exista between muscular strength and gait speed with one foot position time r(2) = 0.67, p = 0.02. Improving 1kilogram-force of muscular strength of pelvic limb and 0.1meter/second in gait speed, balance (unipodal position time) increases balance by 11.3%. After 3 months of intervention group 2 got 7.9kg-force and 0.26m/s of profit, while group 1 had 4.1kg-force and 0.15m/s and control group 2.4kg-force and 0.1m/s. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.
Full Text Available The purpose of the present study was to evaluate the acute effect of caffeine on the muscular strength performance in addition to the possible hemodynamic changes during a strength training session. Thirteen strength training experienced male subjects were submitted to a protocol of three sets of 10RM for bench press (BP, pull press (PP, leg extension (LE and leg curl (LC, according to three conditions: no supplementation (C; 250 mg of caffeine supplementation (S; placebo (P. All subjects were submitted to an anthropometric evaluation, followed by a 10RM familiarization test. Hemodynamic measurements – heart rate (HR and blood pressure (BP – were carried out before, during and after each session. Holding 48 hours time intervals, participants were submitted to three randomly presented 10RM tests according to C, S and P conditions. For conditions S and C, significant differences were found in BP and LE. No significant differences in HR and BP were found. Results seem to suggest an ergogenic effect of caffeine on submaximal muscle strength during a session of strength training.
Zaras, Nikolaos; Spengos, Konstantinos; Methenitis, Spyridon; Papadopoulos, Constantinos; Karampatsos, Giorgos; Georgiadis, Giorgos; Stasinaki, Aggeliki; Manta, Panagiota; Terzis, Gerasimos
The purpose of the present study was to investigate the effects of 6 weeks strength vs. ballistic-power (Power) training on shot put throwing performance in novice throwers. Seventeen novice male shot-put throwers were divided into Strength (N = 9) and Power (n = 8) groups. The following measurements were performed before and after the training period: shot put throws, jumping performance (CMJ), Wingate anaerobic performance, 1RM strength, ballistic throws and evaluation of architectural and morphological characteristics of vastus lateralis. Throwing performance increased significantly but similarly after Strength and Power training (7.0-13.5% vs. 6.0-11.5%, respectively). Muscular strength in leg press increased more after Strength than after Power training (43% vs. 21%, respectively), while Power training induced an 8.5% increase in CMJ performance and 9.0 - 25.8% in ballistic throws. Peak power during the Wingate test increased similarly after Strength and Power training. Muscle thickness increased only after Strength training (10%, p ballistic power training in novice throwers, but with dissimilar muscular adaptations. Key pointsBallistic-power training with 30% of 1RM is equally effective in increasing shot put performance as strength training, in novice throwers, during a short training cycle of six weeks.In novice shot putters with relatively low initial muscle strength/mass, short-term strength training might be more important since it can increase both muscle strength and shot put performance.The ballistic type of power training resulted in a significant increase of the mass of type IIx muscle fibres and no change in their proportion. Thus, this type of training might be used effectively during the last weeks before competition, when the strength training load is usually reduced, in order to increase muscle power and shot put performance in novice shot putters.
Myers, Natalie L; Toonstra, Jenny L; Smith, Jacob S; Padgett, Cooper A; Uhl, Tim L
The Advanced Throwers Ten Exercise Program incorporates sustained isometric contractions in conjunction with dynamic shoulder movements. It has been suggested that incorporating isometric holds may facilitate greater increases in muscular strength and endurance. However, no objective evidence currently exists to support this claim. The purpose of this research was to compare the effects of a sustained muscle contraction resistive training program (Advanced Throwers Ten Program) to a more traditional exercise training protocol to determine if increases in shoulder muscular strength and endurance occur in an otherwise healthy population. It was hypothesized that utilizing a sustained isometric hold during a shoulder scaption exercise from the Advanced Throwers Ten would produce greater increases in shoulder strength and endurance as compared to a traditional training program incorporating a isotonic scapular plane abduction (scaption) exercise. Randomized Clinical Trial. Fifty healthy participants were enrolled in this study, of which 25 were randomized into the traditional training group (age: 26 ± 8, height:172 ± 10 cm, weight: 73 ± 13 kg, Marx Activity Scale: 11 ± 4) and 25 were randomized to the Advanced Throwers Ten group (age: 28 ± 9, height: 169 ± 23 cm, weight: 74 ± 16 kg, Marx Activity Scale: 11 ± 5). No pre-intervention differences existed between the groups (P>0.05). Arm endurance and strength data were collected pre and post intervention using a portable load cell (BTE Evaluator, Hanover, MD). Both within and between group analyses were done in order to investigate average torque (strength) and angular impulse (endurance) changes. The traditional and Advanced Throwers Ten groups both significantly improved torque and angular impulse on both the dominant and non-dominant arms by 10-14%. There were no differences in strength or endurance following the interventions between the two training groups (p>0
Ryan D. Burns
Full Text Available The predictive relationship between muscular strength and endurance and cardio-metabolic health, independent from aerobic fitness, is not clear in disadvantaged Hispanic children. The purpose of this study was to examine the predictive relationship between muscular strength and endurance and clustered cardio-metabolic risk, controlling for aerobic fitness, in Hispanic children from low-income schools. Participants were 320 Hispanic children (Mean age = 10.1 ± 1.1 years; 164 girls, 156 boys recruited during the 2014–2015 and 2015–2016 academic years from five low-income schools from the state of Utah in the U.S. Muscular strength and endurance was assessed using the push-up and curl-up tests and estimated VO2 Peak was calculated from the Progressive Aerobic Cardiovascular Endurance Run. A clustered metabolic syndrome composite score (MetS was calculated from cardio-metabolic health measurements consisting of HDL cholesterol, triglycerides, waist circumference, blood glucose, and mean arterial pressure (MAP. Multi-level general linear mixed effects models were used to examine the predictive relationship between muscular strength and endurance and MetS, controlling for the effect of aerobic fitness and the clustering of children within classrooms and schools. Children who were in the middle and upper tertiles for muscular strength and endurance associated with a lower (more favorable MetS score (middle tertile: β = −2.59, 95% C.I. [−4.23, −0.95], p < 0.05; upper tertile: β = −1.57, 95% C.I. [−3.20, −0.16], p < 0.05. The results suggest that higher levels of muscular strength and endurance relate to lower cardio-metabolic risk, independent of aerobic fitness, in Hispanic children from low-income schools.
Tim J Gabbett
Full Text Available This study investigated the influence of repeated high-intensity effort exercise on tackling ability in rugby league players, and determined the relationship between physical qualities and tackling ability under fatigued conditions in these athletes. Eleven semi-professional rugby league players underwent measurements of speed (10 m and 40 m sprint, upper-body strength (4 repetition maximum [RM] bench press and weighted chin-up, upper-body muscular endurance (body mass maximum repetition chin-up, body mass maximum repetition dips, lower-body strength (4RM squat, and estimated maximal aerobic power (multi-stage fitness test. Tackling ability was assessed using a standardized one-on-one tackling test, before, during, and following four bouts of repeated high-intensity effort (RHIE exercise. The relationship between physical qualities and fatigue-induced decrements in tackling ability were determined using Pearson product moment correlation coefficients. Each cycle of the RHIE protocol induced progressive reductions in tackling ability. A moderate reduction (Effect Size = ~-1.17 ± 0.60, -34.1 ± 24.3% in tackling ability occurred after the fourth cycle of the RHIE protocol. Players with greater relative lower-body strength (i.e. 4RM squat/kg had the best tackling ability under fatigued conditions (r = 0.72, p = 0.013. There were no significant relationships between tackling ability under fatigued conditions and any other physical quality. These findings suggest that lower-body strength protects against fatigue-induced decrements in tackling ability. The development of lower-body strength should be a priority to facilitate the development of robust tackling skills that are maintained under fatigue.
Lamb, David R.
The efficacy of steroids in development of muscular strength in athletes is not proven. Their long-term use is increasingly being associated with liver disorders, including liver cancer, and other health problems. (JD)
Full Text Available Background & objectives: Enhanced muscle strength is seen when resistance exercise is combined with the consumption of nutritional supplements. Although there is a limited number of studies available about the efficacy of gamma oryzanol supplementation with resistance exercise in humans, but its usage as a nutritional supplement for strength is common in athletes. The aim of this study was to determine the effects of gamma oryzanol supplementation during 9-week resistance training on muscular strength and anthropometric measurements of young healthy males. Methods: In this double-blind clinical trial, changes of anthropometric measurements and muscular strength were studied after chronic resistance exercise and gamma oryzanol supplementation in 30 healthy volunteers (16 in supplement and 14 in placebo. Each day, gamma oryzanol supplement (600 mg and placebo (the same amount of lactose were consumed after training. The participants exercised with 80 per cent 1-Repetition Maximum (1-RM, for one hour and four days/week. Anthropometric measurements and subjects′ 1-RM for muscular strength were determined at the commencement and end of the 9-week study. Results: There was no significant difference between the baseline characteristics and target variables at baseline between the two groups. After gamma oryzanol supplementation, there was no significant difference in the means of anthropometric and skin fold measurements between the supplement and placebo groups. However, there were significant differences between the supplement and placebo groups for 1-RM of bench press and leg curl, which showed that gamma oryzanol improved muscle strength following resistance training. Interpretation & conclusions: Our findings indicated that 600 mg/day gamma oryzanol supplementation during the 9-week resistance training did not change anthropometric and body measurements, but it increased muscular strength in young healthy males. Further, studies need to be done
Wokke, B H; van den Bergen, J C; Versluis, M J; Niks, E H; Milles, J; Webb, A G; van Zwet, E W; Aartsma-Rus, A; Verschuuren, J J; Kan, H E
The purpose of this study was to assess leg muscle quality and give a detailed description of leg muscle involvement in a series of Duchenne muscular dystrophy patients using quantitative MRI and strength measurements. Fatty infiltration, as well as total and contractile (not fatty infiltrated) cross sectional areas of various leg muscles were determined in 16 Duchenne patients and 11 controls (aged 8-15). To determine specific muscle strength, four leg muscle groups (quadriceps femoris, hamstrings, anterior tibialis and triceps surae) were measured and related to the amount of contractile tissue. In patients, the quadriceps femoris showed decreased total and contractile cross sectional area, attributable to muscle atrophy. The total, but not the contractile, cross sectional area of the triceps surae was increased in patients, corresponding to hypertrophy. Specific strength decreased in all four muscle groups of Duchenne patients, indicating reduced muscle quality. This suggests that muscle hypertrophy and fatty infiltration are two distinct pathological processes, differing between muscle groups. Additionally, the quality of remaining muscle fibers is severely reduced in the legs of Duchenne patients. The combination of quantitative MRI and quantitative muscle testing could be a valuable outcome parameter in longitudinal studies and in the follow-up of therapeutic effects. Copyright © 2014 Elsevier B.V. All rights reserved.
Hobayan, Kalani; Patterson, Debra; Sherman, Clay; Wiersma, Lenny
In a society in which obesity levels have tripled in the past 30 years, the importance of increased fitness levels within the academic setting has become even more critical. The purpose of this study was to investigate the validity of alternative Fitnessgram upper body tests of muscular strength and endurance among seventh and eighth grade males…
Conclusion: These results suggested that the manual dexterity in the hand function was attenuated with increasing age. We considered that this attenuating effect was associated with a decline in tactile sensibility rather than a change in the muscular strength of the hand.
Manocchia, Pasquale; Spierer, David K; Lufkin, Adrienne K S; Minichiello, Jacqueline; Castro, Jessica
Kettlebells are a popular implement in many strength and conditioning programs, and their benefits are touted in popular literature, books, and videos. However, clinical data on their efficacy are limited. The purpose of this study was to examine whether kettlebell training transfers strength and power to weightlifting and powerlifting exercises and improves muscular endurance. Thirty-seven subjects were assigned to an experimental (EXP, n = 23; mean age = 40.9 ± 12.9 years) or a control group (CON; n = 14; mean age = 39.6 ± 15.8 years), range 18-72 years. The participants were required to perform assessments including a barbell clean and jerk, barbell bench press, maximal vertical jump, and 45° back extensions to volitional fatigue before and after a 10-week kettlebell training program. Training was structured in a group setting for 2 d·wk(-1) for 10 weeks. A repeated measures analysis of variance was conducted to determine group × time interactions and main effects. Post hoc pairwise comparisons were conducted when appropriate. Bench press revealed a time × group interaction and a main effect (p power and strength in response to 10 weeks of training with kettlebells. Traditional training methods may not be convenient or accessible for strength and conditioning specialists, athletes, coaches, and recreational exercisers. The current data suggest that kettlebells may be an effective alternative tool to improve performance in weightlifting and powerlifting.
Full Text Available Background: Lack of mobility and motor impairments can intensify mental health problems in the elderly. Muscle weakness is one of the most important cause of fall in the old individuals. Muscular performance is regarded as one of the significant components of quality of life in older adults. Aim: This study aimed to investigate the effect of resistance training using Thera-Band on muscular strength and quality of life among the elderly. Method: This randomized clinical trial was conducted on 70 elderly people referring to the health centers of Mashhad in 2016. The participants were randomly assigned into two groups of intervention and control. The intervention group was subjected to lower- and upper-extremity resistance training with Thera-Band performed two thirty-minute sessions a week for six weeks. However, the control group did not receive any training. Data collection was performed using a dynamometer and the short version of the World Health Organization Quality of Life. The data were analyzed in SPSS version 16 using independent t-test, Mann-Whitney U test, paired t-test, Chi-square test, and exact Chi-square. Results: The mean ages of the individuals in the intervention and control groups were 69.7±6.1 and 77.2±6.2 years, respectively. After intervention, the mean scores of quality of life (P>0.001 and muscular strength in the upper and lower extremities (P>0.001 were significantly higher in the intervention group than those in the control group. Implications for Practice: Resistance training with Thera-Band could enhance muscular strength and improve quality of life in the elderly. It was concluded that the promotion of this exercise program could have a positive effect on the muscular strength and quality of life among this population.
Lindell K. Weaver
Full Text Available The primary purpose of this study was to identify if serum 25-hydroxyvitamin D (25(OHD concentrations predict muscular weakness after intense exercise. We hypothesized that pre-exercise serum 25(OHD concentrations inversely predict exercise-induced muscular weakness. Fourteen recreationally active adults participated in this study. Each subject had one leg randomly assigned as a control. The other leg performed an intense exercise protocol. Single-leg peak isometric force and blood 25(OHD, aspartate and alanine aminotransferases, albumin, interferon (IFN-γ, and interleukin-4 were measured prior to and following intense exercise. Following exercise, serum 25(OHD concentrations increased (p < 0.05 immediately, but within minutes, subsequently decreased (p < 0.05. Circulating albumin increases predicted (p < 0.005 serum 25(OHD increases, while IFN-γ increases predicted (p < 0.001 serum 25(OHD decreases. Muscular weakness persisted within the exercise leg (p < 0.05 and compared to the control leg (p < 0.05 after the exercise protocol. Serum 25(OHD concentrations inversely predicted (p < 0.05 muscular weakness (i.e., control leg vs. exercise leg peak isometric force immediately and days (i.e., 48-h and 72-h after exercise, suggesting the attenuation of exercise-induced muscular weakness with increasing serum 25(OHD prior to exercise. Based on these data, we conclude that pre-exercise serum 25(OHD concentrations could influence the recovery of skeletal muscle strength after an acute bout of intense exercise.
Vorup Petersen, Jacob; Tybirk, Jonas; Gunnarsson, Thomas Petursson
PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were rand...... and speed endurance training, along with a reduced training volume, can improve short-term exercise capacity and induce muscular adaptations related to anaerobic capacity in endurance-trained runners.......PURPOSE: To investigate the effects of combined strength and speed endurance (SE) training along with a reduced training volume on performance, running economy and muscular adaptations in endurance-trained runners. METHODS: Sixteen male endurance runners (VO2-max: ~60 ml kg(-1) min(-1)) were...... randomly assigned to either a combined strength and SE training (CSS; n = 9) or a control (CON; n = 7) group. For 8 weeks, CSS replaced their normal moderate-intensity training (~63 km week(-1)) with SE (2 × week(-1)) and strength training (2 × week(-1)) as well as aerobic high (1 × week(-1)) and moderate...
Hale, Bruce D; Roth, Andrew D; DeLong, Ryan E; Briggs, Michael S
Researchers have hypothesized differences in exercise dependence and drive for muscularity between bodybuilders and power lifters, while others have not found the predicted differences. This study assessed 146 weight lifters (bodybuilders, n=59; power lifters, n=47; fitness lifters, n=40) on the Exercise Dependence Scale, Bodybuilding Dependence Scale, and the Drive for Muscularity Scale. Results showed that bodybuilders and power lifters were significantly higher than fitness lifters on EDS Total, 7 EDS scales, and the 3 BDS scales. In contrast, power lifters were found to be significantly higher on DMS Total and DMS Behavior scales than bodybuilders. The regression results suggest that exercise dependence may be directly related to the drive for muscularity. 2010 Elsevier Ltd. All rights reserved.
Matheus Amarante do Nascimento
Full Text Available The aim of this study was to compare motor performance in modified pull-up (MPUand flexed knee push-up (FKPU tests in young women. Thirty-five apparently healthy women (20.1±2.2 years were submitted to each one of the tests at an interval of48 hours in a random balanced design. Most individuals performed between 0 an d 10 repetitions (86% of the MPU test, and approximately 17% did not perform even one repetitions. On the other hand, the highest prevalence of outcomes for the FKPUtest was between 16 and 35 repetitions (71%. The Wilcoxon test identified statistically significant differences (p MPU. A moderate agreement (kappa =0.40 was found between the performance in both tests. Negative correlations of low magnitude (r=-0.23 to 0.46 were found between morphological variables (body weight,height, fat mass, and lean body mass and motor performance in both tests. The results suggest that the FKPU test is presented as a better indicator ofmuscular endurance levels, where as the MPU test seems to better discriminate muscular strength in young women.
Full Text Available In the studies of human neuromuscular function, the function of leg muscles has been most often measured, particularly the function of the knee extensors. Therefore, this review will be focused on knee extensors, methods for assessment of its function, the interdependence of strength and power, relations that describe these two abilities and the influence of various factors on their production (resistance training, stretching, movement tasks, age, etc.. Given that it consists of four separate muscles, the variability of their anatomical characteristics affects their participation in strength and power production, depending on the type of movement and motion that is performed. Since KE is active in a variety of activities it must be able to generate great strength in a large and diverse range of muscle lengths and high shortening velocities, in respect to different patterns of strength production, and thus different generation capacities within the muscle (Blazevich et al., 2006. It has been speculated that KE exerts its Pmax at workloads close to subject's own body weight or lower (Rahmani et al., 2001, which is very close to the maximum dynamic output hypothesis (MDI of Jaric and Markovic (2009. Changes under the influence of resistance training or biological age are variously manifested in muscle's morphological, physiological and neural characteristics, and thus in strength and power. Understanding the issues related to strength and power as abilities of great importance for daily activities, is also important for sports and rehabilitation. Performances improvement in sports in which leg muscles strength and power are crucial, as well as recovery after the injuries, are largely dependent on the research results regarding KE function. Also, the appropriate strength balance between knee flexors and extensors is important for the knee joint stability, so that the presence of imbalance between these two muscle groups might be a risk factor for
Over the last decade research involving nutritional supplementation and sport performance has increased substantially. Strength and power athletes have specific needs to optimize their performance. Nutritional supplementation cannot be viewed as a replacement for a balanced diet but as an important addition to it. However, diet and supplementation are not mutually exclusive, nor does one depend on the other. Strength and power athletes have four general areas of supplementation needs. First, strength athletes need supplements that have a direct effect on performance. The second group of supplements includes those that promote recovery. The third group comprises the supplements that enhance immune function. The last group of supplements includes those that provide energy or have a direct effect on the workout. This chapter reviews the key supplements needed to optimize the performance and training of the strength athlete.
Quantification of muscle strength and motor ability in patients with Duchenne muscular dystrophy on steroid therapy Quantificação da força muscular e habilidades motoras em pacientes com distrofia muscular de Duchenne em corticoterapia
Samara Lamounier Santana Parreira
Full Text Available OBJECTIVE: An assessment protocol was applied to quantify and describe muscular strength and motor abilities of 32 patients with Duchenne muscular dystrophy (DMD, aged between 5 and 12 years on steroid therapy. METHOD: Assessments were made monthly for the first six months and with intervals of two months thereafter until the 14-month end point. The tests employed included: the Medical Research Council (MRC scale; the Hammersmith motor ability score; maximum weight lift; timed rise from floor and nine-meter walk. RESULTS: The results showed that loss of muscular strength and motor abilities were slowed in comparison to that observed in the natural evolution of the disease according to the literature. CONCLUSION: We conclude that a swift and objective assessment may be performed using the MRC scale for lower limbs and trunk, the Hammersmith motor ability score, timed nine-meter walk and weight lifts.OBJETIVO: Um protocolo de avaliação foi aplicado com o objetivo de quantificar e descrever evolutivamente a força muscular e as habilidades motoras de 32 pacientes com distrofia muscular de Duchenne (DMD, com idades variando de 5 a 12 anos, em corticoterapia. MÉTODO: As avaliações foram aplicadas mensalmente durante os primeiros seis meses e bimensais até completar um período de 14 meses. Os testes empregados foram: escala da "Medical Research Council" (MRC; Hammersmith "motor ability score"; levantamento da carga máxima de peso; cronometragem do tempo para levantar-se do chão e percorrer nove metros. RESULTADOS: Os resultados demonstraram que a perda da força muscular e das habilidades motoras foi mais lenta do que a observada na evolução natural da doença, como descrito na literatura internacional. CONCLUSÃO: Concluímos que uma rápida e objetiva avaliação pode ser executada utilizando a escala MRC para membros inferiores e tronco, Hammersmith motor ability score, cronometragem do tempo para percorrer 9 metros.e o levantamento de
Lima, Camila D; Brown, Lee E; Wong, Megan A; Leyva, Whitney D; Pinto, Ronei S; Cadore, Eduardo L; Ruas, Cassio V
Lima, CD, Brown, LE, Wong, MA, Leyva, WD, Pinto, RS, Cadore, EL, and Ruas, CV. Acute effects of static vs. ballistic stretching on strength and muscular fatigue between ballet dancers and resistance-trained women. J Strength Cond Res 30(11): 3220-3227, 2016-Stretching is used to increase joint range of motion, but the acute effects can decrease muscle strength. However, this may depend on the population or mode of stretching. The purpose of this study was to compare the acute effects of static vs. ballistic stretching on strength and muscular fatigue between ballet dancers and resistance-trained women. Fifteen resistance-trained women (age 23.8 ± 1.80 years, mass 67.47 ± 7.77 kg, height 168.30 ± 5.53 cm) and 12 ballet dancers (age 22.8 ± 3.04 years, mass 58.67 ± 5.65 kg, height 168.00 ± 7.69 cm) performed 5 days of testing. The first day was control (no stretching), whereas the other 4 days were static or ballistic stretching in a counterbalanced order. Range of motion, strength, and fatigue tests were also performed. Both groups demonstrated a significant decrease in hamstrings strength after static (102.71 ± 2.67 N·m) and ballistic stretching (99.49 ± 2.61 N·m) compared with control (113.059 ± 3.25 N·m), with no changes in quadriceps strength. For fatigue, only ballet dancers demonstrated a decrease from control (71.79 ± 4.88%) to ballistic (65.65 ± 8.19%), but no difference with static (65.01 ± 12.29%). These findings suggest that stretching decreases hamstrings strength similarly in ballet dancers and resistance-trained women, with no differences between modes of stretching. However, ballistic stretching only decreased muscular fatigue in ballet dancers, but not in resistance-trained women. Therefore, no stretching should be performed before strength performance. However, ballistic stretching may decrease acute muscular fatigue in ballet dancers.
Piao, YongJun; Choi, YounJung; Kim, JungJa; Kwan, TaeKyu; Kim, Nam-Gyun
Adequate postural balance depends on the spatial and temporal integration of vestibular, visual, and somatosensory information. Especially, the musculoskeletal function (range of joint, flexibility of spine, muscular strength) is essential in maintaining the postural balance. Muscular strength training methods include the use of commercialized devices and repeatable resistance training tools (rubber band, ball, etc). These training systems cost high price and can't control of intensity. Thus we suggest a new training system which can adjust training intensity and indicate the center of pressure of a subject while the training was passively controlled by applying controlled electric current to the Magneto- Rheological damper. And we performed experimental studies on the muscular activities in the lower extremities during maintaining, moving and pushing exercises on an unstable platform with Magneto rheological dampers. A subject executed the maintaining, moving and pushing exercises which were displayed in a monitor. The electromyographic signals of the eight muscles in lower extremities were recorded and analyzed in the time and frequency domain: the muscles of interest were rectus femoris, biceps femoris, tensor fasciae latae, vastus lateralis, vastus medialis, gastrocnemius, tibialis anterior, and soleus. The experimental results showed the difference of muscular activities at the four moving exercises and the nine maintaining exercises. The rate of the increase in the muscular activities was affected by the condition of the unstable platform with MR dampers for the maintaining and moving exercises. The experimental results suggested the choice of different maintaining and moving exercises could selectively train different muscles with varying intensity. Furthermore, the findings also suggested the training using this system can improve the ability of postural balance.
... are no known cures for the various muscular dystrophies. The goal of treatment is to control symptoms. Physical therapy may help maintain muscle strength and function. Leg braces and a wheelchair ...
Ratamess, Nicholas A; Beller, Noah A; Gonzalez, Adam M; Spatz, Gregory E; Hoffman, Jay R; Ross, Ryan E; Faigenbaum, Avery D; Kang, Jie
The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects' peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s(-1) [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey's post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key pointsMultiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women.Multiple-joint isokinetic resistance training increased 1RM strength in the bench press (by
Ratamess, Nicholas A.; Beller, Noah A.; Gonzalez, Adam M.; Spatz, Gregory E.; Hoffman, Jay R.; Ross, Ryan E.; Faigenbaum, Avery D.; Kang, Jie
The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM) strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT) or a non-exercising control group (CTL). The IRT group underwent 6 weeks of training (2 days per week) consisting of 5 sets of 6-10 repetitions at 75-85% of subjects’ peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s-1 [3-sec concentric (CON) and 3-sec eccentric (ECC) phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey’s post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg), 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg), and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions) increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women. Key points Multiple-joint isokinetic resistance training increases dynamic maximal muscular strength, local muscular endurance, and maximal isokinetic strength in women. Multiple-joint isokinetic resistance training increased 1RM strength in the bench press
Grgic, Jozo; Schoenfeld, Brad J; Davies, Timothy B; Lazinica, Bruno; Krieger, James W; Pedisic, Zeljko
Current recommendations on resistance training (RT) frequency for gains in muscular strength are based on extrapolations from limited evidence on the topic, and thus their practical applicability remains questionable. To elucidate this issue, we conducted a systematic review and meta-analysis of the studies that compared muscular strength outcomes with different RT frequencies. To carry out this review, English-language literature searches of the PubMed/MEDLINE, Scopus, and SPORTDiscus databases were conducted. The meta-analysis was performed using a random-effects model. The meta-analysis models were generated with RT frequencies classified as a categorical variable as either 1, 2, 3, or 4+ times/week, or, if there were insufficient data in subgroup analyses, the training frequencies were categorized as 1, 2, or 3 times/week. Subgroup analyses were performed for potential moderators, including (1) training volume; (2) exercise selection for the 1 repetition maximum (RM) test (for both multi-joint and single-joint exercises); (3) upper and lower body strength gains; (4) training to muscular failure (for studies involving and not involving training to muscular failure); (5) age (for both middle-aged/older adults and young adults); and (6) sex (for men and for women). The methodological quality of studies was appraised using the modified Downs and Black checklist. A total of 22 studies were found to meet the inclusion criteria. The average score on the Downs and Black checklist was 18 (range 13-22 points). Four studies were classified as being of good methodological quality, while the rest were classified as being of moderate methodological quality. Results of the meta-analysis showed a significant effect (p = 0.003) of RT frequency on muscular strength gains. Effect sizes increased in magnitude from 0.74, 0.82, 0.93, and 1.08 for training 1, 2, 3, and 4+ times per week, respectively. A subgroup analysis of volume-equated studies showed no significant effect (p
SÃ©rgio Leite Rodrigues
Full Text Available Aim: To determine which variable (forced expiratory volume in 1 second (FEV1, partial pressure of oxygen in arterial blood (PaO2, nocturnal hypoxaemia and muscular strength of femoral quadriceps can predict the distance walked in the six-minute walk test (6MWT by COPD patients. Methods: A cross-sectional and observational study of thirty patients referred to a pulmonary rehabilita tion programme at a university hospital. Lung function was evaluated by spirometry, arterial blood gas analysis and nocturnal oximetry. Muscle function was evaluated by quadriceps strength and functional capacity by the 6MWT. Results: Bivariate regression analysis showed that quadriceps strength, was the only variable to correlate significantly with the distance walked in the 6MWT (pÂ =Â 0.002, accounting for 38% of the 6MWT variance. The statistical relationship established for these variables was 1Â kg of quadriceps strength equalled 5.9 metres walked in the 6MWT. Conclusions: Our results showed the importance of lower limb muscle strength in submaximal exercise testing. We conclude that femoral quadriceps muscle strength is the only one of the variables studied which can predict the distance COPD patients walk in the 6MWT. Resumo: Objectivo: Determinar que variÃ¡vel entre o volume expirado forÃ§ado no primeiro segundo (VEF1, a pressÃ£o parcial do oxigÃ©nio no sangue arterial (PaO2, a hipoxemia nocturna e a forÃ§a muscular do quadricÃpite femoral pode predizer a distÃ¢ncia percorrida no teste de caminhada de seis minutos (TC6 em doentes com DPOC. Doentes e mÃ©todos: Um estudo observacional do tipo transversal, envolvendo trinta doentes encaminhados a um programa de reabilitaÃ§Ã£o pulmonar de um hospital universitÃ¡rio. A funÃ§Ã£o pulmonar foi avaliada por espirometria, gasometria arterial e oximetria nocturna. A funÃ§Ã£o muscular pela forÃ§a muscular do quadricÃpite femoral e a avaliaÃ§Ã£o da capacidade funcional pelo TC6
Moita, João P; Nunes, Alexandre; Esteves, José; Oliveira, Raul; Xarez, Luis
The physical demands placed on dancers put them at significant risk for injury, with rates similar to ones sustained by athletes in sports at the same level of performance. Muscle strength has been suggested to play a preventative role against injury in dancers. To systematically search and examine the available evidence on the protective role of muscle strength in dance injuries. Five electronic databases and two dance-specific science publications were screened up to September 2015. Study selection was based on a priori inclusion criteria on the relation between muscle strength components and injuries. Methodologic quality and level of evidence were assessed using the Downs and Black (DB) checklist and the Oxford Centre of Evidence-Based Medicine (OCEBM) 2011 model. From 186 titles found, only 8 studies met the inclusion criteria and were considered for review. Because of the significant heterogeneity of the included studies, meta-analysis was deemed inappropriate. The DB quality assessment results ranged from 18.7% to 75% (mean 42.3±16.9) and the OCEBM between 2b and 4. Some level 2b evidence from 2 studies suggested that pre-professional ballet dancers who get injured exhibit lower overall muscle strength scores on the lower extremity, and that lower extremity power gains may be associated with decreased bodily pain but not injury rate. Although there might be an association trend toward low muscle strength and dance injuries, the nature of that relation remains unclear, and presently the state of knowledge does not provide a solid basis for designing interventions for prevention.
Vera, Jesús; Jiménez, Raimundo; García-Ramos, Amador; Cárdenas, David
The positive association between intraocular pressure (IOP) and relative maximum force may have relevance for exercise recommendations when IOP is a concern. The relationship between exercise and IOP has been approached in several studies. However, the influence of muscle function on IOP remains underexplored. This study aimed to determine the relationship between the maximal mechanical capabilities of muscles to generate force, velocity, and power with IOP. Sixty-five physically active males participated in this cross-sectional study. Baseline IOP measures were obtained by rebound tonometry, and participants performed an incremental loading test in the ballistic bench press. Baseline IOP showed a strong positive correlation with relative maximum force (r65 = 0.85, P .05). There is a positive association between greater upper-body power and strength with higher baseline IOP, which might have important implications in the management of ocular health and especially in individuals constantly involved in resistance training programs (e.g., military personnel, weightlifters). The possible protective effect of high fitness level on the acute IOP response to strength exercise needs to be addressed in future studies.
Olagbegi Oladapo Michael
Full Text Available Purpose. Backward descent of stairs is associated with improved muscle strength and reduced joint stress, but the effect of backward ascent of stairs on lower limb muscle strength has not been reported. This study compared the effects of forward and backward stair climbing on lower limb muscle strength in apparently healthy young adults. Methods. The total of 31 young volunteers were allocated to either forward or backward stair climbing group (n = 16 and 15, respectively. Dynamic quadriceps and hamstring muscle strength was assessed in addition to thigh girth at baseline and at weeks 4 and 8 with the use of the repetitive maximum method and tape measure, respectively. Results. Between baseline and week 8, muscular strength in both groups (quadriceps: 14.4 ± 3.6 to 16.4 ± 3.4 kg; 14.0 ± 2.9 to 15.3 ± 2.7 kg; hamstring: 12.2 ± 3.2 to 13.4 ± 3.2; 11.7 ± 2.5 to 12.9 ± 2.7 kg increased significantly (p 0.05. The groups were comparable in all three measures post intervention. Conclusions. Forward and backward stair climbing protocols are effective for improving the dynamic strength of the hamstring and quadriceps muscles of apparently healthy young adults. Thus, either protocol could be used for the improvement of lower limbs dynamic muscle strength.
Sveen, Marie Louise; Jeppesen, Tina D; Hauerslev, Simon
with the dystrophinopathy, Becker muscular dystrophy (BMD). Eleven patients with BMD and seven matched, healthy subjects cycled 50, 30 min sessions at 65% of their maximal oxygen uptake (VO(2max)) over 12 weeks, and six patients continued cycling for 1 year. VO(2max), muscle biopsies, echocardiography, plasma creatine...
Yu, Chang Ho; Piao, Young Jun; Kim, Kyung; Kwon, Tae Kyu
A new training system that can adjust training intensity and indicate the center pressure of a subject was proposed by applying controlled electric current to the Magneto-Rheological damper. The experimental studying on the muscular activities were performed in lower extremities during maintaining and moving exercises, which were processed on an unstable platform with Magneto rheological dampers and recorded in a monitor. The electromyography (EMG) signals of the eight muscles in lower extremities were recorded and analyzed in certain time and frequency domain. Muscles researched in this paper were rectus femoris (RF), biceps femoris (BF), tensor fasciae latae (TFL), vastuslateralis (VL), vastusmedialis (VM), gastrocnemius (Ga), tibialis anterior (TA), and soleus (So). Differences of muscular activities during four moving exercises were studied in our experimental results. The rate of the increment of the muscular activities was affected by the condition of the unstable platform with MR dampers, which suggested the difference of moving exercises could selectively train each muscle with varying intensities. Furthermore, these findings also proposed that this training system can improve the ability of postural balance.
Keogh, Justin W L; Marnewick, Michel C; Maulder, Peter S; Nortje, Jacques P; Hume, Patria A; Bradshaw, Elizabeth J
The present study assessed the anthropometric profile (International Society for the Advancement of Kinanthropometry protocol), flexibility, muscular strength, and endurance of 20 male golfers. These data were collected in order to determine: a) the relationship between these kinanthropometric measures and clubhead velocity; and b) if these measures could distinguish low-handicap (LHG) and high-handicap (HHG) golfers. Ten LHG (handicap of 0.3 +/- 0.5) and 10 HHG (handicap of 20.3 +/- 2.4) performed 10 swings for maximum velocity and accuracy with their own 5-iron golf club at a wall-mounted target. LHG hit the target significantly more (115%) and had a 12% faster clubhead velocity than HHG (p bench press strength and longer (5%) upper am and total arm (4%) length and less (24%) right hip internal rotation than HHG (0.01 velocity (p bench press and hack squat strength as well as upper arm and total arm length also approaching significance (0.01 bench press strength and longer arms may therefore be at a competitive advantage, as these characteristics allow the production of greater clubhead velocity and resulting ball displacement. Such results have implications for golf talent identification programs and for the prescription and monitoring of golf conditioning programs. While golf conditioning programs may have many aims, specific trunk rotation exercises need to be included if increased clubhead velocity is the goal. Muscular hypertrophy development may not need to be emphasized as it could reduce golf performance by limiting range of motion and/or increasing moment of inertia.
Moran, Jason; Sandercock, Gavin; Ramirez-Campillo, Rodrigo; Clark, Cain C T; Fernandes, John F T; Drury, Benjamin
Resistance training is an effective way to enhance strength in female youth but, to date, no researcher has meta-analysed its effect on muscular strength in that population. This meta-analysis characterised female youths' adaptability to resistance training (RT). A second objective was to highlight the limitations of the body of literature with a view to informing future research. Google Scholar, PubMed, Web of Science. Resistance training interventions in healthy females with a mean age between 8 and 18 years. Programmes of between 4 and 16 weeks' duration that included a control group. The inverse-variance random effects model for meta-analyses was used because it allocates a proportionate weight to trials based on the size of their individual standard errors and facilitates analysis whilst accounting for heterogeneity across studies. Effect sizes, calculated from a measure of muscular strength, are represented by the standardised mean difference and are presented alongside 95% confidence intervals. The magnitude of the main effect was 'small' (0.54, 95% confidence interval: 0.23-0.85). Effect sizes were larger in older (> 15 years; ES = 0.72 [0.23-1.21] vs. 0.38 [- 0.02-0.79]), taller (> 163 cm; ES = 0.67 [0.20-1.13] vs. 0.55 [0.08-1.02]) and heavier (< 54 kg; ES = 0.67 [0.30-1.03] vs. 0.53 [- 0.00-1.06]) participants. Resistance training is effective in female youth. These findings can be used to inform the prescription of RT in female youth.
Seiler, Hilde Lohne; Torstveit, Monica Klungland; Anderssen, Sigmund A.
Published versiom of an article in the journal:Journal of Aging and Physical Activity. Also available from Human Kinetics: http://http://journals.humankinetics.com/japa-back-issues/japa-volume-21-issue-1-january/traditional-versus-functional-strength-training-effects-on-muscle-strength-and-power-in-the-elderly The aim was to determine whether strength training with machines vs. functional strength training at 80% of one-repetition maximum improves muscle strength and power among the elderl...
San. Zhen Qiang
Full Text Available Purpose: substantiation of health related power lifting training methodic for universities students, who have disorders of muscular skeletal apparatus. Material: in experimental researches 126 students of 18-24 years’ age, having disorders of muscular skeletal apparatus, participated. With the help of testing we registered changes of students’ functional, physical and psycho-physiological fitness indicators. Results: optimal correlation of specific and non specific loads was found: 60% of specific and 40% of non specific. It is recommended to follow certain correlation of exercises in easy and complicated conditions: for first year students - 3:2; for second year students - 3:2; for third year - 2:3; for forth year - 2:3; for fifth year students - 1:3. Specific only for power lifting conditions and temps of students’ (with muscular skeletal apparatus affections functional, physical and psycho-physiological fitness improvement were determined. Conclusions: The requirements of the training methodic envisage correction of loads for bringing every indicator on proper level.
Full Text Available Strength imbalances between the hamstrings and quadriceps are an essential predictor for hamstring strain in soccer. The study aimed to investigate and compare the muscle strength imbalances of professional soccer players of different performance levels. One hundred and fifty nine senior male professional soccer players from first (n = 75 and second league (n = 84 Portuguese clubs participated in this study. Muscle strength was evaluated with a REV9000 isokinetic dynamometer. Maximal peak torque data were used to calculate quadriceps and hamstrings strength during concentric and eccentric actions, bilateral asymmetry, conventional strength ratios and dynamic control ratios. Second league athletes produced slightly lower conventional strength ratios in the right and left legs (ES = 0.22, p = 0.17 and ES = 0.36, p = 0.023, respectively compared to the first league athletes. No significant differences were found in dynamic control ratios or in bilateral asymmetry among first and second league athletes. These findings do not show a clear link between the competitive level and injury risk in soccer players. However, some of the differences found, particularly in conventional strength ratios, highlight the importance of performing off-season and pre-season strength assessments to prescribe and adjust individual strength training programs among professional soccer players.
Andrea Silveira da Fontoura
ó significativamente (p The strength trainability in children has been widely explored, however, there is still a questioning with regard to how strength decreases when they stop training. The objective of this study was to evaluate the effect of 12 weeks of muscular strength detraining of boys trained for 12 weeks. Seven prepubertal boys (EX 9.4 ± 1.6 years of age trained three series of 15 repetitions, three times a week for 12 weeks. The training, supervised and developed in equipments, consisted of eight exercises including knee extension (KE and elbow flexion (EF. The 1-RM test of NE and EF was performed before and after training and 12 weeks after detraining. A similar group of boys (n = 7, 9.7 ± 1.7 years, who did not train served as control (CO. After training, the group EX increased (p 0,05. When corrected by the body weight and by the lean body mass (LBM, the 1-RM of NE decreased significantly (p > 0,05 from 0.64 ± 0.1 to 0.45 ± 0.1 and from 0.83 ± 0.2 to 0.61 ± 0.2 of the body weight and LBM, respectively. The EF strength did not decrease significantly when corrected by the body weight and LBM. The strength levels did not change in the first 12 weeks for group CO, however, after 24 weeks, it presented an increase of 41% in the 1-RM of KE and 53% in EF. One concludes that, after detraining, the muscular strength presented no significant reduction in absolute values; the results are significant only when corrected by weight and LBM and it is only evidenced for the lower limbs.
Nicholas A. Ratamess, Noah A. Beller, Adam M. Gonzalez, Gregory E. Spatz, Jay R. Hoffman, Ryan E. Ross, Avery D. Faigenbaum, Jie Kang
Full Text Available The transfer of training effects of multiple-joint isokinetic resistance training to dynamic exercise performance remain poorly understood. Thus, the purpose of the present study was to investigate the magnitude of isokinetic and dynamic one repetition-maximum (1RM strength and local muscular endurance increases after 6 weeks of multiple-joint isokinetic resistance training. Seventeen women were randomly assigned to either an isokinetic resistance training group (IRT or a non-exercising control group (CTL. The IRT group underwent 6 weeks of training (2 days per week consisting of 5 sets of 6-10 repetitions at 75-85% of subjects’ peak strength for the isokinetic chest press and seated row exercises at an average linear velocity of 0.15 m s-1 [3-sec concentric (CON and 3-sec eccentric (ECC phases]. Peak CON and ECC force during the chest press and row, 1RM bench press and bent-over row, and maximum number of modified push-ups were assessed pre and post training. A 2 x 2 analysis of variance with repeated measures and Tukey’s post hoc tests were used for data analysis. The results showed that 1RM bench press (from 38.6 ± 6.7 to 43.0 ± 5.9 kg, 1RM bent-over row (from 40.4 ± 7.7 to 45.5 ± 7.5 kg, and the maximal number of modified push-ups (from 39.5 ± 13.6 to 55.3 ± 13.1 repetitions increased significantly only in the IRT group. Peak isokinetic CON and ECC force in the chest press and row significantly increased in the IRT group. No differences were shown in the CTL group for any measure. These data indicate 6 weeks of multiple-joint isokinetic resistance training increases dynamic muscle strength and local muscular endurance performance in addition to specific isokinetic strength gains in women.
Monique Opuszcka Campos
Full Text Available The aim of this systematic review was to summarize available scientific evidence on the utilization of whole body vibration as an alternative method to promote effective modifications on muscle strength and power in the aging population. Scientific studies were retrieved from the following databases: Medline, Scielo, Lillacs, Cochrane Library, PEDro and Science Citation Index. The PEDro scale was used to assess the quality of the included studies, while content went through a critical analysis. From the 91 studies retrieved, 75 were excluded and 16 attended the selection criteria. From the16, the majority (68.8% presented from moderate to high methodological quality. Whole-body vibration associated to both isometric and dynamic exercises seemed to constitute an alternative for therapeutic intervention to improve muscular strength and power of healthy elderly. However, due to the characteristics of the designs of the studies reviewed and the threats to their internal validity (i.e., the absence of the control condition to the vibratory stimulus it was challenging to establish the additional effects of the whole-body vibration on the target population. Divergent findings were found for the whole-body vibration effect on muscular power. It is still necessary to conduct randomized control trials to establish the real effectiveness of this kind of intervention.
Full Text Available Lauren R Tapp,1,3 Joseph F Signorile1,2,41Departments of Kinesiology and Sport Sciences, Coral Gables, 2Center on Aging, University of Miami Miller School of Medicine, Miami, FL, 3Department of Kinesiology, Temple University, Philadelphia, PA, 4Geriatric Research, Education, and Clinical Center, Bruce W Carter Department of Veterans Affairs Medical Center, Miami, FL, USAAbstract: The purpose of this pilot study was to evaluate the effectiveness of whole body vibration (WBV training as a modality for inducing changes in body composition, cardiovascular condition, and muscular strength in sedentary postmenopausal women. WBV training was compared with other training regimens, ie, aerobic training and circuit resistance training, commonly used to promote weight loss, cardiovascular conditioning, and muscular strength. Postmenopausal women (aged 48–60 years were randomly assigned to WBV training, circuit resistance training, or aerobic training. Participants trained three times per week for 8 weeks. The training regimens were progressive in nature, with increases in training intensity and duration occurring throughout the 8-week period. Body composition was assessed using dual-energy X-ray absorptiometry analyses. A modified Bruce treadmill protocol was used to assess aerobic capacity (VO2peak and time to peak exhaustion. Upper and lower body strengths were determined by one repetition maximum (1-RM chest and leg presses, respectively. Variables were analyzed using separate 3 (exercise mode × 2 (time repeated-measures analysis of variance with effect sizes due to the small sample size. No significant main effects or interactions were seen for any body composition variable; however, moderate to large effect sizes (η2=0.243 and η2=0.257 were detected regarding interactions for percent body fat and lean body mass favoring aerobic training and circuit resistance training. For VO2peak, no significant main effects or interactions were detected (time
Respuesta hemodinámica con el entrenamiento en resistencia y fuerza muscular de miembros superiores en rehabilitación cardiaca Hemodynamic response to training in resistance and muscular strength of upper limbs in cardiac rehabilitation
Diana M Camargo
de 1,92 ± 2,49 lb (pAntecedentes: training of muscular strength in patients with cardiovascular events was totally contraindicated because of the risk of incrementing the systolic and diastolic arterial pressure values, as well as the submission to a myocardial overload. Objective: evaluate the hemodynamic response (heart rate, arterial pressure during the resistance to muscular strength training in patients assisting to a heart rehabilitation program. Design: quasi experimental prospective study. Setting: resistance training to muscular strength in upper limbs to patients during stage II of cardiac rehabilitation was realized. Subjects: 175 patients were included. 135 men and 40 women with mean age 58.79 years with coronary disease, with or without revascularization procedures, valvular surgery, syncope and surgical correction of congenital heart disease. Procedure: previous aerobic training (treadmill or static bicycle, muscular strength evaluation was realized through maximal repetition and the strength training was initiated at 30%-50% of this, in a three different exercise circuit in upper limbs, 10 repetitions in three series with a twice a week frequency. Besides, monitoring of heart frequency, electrocardiogram by telemetry (V5, arterial pressure recording before, during and after the session, and subjective perception of the effort by the Borg scale were made, and signs and symptoms of intolerance to the activity or decompensation were observed. For the statistical analysis, measures of central tendency with the cardiovascular changes were used and in order to compare the change in muscular strength, a paired t test with significance level 0.05 was utilized. Results: mean muscular strength with maximal repetition evidenced a significant increase of 1.92 ± 2.49 lb (p<0.001 in the general population, with an increment of 2.03 ± 2.57 lb (p<0.001 in men and of 1.46 ± 2.1 lb (p<0.001 in women. The muscular resistance training was realized with a mean load of
Sakamaki-Sunaga, Mikako; Min, Seokki; Kamemoto, Kayoko; Okamoto, Takanobu
The present study investigated how different training frequencies during menstrual phases affect muscle hypertrophy and strength. Fourteen eumenorrheic women performed 3 sets of arm curls (8-15 repetitions) until failure for 12 weeks. Depending on the menstrual cycle phase, each subject trained each arm separately after either a 3- or a 1-d·wk training protocol during the follicular phase (FP-T) and a 3- or 1-d·wk training protocol during the luteal phase (LP-T). Cross-sectional area (CSA), 1 repetition maximum, and maximum voluntary contraction significantly increased 6.2 ± 4.4, 36.4 ± 11.9, and 16.7 ± 5.6%, respectively (p ≤ 0.05 vs. before training), in the FP-T group and 7.8 ± 4.2, 31.8 ± 14.1, and 14.9 ± 12.7%, respectively (p ≤ 0.05 vs. before training), in the LP-T group. Changes in CSA between the FP-T and the LP-T groups significantly and positively correlated (r = 0.54, p ≤ 0.05). There were no major differences among the different training protocols with regard to muscle hypertrophy and strength. Therefore, we suggest that variations in female hormones induced by the menstrual cycle phases do not significantly contribute to muscle hypertrophy and strength gains during 12 weeks of resistance training.
Camile Ludovico Zamboti
Full Text Available Abstract Introduction: Patellofemoral Pain Syndrome (PFPS is associated with anterior knee pain, changes in functional capacity, balance and muscle strength disorders. Objective: To quantify pain, functional capacity, strength in quadriceps (Q, gluteus medium (GM, hip external rotator (ER muscles and balance in sedentary women with PFPS. Methods: Twenty sedentary women, aged 18 to 25 years, were divided into two groups: PFPS (N=10 and control group (N=10. All the volunteers answered the items of the Visual Analogue Scale (VAS, the Lysholm Knee Score Scale, the Anterior Knee Pain Scale (AKPS, and the Lower Extremity Functional Scale (LEFS. The participants performed the following tests: maximal voluntary isometric contraction measured by dynamometry; postural balance using the Star Excursion Balance Test (SEBT and a force platform. Statistical analyses were performed using the Shapiro Wilk test, the Mann Whitney U test and Spearman’s correlation coefficient. Data were submitted to SPSS 20 software. Results: The PFPS group presented greater pain, balance impairment and higher average velocity of oscillation; however, no differences were observed in Q, GM and RE muscle strength and in balance analyzed by SEBT. Conclusion: Women with PFPS exhibited greater pain, worse functional capacity and body balance. Moderate correlation between both balance tests suggests the use of SEBT when the force platform is not available, which could facilitate and highlight the importance of clinical diagnosis with regard to postural balance.
Trudelle-Jackson, Elaine; Jackson, Allen W; Morrow, James R
We examined the relations of meeting or not meeting the 2008 Physical Activity Guidelines for Americans recommendations for muscular strengthening activities with percentage of body fat, body mass index (BMI; defined as weight in kilograms divided by height in meters, squared), muscular strength, and obesity classification in women. We analyzed data on 918 women aged 20 to 83 years in the Women's Injury Study from 2007 to 2009. A baseline orthopedic examination included measurement of height, body weight, skinfolds, and muscle strength. Women who met muscle strengthening activity recommendations had significantly lower BMI and percentage of body fat and higher muscle strength. Women not meeting those recommendations were more likely to be obese (BMI ≥ 30) compared with women who met the recommendations after we adjusted for age, race, and aerobic physical activity (odds ratio = 2.28; 95% confidence interval = 1.61, 3.23). There was a small but significant positive association between meeting muscle strengthening activity recommendations and muscular strength, a moderate inverse association with body fat percentage, and a strong inverse association with obesity classification, providing preliminary support for the muscle strengthening activity recommendation for women.
Kim, Yong-Youn; Park, Si-Eun
[Purpose] The purpose of this study was to assess the effect of whole-body vibration exercise and plyometric exercise on female volleyball players. [Subjects and Methods] Subjects were randomly allocated to two exercise groups (whole-body vibration exercise group and plyometric exercise group). The exercise was conducted three times each week for 8 weeks. Isokinetic muscular strength, jumping performance, and balance were measured before starting the exercise and after finishing the 8 weeks o...
Ribeiro,Fabrício Miranda; Novaes,Jefferson da Silva; Lemos,Adriana; Simão,Roberto
O objetivo do presente estudo foi determinar a reprodutibilidade de um instrumento de medida da potência muscular (PM), o Power Control TechnoGym@, através de um teste de PM. Foram avaliadas 15 mulheres (26,2 ± 1,9 anos) experientes em treinamento de força em dois exercícios, a remada sentada e a puxada aberta pela frente no pulley alto, através do teste de 1RM. Foram determinadas a carga máxima e a carga que gerou a potência máxima em cada exercício. Após a obtenção da carga que gerou...
Broverman, A.Y.; Hill, R.E.
Crowbarring the output of a power supply serves to electrically protect the power supply's load. At the same time, however, the supply's windings are subjected to the electromagnetic forces of a partial short circuit. Because pulsed power supplies are frequently crowbarred as a normal part of the duty cycle, it is essential that their transformer windings be designed to repetitively withstand short circuit forces. If not provided for, crowbar or short circuit forces can irreparably damage the transformer's coils. These power supplies are intended for fusion applications. 2 refs
Kim, Yong-Youn; Park, Si-Eun
[Purpose] The purpose of this study was to assess the effect of whole-body vibration exercise and plyometric exercise on female volleyball players. [Subjects and Methods] Subjects were randomly allocated to two exercise groups (whole-body vibration exercise group and plyometric exercise group). The exercise was conducted three times each week for 8 weeks. Isokinetic muscular strength, jumping performance, and balance were measured before starting the exercise and after finishing the 8 weeks of exercise. [Results] Measurements of isokinetic muscular strength revealed that the whole-body vibration exercise group showed significant increase after the exercise. However, the plyometric exercise group had no significant increase in lumbar flexion, extension, and knee flexion. Measurements of vertical jumping revealed that, the whole-body vibration exercise group had no significant increase after the exercise. However, the plyometric exercise group showed significant increase. Measurements of balance revealed that, the whole-body vibration exercise group showed significant increase. However, the plyometric exercise group showed no significant increase. [Conclusion] Although both whole-body vibration and plyometric exercises are effective intervention methods, the two methods have different effects on the improvement of isokinetic muscular strength, jumping performance, and balance of female volleyball players.
Full Text Available Objective. To examine the effects of a 12-week Hatha yoga intervention on cardiorespiratory endurance, muscular strength and endurance, and flexibility in Chinese adults. Methods. 173 adults (aged 52.0 ± 7.5 years were assigned to either the yoga intervention group (n=87 or the waitlist control group (n=86. 19 dropped out from the study. Primary outcomes were changes in cardiorespiratory endurance (resting heart rate (HR and maximal oxygen uptake (VO2max, muscular strength and endurance (curl-up and push-up tests, and lower back and hamstring flexibility (the modified back-saver sit-and-reach (MBS test. Results. Compared to controls, the yoga group achieved significant improvements in VO2max (P<0.01, curl-up (P<0.05 and push-up (P<0.001 tests, and the MBS left and right leg tests (both P<0.001 in both genders. Significant change was also found for resting HR between groups in women (P<0.05 but not in men. Further analysis comparing participants between younger and older subgroups yielded similar findings, except that the older participants in the yoga group failed to improve resting HR or the curl-up test versus control. Adherence (89% and attendance (94% were high. No serious adverse events occurred. Conclusion. A 12-week Hatha yoga intervention has favorable effects on cardiorespiratory endurance, muscular strength and endurance, and flexibility in Chinese adults.
Impacto de oito semanas de treinamento com pesos sobre a força muscular de homens e mulheres Impacto de ocho semanas de entrenamiento con pesos sobre la fuerza muscular de hombres y mujeres Impact of an eight-week weight training program on the muscular strength of men and women
Raphael Mendes Ritti Dias
Full Text Available O objetivo do presente estudo foi verificar o impacto de oito semanas de treinamento com pesos (TP sobre a força muscular. Para tanto, 23 homens (20,7 ± 1,7 anos e 15 mulheres (20,9 ± 2,1 anos, aparentemente saudáveis e moderadamente ativos (atividade física regular El objetivo del presente estudio fué el de verificar el impacto de ocho semanas de entrenamiento con pesos (TP sobre la fuerza muscular. Para ello, 23 hombres (20,7 ± 1,7 años y 15 mujeres (20,9 ± 2,1 años, aparentemente saludables y moderadamente activos (atividad física regular The objective of the present study was to verify the impact of an eight-week weight training program (WT on the muscular strength. To do so, 23 men (20.7 ± 1.7 years and 15 women (20.9 ± 2.1 years, apparently healthy and moderately active (regular physical activity < 2 times a week were submitted to a WT program composed of 10 exercises for the different muscular groups during eight consecutive weeks. Three series of 8-12 RM were performed in each exercise in three weekly sessions with intervals each 48 hours. The pre and post-training muscular strength was determined by means of 1-RM tests in bench press, squat and arm curl exercises after five familiarization sessions. Increases on the muscular strength were verified in both genders in all exercises investigated as well as in the total amount of load lifted (P < 0.01. Although men presented higher absolute strength when compared to women in all exercises evaluated, the gains observed along time were higher for women (14.7 vs. 7.6% in squat; 17.2 vs. 11.0% bench press; 20.4 vs. 14.0% in arm curl. The results suggest that the eight-week WT period seems to be sufficient to promote significant modifications in the muscular strength of men and women in different body segments (lower limbs, trunk and upper limbs.
Golem, Devon L; Arent, Shawn M
Improvements in muscular power and anaerobic performance have resulted from the use of jaw-repositioning mouth guards designed with advanced dental techniques. The high cost of such techniques has dissuaded the widespread use. Recently, more affordable, over-the-counter (OTC) jaw-repositioning mouth guards have become available. The primary objective of this study was to examine the effects of 2 OTC jaw-repositioning mouth guards on muscular power and strength performance in college-aged male athletes. It was hypothesized that similar to previous observations with advanced dentistry-designed mouth guards, OTC jaw-repositioning mouth guards would impart positive effects on muscular power but not have any effect on muscular strength. Secondary objectives of this study included the examination of the effects of 2 OTC jaw-repositioning mouth guards on other variables related to athletic performance. Male collegiate athletes (N = 20) participated in 4 separate testing sessions that consisted of assessment of muscular power, dynamic balance, flexibility, agility, and muscular strength. The 4 conditions, 1 per testing session, were assigned in a randomized order and consisted of a no-mouth guard control (CON), a placebo mouth guard, a self-adapted jaw-repositioning mouth guard (SA), and a custom-fitted jaw-repositioning mouth guard (CF). No significant differences were observed between conditions in muscular power (p = 0.78), dynamic balance (p = 0.99), agility (p = 0.22), or muscular strength (p = 0.47). The CF had significantly lower hip flexion than the CON (p = 0.014) and had significantly greater lumbar spine lateral flexion compared with the SA condition (p = 0.054). However, these flexibility differences lack practical relevance as the effect sizes remain very small (ES = -0.27 and -0.14, respectively). In conclusion, the jaw-repositioning technique used in the design of these OTC mouth guards did not affect performance. It is important to note that negative
... following bands, the predicted or measured median field strength at any location on the geographical border... predicted or measured median field strength at any location on the geographical border of a licensee's... antenna mounting structure. (c) Power flux density limit for stations operating in the 746-757 MHz, 758...
Lustosa, Lygia P; Silva, Juscélio P; Coelho, Fernanda M; Pereira, Daniele S; Parentoni, Adriana N; Pereira, Leani S M
Frailty syndrome in elderly people is characterized by a reduction of energy reserves and also by a decreased of resistance to stressors, resulting in an increase of vulnerability. The aim of this study was to verify the effect of a muscle-strengthening program with load in pre-frail elder women with regards to the functional capacity, knee extensor muscle strength and their correlation. Thrity-two pre-frail community-dwelling women participated in this study. Potential participants with cognitive impairment (MEEM), lower extremities orthopedic surgery, fractures, inability to walk unaided, neurological diseases, acute inflammatory disease, tumor growth, regular physical activity and current use of immunomodulators were excluded. All partcipants were evaluated by a blinded assessor using: Timed up and go (TUG), 10-Meter Walk Test (10MWT) and knee extensor muscle strength (Byodex System 3 Pro® isokinetic dynamometer at angular speeds of 60 and 180(0)/s). The intervention consisted of strengthening exercises of the lower extremities at 70% of 1RM, three times/ week for ten weeks. The statistical analysis was performed using the ANOVA and Spearman tests After the intervention, it was observed statistical significance on the work at 180(0)/s (F=12.71, p=0.02), on the power at 180(0)/s (F=15.40, p=0.02) and on the functional capacity (TUG, F=9.54, p=0.01; TC10, F=3.80, p=0.01). There was a good negative and statistically significant correlation between the TUG and work at 60(0)/s, such as the TUG and work at 180(0)/s (r=-0.65, p=0.01; r=-0.72, p=0.01). The intervention improved the muscular power and the functional capacity. The increase of the power correlated with function, which is an important variable of the quality of life in the pre-frail elders. Article registered in the ISRCT register under number ISRCTN62824599.
Full Text Available The Ras superfamily of guanosine-triphosphate (GTP-binding proteins regulates a diverse spectrum of intracellular processes involved in inflammation and fibrosis. Farnesythiosalicylic acid (FTS is a unique and potent Ras inhibitor which decreased inflammation and fibrosis in experimentally induced liver cirrhosis and ameliorated inflammatory processes in systemic lupus erythematosus, neuritis and nephritis animal models. FTS effect on Ras expression and activity, muscle strength and fibrosis was evaluated in the dy(2J/dy(2J mouse model of merosin deficient congenital muscular dystrophy. The dy(2J/dy(2J mice had significantly increased RAS expression and activity compared with the wild type mice. FTS treatment significantly decreased RAS expression and activity. In addition, phosphorylation of ERK, a Ras downstream protein, was significantly decreased following FTS treatment in the dy(2J/dy(2J mice. Clinically, FTS treated mice showed significant improvement in hind limb muscle strength measured by electronic grip strength meter. Significant reduction of fibrosis was demonstrated in the treated group by quantitative Sirius Red staining and lower muscle collagen content. FTS effect was associated with significantly inhibition of both MMP-2 and MMP-9 activities. We conclude that active RAS inhibition by FTS was associated with attenuated fibrosis and improved muscle strength in the dy(2J/dy(2J mouse model of congenital muscular dystrophy.
Muehlbauer, Thomas; Gollhofer, Albert; Granacher, Urs
The purpose of this study was to investigate the relationship between variables of static/dynamic balance, isometric strength, and power. Twenty-seven young healthy adults (mean age: 23 ± 4 years) performed measurements of static (unperturbed)/dynamic (perturbed) balance, isometric strength (i.e., maximal isometric torque [MIT]; rate of torque development [RTD] of the plantar flexor), and power (i.e., countermovement jump [CMJ] height and power). No significant associations were found between variables of static and dynamic balance (r = -0.090 to +0.329, p > 0.05) and between measures of static/dynamic balance and isometric strength (r = +0.041 to +0.387, p > 0.05) and static/dynamic balance and power (r = -0.076 to +0.218, p > 0.05). Significant positive correlations (r) were detected between variables of power and isometric strength ranging from +0.458 to +0.689 (p balance measures and between static/dynamic balance, isometric strength, and power variables implies that these capacities may be independent of each other and may have to be tested and trained complementarily.
Drake, David; Kennedy, Rodney; Wallace, Eric
Researchers and practitioners working in sports medicine and science require valid tests to determine the effectiveness of interventions and enhance understanding of mechanisms underpinning adaptation. Such decision making is influenced by the supportive evidence describing the validity of tests within current research. The objective of this study is to review the validity of lower body isometric multi-joint tests ability to assess muscular strength and determine the current level of supporting evidence. Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines were followed in a systematic fashion to search, assess and synthesize existing literature on this topic. Electronic databases such as Web of Science, CINAHL and PubMed were searched up to 18 March 2015. Potential inclusions were screened against eligibility criteria relating to types of test, measurement instrument, properties of validity assessed and population group and were required to be published in English. The Consensus-based Standards for the Selection of health Measurement Instruments (COSMIN) checklist was used to assess methodological quality and measurement property rating of included studies. Studies rated as fair or better in methodological quality were included in the best evidence synthesis. Fifty-nine studies met the eligibility criteria for quality appraisal. The ten studies that rated fair or better in methodological quality were included in the best evidence synthesis. The most frequently investigated lower body isometric multi-joint tests for validity were the isometric mid-thigh pull and isometric squat. The validity of each of these tests was strong in terms of reliability and construct validity. The evidence for responsiveness of tests was found to be moderate for the isometric squat test and unknown for the isometric mid-thigh pull. No tests using the isometric leg press met the criteria for inclusion in the best evidence synthesis. Researchers and
Saienko Vladimir Grigor'evich
Full Text Available Data are given meaningful totals display of force the muscle groups in athletes in the static mode. Displaying characteristics of muscle groups, hands (7, legs (5, trunk (2.The experiment involved 110 athletes (1-5 years experience training, age - 14-25 years old. Quantitative indicators, which reflect the individual level of informative power trained athletes. The optimum parameters of power qualities of athletes. Recommended use in training of special methods of strength training (isometric, concentric, eccentric, plyometric, isokinetic. In training must take into account the resistance, speed, joint angles, number of repetitions of the same approach.
Cormie, Prue; McGuigan, Michael R; Newton, Robert U
To determine whether the magnitude of improvement in athletic performance and the mechanisms driving these adaptations differ in relatively weak individuals exposed to either ballistic power training or heavy strength training. Relatively weak men (n = 24) who could perform the back squat with proficient technique were randomized into three groups: strength training (n = 8; ST), power training (n = 8; PT), or control (n = 8). Training involved three sessions per week for 10 wk in which subjects performed back squats with 75%-90% of one-repetition maximum (1RM; ST) or maximal-effort jump squats with 0%-30% 1RM (PT). Jump and sprint performances were assessed as well as measures of the force-velocity relationship, jumping mechanics, muscle architecture, and neural drive. Both experimental groups showed significant (P training with no significant between-group differences evident in either jump (peak power: ST = 17.7% +/- 9.3%, PT = 17.6% +/- 4.5%) or sprint performance (40-m sprint: ST = 2.2% +/- 1.9%, PT = 3.6% +/- 2.3%). ST also displayed a significant increase in maximal strength that was significantly greater than the PT group (squat 1RM: ST = 31.2% +/- 11.3%, PT = 4.5% +/- 7.1%). The mechanisms driving these improvements included significant (P force-velocity relationship, jump mechanics, muscle architecture, and neural activation that showed a degree of specificity to the different training stimuli. Improvements in athletic performance were similar in relatively weak individuals exposed to either ballistic power training or heavy strength training for 10 wk. These performance improvements were mediated through neuromuscular adaptations specific to the training stimulus. The ability of strength training to render similar short-term improvements in athletic performance as ballistic power training, coupled with the potential long-term benefits of improved maximal strength, makes strength training a more effective training modality for relatively weak individuals.
Jenkins, Nathaniel D M; Buckner, Samuel L; Bergstrom, Haley C; Cochrane, Kristen C; Goldsmith, Jacob A; Housh, Terry J; Johnson, Glen O; Schmidt, Richard J; Cramer, Joel T
To quantify the reliability of isometric leg extension torque (LEMVC), rate of torque development (LERTD), isometric handgrip force (HGMVC) and RFD (HGRFD), isokinetic leg extension torque and power at 1.05rad·s(-1) and 3.14rad·s(-1); and explore relationships among strength, power, and balance in older men. Sixteen older men completed 3 isometric handgrips, 3 isometric leg extensions, and 3 isokinetic leg extensions at 1.05rad·s(-1) and 3.14rad·s(-1) during two visits. Intraclass correlation coefficients (ICCs), ICC confidence intervals (95% CI), coefficients of variation (CVs), and Pearson correlation coefficients were calculated. LERTD demonstrated no reliability. The CVs for LERTD and HGRFD were ≤23.26%. HGMVC wasn't related to leg extension torque or power, or balance (r=0.14-0.47; p>0.05). However, moderate to strong relationships were found among isokinetic leg extension torque at 1.05rad·s(-1) and 3.14rad·s(-1), leg extension mean power at 1.05rad·s(-1), and functional reach (r=0.51-0.95; p≤0.05). LERTD and HGRFD weren't reliable and shouldn't be used as outcome variables in older men. Handgrip strength may not be an appropriate surrogate for lower body strength, power, or balance. Instead, perhaps handgrip strength should only be used to describe upper body strength or functionality, which may compliment isokinetic assessments of lower body strength, which were reliable and related to balance. Copyright © 2014 Elsevier Inc. All rights reserved.
Muehlbauer, Thomas; Besemer, Carmen; Wehrle, Anja; Gollhofer, Albert; Granacher, Urs
Deficits in strength, power and balance represent important intrinsic risk factors for falls in seniors. The purpose of this study was to investigate the relationship between variables of lower extremity muscle strength/power and balance, assessed under various task conditions. Twenty-four healthy and physically active older adults (mean age: 70 ± 5 years) were tested for their isometric strength (i.e. maximal isometric force of the leg extensors) and muscle power (i.e. countermovement jump height and power) as well as for their steady-state (i.e. unperturbed standing, 10-meter walk), proactive (i.e. Timed Up & Go test, Functional Reach Test) and reactive (i.e. perturbed standing) balance. Balance tests were conducted under single (i.e. standing or walking alone) and dual task conditions (i.e. standing or walking plus cognitive and motor interference task). Significant positive correlations were found between measures of isometric strength and muscle power of the lower extremities (r values ranged between 0.608 and 0.720, p power and balance (i.e. no significant association in 20 out of 21 cases). Additionally, no significant correlations were found between measures of steady-state, proactive and reactive balance or balance tests performed under single and dual task conditions (all p > 0.05). The predominately nonsignificant correlations between different types of balance imply that balance performance is task specific in healthy and physically active seniors. Further, strength, power and balance as well as balance under single and dual task conditions seem to be independent of each other and may have to be tested and trained complementarily. Copyright © 2012 S. Karger AG, Basel.
Musiige, Deogratius; Vincent, Laulagnet; Anton, François
This paper presents a new methodology for emulating the LTE modem power consumption, emitted SAR and RF signal strength when transmitting an LTE signal. The inputs of the methodology are: modem logical/protocol commands, time advance, near-field specifier, and antenna characteristics. The power...... emulation model(s) are computed by a two layer 451 neural network based on physical power measurements. SAR is emulated by polynomial interpolation models based on FDTD simulations. The accuracies of the mathematical function approximations for the emulation models of power and SAR are 5.19% and 3...
Full Text Available Abstract Background The purpose of this study was to compare the effects of supplementation with Gaspari Nutrition's SOmaxP Maximum Performance™ (SOmaxP versus a comparator product (CP containing an equal amount of creatine (4 g, carbohydrate (39 g maltodextrin, and protein (7 g whey protein hydrolysate on muscular strength, muscular endurance, and body composition during nine weeks of intense resistance training. Methods Using a prospective, randomized, double-blind design, 20 healthy men (mean ± SD age, height, weight, % body fat: 22.9 ± 2.6 y, 178.4 ± 5.7 cm, 80.5 ± 6.6 kg, 16.6 ± 4.0% were matched for age, body weight, resistance training history, bench press strength, bench press endurance, and percent body fat and then randomly assigned via the ABBA procedure to ingest 1/2 scoop (dissolved in 15 oz water of SOmaxP or CP prior to, and another 1/2 scoop (dissolved in 15 oz water during resistance exercise. Body composition (DEXA, muscular performance (1-RM bench press and repetitions to failure [RTF: 3 sets × baseline body weight, 60-sec rest between sets], and clinical blood chemistries were measured at baseline and after nine weeks of supplementation and training. Subjects were required to maintain their normal dietary habits and follow a specific, progressive overload resistance training program (4-days/wk, upper body/lower body split during the study. An intent-to-treat approach was used and data were analyzed via ANCOVA using baseline values as the covariate. Statistical significance was set a priori at p ≤ 0.05. Results When adjusted for initial differences, significant between group post-test means were noted in: 1-RM bench press (SOmaxP: 133.3 ± 1.3 kg [19.8% increase] vs. CP: 128.5 ± 1.3 kg [15.3% increase]; p Conclusions These data indicate that compared to CP, SOmaxP administration augments and increases gains in lean mass, bench press strength, and muscular performance during nine weeks of intense resistance training
Padilha, Camila S; Marinello, Poliana Camila; Galvão, Daniel A; Newton, Robert U; Borges, Fernando H; Frajacomo, Fernando; Deminice, Rafael
Muscle atrophy and strength decline are two of the most prominent characteristics in cancer patients undergoing cancer therapy, leading to decreased functional ability and reduced quality of life. Therefore, the aim is to systematically review research evidence of the effects of resistance exercise (RE) on lower-limb muscular strength, lean body mass (LBM), and body fat (BF) in cancer patients undertaking neoadjuvant or adjuvant therapy. This research was conducted using the following online database: Clinical Trial Register, Cochrane Trial Register, PubMed, SPORT Discus, and SciELO, from September 2014 until May 2015. We used the following keywords in various combinations with a systematic search: "Cancer therapy," "Wasting muscle," "Muscle loss," "Muscle function," "Neoadjuvant therapy," "Adjuvant thera-py," "Resistance Training," "Weight training," and "Exercise." After selection of 272 full-text articles, 14 publications were included in this meta-analysis. Resistance exercise (RE) during neoadjuvant or adjuvant therapy increased lower-limb muscular strength (mean: 26.22 kg, 95% CI [16.01, 36.43], heterogeneity: P = body mass (LBM) increased (mean 0.8 kg, 95% CI [0.7, 0.9], heterogeneity: P = 0.99, I 2 = 0%, P body fat (BF) (mean: -1.3 kg, 95% CI [-1.5, 1.1], heterogeneity: P = 0.93, I 2 = 0%, P cancer patients undergoing neoadjuvant and adjuvant therapy regardless of the kind of treatment. RE increases muscle strength, maintains LBM, and reduces BF in cancer patients undergoing adjuvant and neoadjuvant therapies. Cancer patients and survivors should consider undertaking RE as an effective countermeasure for treatment-related adverse effects to the musculoskeletal system.
Schwarz, Peter; Jørgensen, Niklas; Nielsen, Barbara
BACKGROUND: Osteoporotic fractures represent a growing economical burden to society, not only because of fractures in women, but also because of an increasing number of fractures in men. AIMS: In this cross-sectional study we aimed to investigate the association of muscular and cardio-respiratory......BACKGROUND: Osteoporotic fractures represent a growing economical burden to society, not only because of fractures in women, but also because of an increasing number of fractures in men. AIMS: In this cross-sectional study we aimed to investigate the association of muscular and cardio......-respiratory fitness with BMD at the spine and hip in men. RESULTS: The association between independent variables maximal aerobic capacity (VO(2max)), leg power and hand grip strength, and dependent variables BMD at the spine and total hip was explored in a series of linear regression models successively adjusted.......011) with BMD at total hip. CONCLUSIONS: We found that cardiorespiratory fitness was associated with BMD in men. Furthermore, hand grip strength and leg power were associated with increasing BMD at the lumbar spine and total hip in men, respectively. Further prospective studies are needed to further investigate...
Full Text Available Abstract Comparison of protein intakes on strength, body composition and hormonal changes were examined in 23 experienced collegiate strength/power athletes participating in a 12-week resistance training program. Subjects were stratified into three groups depending upon their daily consumption of protein; below recommended levels (BL; 1.0 – 1.4 g·kg-1·day-1; n = 8, recommended levels (RL; 1.6 – 1.8 g·kg-1·day-1; n = 7 and above recommended levels (AL; > 2.0 g·kg-1·day-1; n = 8. Subjects were assessed for strength [one-repetition maximum (1-RM bench press and squat] and body composition. Resting blood samples were analyzed for total testosterone, cortisol, growth hormone, and insulin-like growth factor. No differences were seen in energy intake (3,171 ± 577 kcal between the groups, and the energy intake for all groups were also below the recommended levels for strength/power athletes. No significant changes were seen in body mass, lean body mass or fat mass in any group. Significant improvements in 1-RM bench press and 1-RM squat were seen in all three groups, however no differences between the groups were observed. Subjects in AL experienced a 22% and 42% greater change in Δ 1-RM squat and Δ 1-RM bench press than subjects in RL, however these differences were not significant. No significant changes were seen in any of the resting hormonal concentrations. The results of this study do not provide support for protein intakes greater than recommended levels in collegiate strength/power athletes for body composition improvements, or alterations in resting hormonal concentrations.
Janssen, T W; van Oers, C A; Hollander, A P; Veeger, DirkJan (H. E. J.); van der Woude, L H
This study investigated in rather specific wheelchair tests the relationships among estimates of isometric upper-body strength (Fiso), sprint power (P30), aerobic power (VO2peak), and maximal power output (POaer) in a group of 44 men (age 34 +/- 12 yr) with longstanding spinal cord injuries ranging
Influência do processo de familiarização para avaliação da força muscular em testes de 1-RM Influencia del proceso de familiarizacion para evaluación de la fuerza muscular en tests de 1-RM Influence of familiarization process on muscular strength assessment in 1-RM tests
Raphael Mendes Ritti Dias
saludables con experiencia previa de por lo menos seis meses de entrenamiento con pesos, fueron sometidos a tests reptitivos de 1-RM en los ejercicios supino en banco horizontal, agachamiento y rosca directa de bíceps. Los tests fueran ejecutados en cuatro sesiones, intervaladas en cada 48-72 horas. Un número máximo de tres tentativas, con intérvalo de tres a cinco minutos para recuperación, fué utilizado en cada ejercicio, en las cuatro sessiones de testeo. ANOVA se utilizó para medidas repetidas, seguida por el test post hoc de Tukey, cuando p 0,05, bien con entre la tercera y la cuarta sesión en el supino en el banco horizontal y en el agachamiento (p > 0,05. Los resultados indican que la falta de familiarización previa con tests de 1-RM puede comprometer la evaluación de la fuerza muscular. Por lo tanto, se sugiere para la evaluación mas acurada de la fuerza muscular mediante tests de 1-RM la ejecución de dos a tres sesiones de familiarización en los hombres adultos con experiencia en ejercicios con pesos.Although the use of maximum repetition tests (1-RM is frequent for assessment of the muscular strength, one believes that the results obtained may be affected by the lack of previous familiarization, even in skilled subjects in exercises with weights. Thus, the objective of this study was to investigate the impact of the familiarization process on the muscular strength assessment in 1-RM tests. To do so, 21 men (24.5 ± 3.8 years of age, apparently healthy and with previous experience of at least six months on weight training, were submitted to repetitive tests of 1-RM in bench press, squat, and arm curl exercises. The tests were performed in four sessions with intervals every 48-72 hours. A maximum number of three attempts with 3-5 minutes interval for recovery was used in each exercise in the four testing sessions. The analysis of variance ANOVA for repeated measures followed by the post hoc Tukey test when p 0.05 as well as between the third and fourth
Li, Mian; Yao, Wenguo; Sundahl, Cynthia
It remains unclear if Gulf War (GW) veterans have a higher risk of developing motor neuron disorder. We intended to establish baseline neurophysiological values, including thenar motor unit number estimate (MUNE) and isometric hand grip (IHG) strength, to compare future follow-ups of deployed GW veterans with or without muscular complaints. We evaluated 19 GW veterans with self-reported weakness, cramps, or excessive muscle fatigue (Ill-19) and compared them with 18 controls without such muscular complaints (C-18). We performed MUNE on hand thenar muscles using adapted multipoint stimulation method for Ill-19 and 15 controls (C-15). We measured IHG strength (maximum force, endurance, and fatigue level) on Ill-19 and C-18 with a hand dynamometer. We performed nerve conduction studies on all study participants to determine which subjects had mild carpal tunnel syndrome (CTS). We compared the MUNE and IHG strength measures between Ill group and controls and between those with CTS and those without CTS. We obtained thenar MUNE of Ill-19 (95% CI of mean: 143-215; mean age: 46 yr) and compared it with that of C-15 (95% CI of mean: 161-230; mean age: 45 yr), and 95% of CI of mean among IHG strength variables (maximum force: 324-381 Newton; endurance: 32-42 s; fatigue level: 24%-33%) compared with C-18 (maximum force: 349-408 Newton; endurance: 35-46 s; fatigue level: 21%-27%). There was no significant difference in either MUNE or IHG strength between Ill-19 group and controls. The MUNE and IHG maximum forces were significantly lower in those with CTS compared with those without CTS. As a surrogate of mild CTS, the median versus ulnar distal sensory latency on nerve conduction study was only weakly associated with MUNE, maximum force, and fatigue level, respectively. To our knowledge, no published study on MUNE reference values of military veteran population has been available. The quantifiable values of both thenar MUNE and IHG strength of military veterans serve as
Joshi, N.V.; Salcedo, D.; Gil, H.
The rotational strength of optical activity has been examined as a function of power of the incident radiation in a quartz crystal for the first time. It has been observed that the angle of rotation is proportional to the square root of the intensity of the radiation. The present experimental data directly support the recently proposed model which takes into account the electronic polarizability rather than the atomic polarizability. This model explicitly explains the role of the incident power in estimating the angle of rotation
Zhang, Yue; Wang, Yi-Zhao; Huang, Li-Ping; Bai, Bei; Zhou, Shi; Yin, Miao-Miao; Zhao, Hua; Zhou, Xiao-Na; Wang, Hong-Tu
The aim of this study was to evaluate the effects of an aquatic exercise program designed to enhance muscular strength in paretic lower limbs in subacute stroke patients. Thirty-six subacute stroke patients were randomly divided to a conventional or an aquatic group (n = 18 each). Outcome measures were assessed at baseline and after 8 wks of training. For the paretic lower limbs, maximum isometric voluntary contraction strength of the rectus femoris and biceps femoris caput longus and the tibialis anterior and lateral gastrocnemius was measured. Cocontraction ratios during knee extension and flexion and ankle dorsiflexion and plantarflexion were calculated respectively. In addition, Modified Ashworth Scale, Functional Ambulation Category, and Barthel Index were assessed. Compared with the conventional intervention, the aquatic intervention resulted in significantly higher knee extension (P = 0.002) and ankle plantarflexion torque (P = 0.002), accompanied with a significantly lower knee extension cocontraction ratio in the paretic limb (P = 0.000). Functional Ambulation Category (P = 0.009) and Barthel Index (P = 0.024) were greater in aquatic group than conventional group posttreatment. Modified Ashworth Scale scores did not show any differences between groups. Aquatic exercise enhanced muscle strength in paretic lower limbs and improved muscle cocontraction without increasing spasticity in subacute stroke patients.
Greenleaf, J. E.; Starr, J. C.; Van Beaumont, W.; Convertino, V. A.
Measurements of maximal grip strength and endurance at 40 percent max strength were obtained for 7 men 19-21 years of age, 1-2 days before and on the first recovery day during three 2-week bedrest (BR) periods, each separated by a 3-week ambulatory recovery period. The subjects performed isometric exercise (IME) for 1 hr/day, isotonic exercise (ITE) for 1 hr/day, and no exercise (NOE) in the three BR periods. It was found that the mean maximal grip strength was unchanged after all three BR periods. Mean grip endurance was found to be unchanged after IME and ITE training, but was significantly reduced after NOE. These results indicate that IME and ITE training during BR do not increase or decrease maximal grip strength, alghough they prevent loss of grip endurance, while the maximal strength of all other major muscle groups decreases in proportion to the length of BR to 70 days. The maximal strength reduction of the large muscle groups was found to be about twice that of the small muscle groups during BR. In addition, it is shown that changes in maximal strength after spaceflight, BR, or water immersion deconditioning cannot be predicted from changes in submaximal or maximal oxygen uptake values.
Full Text Available Objective To determine the reliability of hand-held dynamometry (HHD for lower limb isometric muscle strength measurement in children with Duchenne and Becker muscular dystrophy (DMD/BMD. Methods A total of 21 children [20 males and one female; mean age was (7.88 ± 2.87 years, ranging between 3.96-14.09 years; mean age at diagnosis was (5.88 ± 2.88 years, ranging between 1.35-12.89 years; mean height was (120.64 ± 16.30 cm, ranging between 97-153 cm; mean body weight was (24.62 ± 9.05 kg, ranging between 14-50 kg] with DMD (19/21 and BMD (2/21 were involved from Rehabilitation Center of Children's Hospital of Fudan University. The muscle strength of hip, knee and ankle was measured by HHD under standardized test methods. The test-retest results were compared to determine the inter-test reliability, and the results among testers were compared to determine the inter-tester reliability. Results HHD showed fine inter-tester reliability (ICC = 0.762-0.978 and inter-test reliability (ICC = 0.690-0.938 in measuring lower limb muscle strength of children with DMD/BMD. Results also showed relatively poor reliability in distal muscle groups (foot plantar flexion and dorsiflexion. Conclusions HHD, showing fine inter-tester and inter-test reliability in measuring the lower limb muscle strength of children with DMD/BMD, can be used in monitoring muscle strength changing and assessing effects of clinical interventions. DOI: 10.3969/j.issn.1672-6731.2015.05.009
Behm, David G.; Young, James D.; Whitten, Joseph H. D.; Reid, Jonathan C.; Quigley, Patrick J.; Low, Jonathan; Li, Yimeng; Lima, Camila D.; Hodgson, Daniel D.; Chaouachi, Anis; Prieske, Olaf; Granacher, Urs
Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics), there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass) and power training programs (e.g., plyometric training) on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with the unilateral
David G. Behm
Full Text Available Numerous national associations and multiple reviews have documented the safety and efficacy of strength training for children and adolescents. The literature highlights the significant training-induced increases in strength associated with youth strength training. However, the effectiveness of youth strength training programs to improve power measures is not as clear. This discrepancy may be related to training and testing specificity. Most prior youth strength training programs emphasized lower intensity resistance with relatively slow movements. Since power activities typically involve higher intensity, explosive-like contractions with higher angular velocities (e.g., plyometrics, there is a conflict between the training medium and testing measures. This meta-analysis compared strength (e.g., training with resistance or body mass and power training programs (e.g., plyometric training on proxies of muscle strength, power, and speed. A systematic literature search using a Boolean Search Strategy was conducted in the electronic databases PubMed, SPORT Discus, Web of Science, and Google Scholar and revealed 652 hits. After perusal of title, abstract, and full text, 107 studies were eligible for inclusion in this systematic review and meta-analysis. The meta-analysis showed small to moderate magnitude changes for training specificity with jump measures. In other words, power training was more effective than strength training for improving youth jump height. For sprint measures, strength training was more effective than power training with youth. Furthermore, strength training exhibited consistently large magnitude changes to lower body strength measures, which contrasted with the generally trivial, small and moderate magnitude training improvements of power training upon lower body strength, sprint and jump measures, respectively. Maturity related inadequacies in eccentric strength and balance might influence the lack of training specificity with
Young, Warren B
The purposes of this review are to identify the factors that contribute to the transference of strength and power training to sports performance and to provide resistance-training guidelines. Using sprinting performance as an example, exercises involving bilateral contractions of the leg muscles resulting in vertical movement, such as squats and jump squats, have minimal transfer to performance. However, plyometric training, including unilateral exercises and horizontal movement of the whole body, elicits significant increases in sprint acceleration performance, thus highlighting the importance of movement pattern and contraction velocity specificity. Relatively large gains in power output in nonspecific movements (intramuscular coordination) can be accompanied by small changes in sprint performance. Research on neural adaptations to resistance training indicates that intermuscular coordination is an important component in achieving transfer to sports skills. Although the specificity of resistance training is important, general strength training is potentially useful for the purposes of increasing body mass, decreasing the risk of soft-tissue injuries, and developing core stability. Hypertrophy and general power exercises can enhance sports performance, but optimal transfer from training also requires a specific exercise program.
Buśko, Krzysztof; Pastuszak, Anna; Lipińska, Monika; Lipińska, Marta; Gryko, Karol
The purpose of this study was to investigate the relationship between somatotype, muscular strength, power output measured in maximal cycle ergometer exercise bouts, and maximal power output and height of rise of the body mass centre (jump height) measured in akimbo counter movement jump (ACMJ), counter movement jump (CMJ) and spike jump (SPJ), in male basketball players. Thirteen male basketball players (second division, age 19.4 ± 0.8 years, body height 192.9 ± 5.6 cm, body mass 88.8 ± 8.6 kg, training experience 9.3 ± 0.8 years) participated in the study. Somatotype was determined using the Heath-Carter method. Maximal joint torques were measured under static conditions. Power output was measured in 2 maximal cycle ergometer exercise bouts, 10 seconds each, with increasing external loads equal to 7.5 and 10.0% of the body weight (BW). All jump trials (ACMJ, CMJ and SPJ) were performed on a force plate. The mean somatotype of basketball players amounted to: 2.8-4.2-3.2. The sum of the joint torques for left and right lower extremities (0.613), trunk (0.631) and all six measured muscle groups (0.647) were significantly correlated (p jump during ACMJ, CMJ and SPJ trials. The power output measured in maximal cycle ergometer exercise bouts with increasing external loads was significantly correlated (p basketball players' anthropometric characteristics can influence their level of performance but it is not a decisive factor.
Full Text Available Michael TC Liang,1 Lorena Quezada,1 WY Jamie Lau,1 Bulent Sokmen,2 Thomas W Spalding11Department of Kinesiology and Health Promotion, California State Polytechnic University, Pomona, CA, USA; 2Department of Kinesiology, Sonoma State University, Rohnert Park, CA, USAAbstract: To examine the effect of a 10-week upper-body resistance training program on bone turnover markers and site-specific bone mineral density (BMD in the wrist and distal half of the ulna and radius in untrained and healthy young premenopausal women.Methods: Twenty-two subjects (aged 22.1 ± 1.8 years were randomly assigned to a resistance training (n = 12 or no training control (n = 10 group. The following outcome variables were measured before and after 10 weeks of resistance training: (1 bone formation biomarker osteocalcin, and bone resorption biomarker tartrate-resistant acid phosphatase isoform 5b; (2 BMD in the wrist and distal half of the ulna and radius; (3 isokinetic strength of the elbow and knee extensors and flexors; (4 dynamic strength of the arm extensors and flexors; and (5 maximum number of push-ups.Results: The 10-week upper body resistance training intervention resulted in improved strength performance in push-ups (resistance training versus control: P < 0.05, chest presses (P < 0.05, and pulldowns (P < 0.05. However, there was no improvement in the BMD of the wrist (P > 0.05, BMD of the distal half of the ulna and radius (P > 0.05, and metabolic biomarkers osteocalcin (P > 0.05 and tartrate-resistant acid phosphatase isoform 5b (P > 0.05, except for the osteocalcin/tartrate-resistant acid phosphatase isoform 5b ratio. Also, no improvement in the resistance training group was observed for isokinetic strength of the knee and elbow flexion/extension.Conclusion: Upper-body muscular strength performance, but not bone metabolic markers and BMD of the wrist, can be improved with a 10-week upper body resistance training program of the nonweight-bearing limbs in
Puolakkainen, Tero; Ma, Hongqian; Kainulainen, Heikki; Pasternack, Arja; Rantalainen, Timo; Ritvos, Olli; Heikinheimo, Kristiina; Hulmi, Juha J; Kiviranta, Riku
Inhibition of activin/myostatin pathway has emerged as a novel approach to increase muscle mass and bone strength. Duchenne muscular dystrophy (DMD) is a neuromuscular disorder that leads to progressive muscle degeneration and also high incidence of fractures. The aim of our study was to test whether inhibition of activin receptor IIB ligands with or without exercise could improve bone strength in the mdx mouse model for DMD. Thirty-two mdx mice were divided to running and non-running groups and to receive either PBS control or soluble activin type IIB-receptor (ActRIIB-Fc) once weekly for 7 weeks. Treatment of mdx mice with ActRIIB-Fc resulted in significantly increased body and muscle weights in both sedentary and exercising mice. Femoral μCT analysis showed increased bone volume and trabecular number (BV/TV +80%, Tb.N +70%, P treatment of mdx mice with the soluble ActRIIB-Fc results in a robust increase in bone mass, without any additive effect by voluntary running. Thus ActRIIB-Fc could be an attractive option in the treatment of musculoskeletal disorders.
Gettman, Larry R.; Huckel, Jack R.
The purpose of this study was to relate leg strength and power to alpine skiing success as measured by FIS points. Isometric leg strength was represented by the knee extension test described by Clarke. Leg power was measured by the vertical jump test and the Margaria-Kalamen stair run. Results in the strength and power tests were correlated with…
The purpose of this review was to determine whether past research provides conclusive evidence about the effects of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the consumption of 1.2-2.0 g protein.kg -1 of body weight, and ≥44-50 kcal.kg-1 of body weight. Researchers have tested the effects of timing of protein supplement ingestion on various physical changes in weightlifters. In general, protein supplementation pre- and post-workout increases physical performance, training session recovery, lean body mass, muscle hypertrophy, and strength. Specific gains, differ however based on protein type and amounts. Studies on timing of consumption of milk have indicated that fat-free milk post-workout was effective in promoting increases in lean body mass, strength, muscle hypertrophy and decreases in body fat. The leucine content of a protein source has an impact on protein synthesis, and affects muscle hypertrophy. Consumption of 3–4 g of leucine is needed to promote maximum protein synthesis. An ideal supplement following resistance exercise should contain whey protein that provides at least 3 g of leucine per serving. A combination of a fast-acting carbohydrate source such as maltodextrin or glucose should be consumed with the protein source, as leucine cannot modulate protein synthesis as effectively without the presence of insulin. Such a supplement post-workout would be most effective in increasing muscle protein synthesis, resulting in greater muscle hypertrophy and strength. In contrast, the consumption of essential amino acids and dextrose appears to be most effective at evoking protein synthesis prior to rather than following resistance exercise. To further enhance muscle hypertrophy and strength, a resistance weight- training program of at least 10–12 weeks with compound movements for
Full Text Available Abstract The purpose of this review was to determine whether past research provides conclusive evidence about the effects of type and timing of ingestion of specific sources of protein by those engaged in resistance weight training. Two essential, nutrition-related, tenets need to be followed by weightlifters to maximize muscle hypertrophy: the consumption of 1.2-2.0 g protein.kg -1 of body weight, and ≥44-50 kcal.kg-1 of body weight. Researchers have tested the effects of timing of protein supplement ingestion on various physical changes in weightlifters. In general, protein supplementation pre- and post-workout increases physical performance, training session recovery, lean body mass, muscle hypertrophy, and strength. Specific gains, differ however based on protein type and amounts. Studies on timing of consumption of milk have indicated that fat-free milk post-workout was effective in promoting increases in lean body mass, strength, muscle hypertrophy and decreases in body fat. The leucine content of a protein source has an impact on protein synthesis, and affects muscle hypertrophy. Consumption of 3–4 g of leucine is needed to promote maximum protein synthesis. An ideal supplement following resistance exercise should contain whey protein that provides at least 3 g of leucine per serving. A combination of a fast-acting carbohydrate source such as maltodextrin or glucose should be consumed with the protein source, as leucine cannot modulate protein synthesis as effectively without the presence of insulin. Such a supplement post-workout would be most effective in increasing muscle protein synthesis, resulting in greater muscle hypertrophy and strength. In contrast, the consumption of essential amino acids and dextrose appears to be most effective at evoking protein synthesis prior to rather than following resistance exercise. To further enhance muscle hypertrophy and strength, a resistance weight- training program of at least 10–12 weeks
Efeito de um programa de resistência muscular na capacidade funcional e na força muscular dos extensores do joelho em idosas pré-frágeis da comunidade: ensaio clínico aleatorizado do tipo crossover Impact of resistance exercise program on functional capacity and muscular strength of knee extensor in pre-frail community-dwelling older women: a randomized crossover trial
Lygia P. Lustosa
vulnerability. OBJECTIVE: The aim of this study was to verify the effect of a muscle-strengthening program with load in pre-frail elder women with regards to the functional capacity, knee extensor muscle strength and their correlation. METHODS: Thrity-two pre-frail community-dwelling women participated in this study. Potential participants with cognitive impairment (MEEM, lower extremities orthopedic surgery, fractures, inability to walk unaided, neurological diseases, acute inflammatory disease, tumor growth, regular physical activity and current use of immunomodulators were excluded. All partcipants were evaluated by a blinded assessor using: Timed up and go (TUG, 10-Meter Walk Test (10MWT and knee extensor muscle strength (Byodex System 3 Pro® isokinetic dynamometer at angular speeds of 60 and 180(0/s. The intervention consisted of strengthening exercises of the lower extremities at 70% of 1RM, three times/ week for ten weeks. The statistical analysis was performed using the ANOVA and Spearman tests RESULTS: After the intervention, it was observed statistical significance on the work at 180(0/s (F=12.71, p=0.02, on the power at 180(0/s (F=15.40, p=0.02 and on the functional capacity (TUG, F=9.54, p=0.01; TC10, F=3.80, p=0.01. There was a good negative and statistically significant correlation between the TUG and work at 60(0/s, such as the TUG and work at 180(0/s (r=-0.65, p=0.01; r=-0.72, p=0.01. CONCLUSION: The intervention improved the muscular power and the functional capacity. The increase of the power correlated with function, which is an important variable of the quality of life in the pre-frail elders. Article registered in the ISRCT register under number ISRCTN62824599.
Jonathan H. Soslow
Full Text Available Duchenne muscular dystrophy (DMD is an X-linked disorder that leads to cardiac and skeletal myopathy. The complex immune activation in boys with DMD is incompletely understood. To better understand the contribution of the immune system into the progression of DMD, we performed a systematic characterization of immune cell subpopulations obtained from peripheral blood of DMD subjects and control donors. We found that the number of CD8 cells expressing CD26 (also known as adenosine deaminase complexing protein 2 was increased in DMD subjects compared to control. No differences, however, were found in the levels of circulating factors associated with pro-inflammatory activation of CD8/CD26 cells, such as tumor necrosis factor-α (TNFα, granzyme B, and interferon-γ (IFNγ. The number of CD8/CD26 cells correlated directly with quantitative muscle testing (QMT in DMD subjects. Since CD26 mediates binding of adenosine deaminase (ADA to the T cell surface, we tested ADA-binding capacity of CD8/CD26 cells and the activity of bound ADA. We found that mononuclear cells (MNC obtained from DMD subjects with an increased number of CD8/CD26 T cells had a greater capacity to bind ADA. In addition, these MNC demonstrated increased hydrolytic deamination of adenosine to inosine. Altogether, our data demonstrated that (1 an increased number of circulating CD8/CD26 T cells is associated with preservation of muscle strength in DMD subjects, and (2 CD8/CD26 T cells from DMD subjects mediated degradation of adenosine by adenosine deaminase. These results support a role for T cells in slowing the decline in skeletal muscle function, and a need for further investigation into contribution of CD8/CD26 T cells in the regulation of chronic inflammation associated with DMD.
Interpretação dos mecanismos de gradação da força muscular através da acelerometria Interpretacion de los mecanismos de graduación de la fuerza muscular a través de la acelerometria Interpretation of the mechanisms related to the muscular strength gradation through accelerometry
Thiago Torres da Matta
ía (señal de MMG. Estos parámetros fueron analizados en las direcciones X (perpendicular a las fibras e Y (paralela a las fibras. Ambos grupos presentaron un comportamiento decreciente de la FME (Y con una carga, siendo mas pronunciado para el grupo femenino. La variáble FME (X, en el grupo femenino, presentó um comportamiento semejante a la FME (Y, siendo apenas observada diferencia estadísticamente significativa entre 20% de la CM y todas las demas cargas (p = 0,0022 para 40% y p The aim of this study was to characterize the temporal and spectral components of the muscle contractions in different contraction levels through the accelerometry. Fifteen male and twelve female right-handed individuals participated in this study. The trial was constituted by a maximal workload (MW test that allowed to determine five different workloads (20%, 40%, 60%, 80% and 100% of MW which, by its turn, allowed to determine five percentage workloads during the strength test (20%, 40%, 60%, 80%, and 100% of the MW in isometry during eight seconds each of them. A biaxial accelerometer was put on the muscular abdomen of the right brachii biceps muscle. The mean square root (RMS value, a temporal parameter, and the mean frequency (MFE, a spectral parameter were extracted from the accelerometry signals (MMG signals. Such parameters were analyzed towards the X (perpendicular to the fibers and Y (parallel to the fibers directions. Both groups presented a descent behavior pattern of the loaded MFE (Y, and the most accentuated was the female group. The MFE variable (X in the female group presented similar behavior before the MFE (Y, and it was observed a statistically significant difference only between 20% of the MW and every other workload (p = 0.0022 for 40% and p < 0.0001 for the remaining. The male group did not present any statistically significant difference between workloads. The RMS value (Y presented an ascent behavior with the workload in both genders, presenting differences
Reprodutibilidade inter e intradias do Power Control em um teste de potência muscular Reproducibilidad inter e intradías de Power Control en un test de potencia muscular Inter and intradays reproducibility of Power Control in test of muscle power
Fabrício Miranda Ribeiro
la comparación de los resultados de PM para carga individualizada, y post-hoc de Bonferroni para especificar cuáles medidas diferían entre sí, con nivel de significancia de 5%. No fueron encontradas diferencias significativas entre las medidas inter e intradías respectivamente en remo (p = 0,991; p = 1,000 y tirón abierto por delante en pulley alto (p = 0,607; p = 1,000. Podemos verificar que, para un simple test de PM, Power Control TechnoGym@ se presenta como un instrumento útil y fidedigno en la utilización de cargas en PM.The aim of this study was to determine the reproducibility of an instrument of measurement of muscular power (MP, the Power Control Technogym@, through a simple test of MP. Fifteen women (26.2 ± 1.9 years experienced in strength training in two exercises - the low row and the front lat pull down, were evaluated through a test of 1RM. The maximum load and the load that generated the MP in each exercise were determined. After obtaining the load that generated the MP, the individuals carried out three days of testing with the purpose to analyze inter and intradays reproducibility of the generated power. The comparison between the results of the MP was made through the ANOVA for repeated measures and Bonferroni post-hoc to specify which measures differ from each other, being adopted a level of significance of 5%. No significant differences were found at inter and intradays measurements respectively in the low row (p = 0.991; p = 1.000 and front lat pull down (p = 0.607; p = 1.000. This data can suggest that, for a simple test of MP, the Power Control TechnoGym@ seems to be a useful and trustworthy instrument in the use of loads in the MP.
... sets of muscles and cause different degrees of muscle weakness. Duchenne muscular dystrophy is the most common and the most severe ... can walk independently. Prednisone If a child has Duchenne muscular ... to help slow the rate of muscle deterioration. By doing so, the child may be ...
Radaelli, Regis; Fleck, Steven J; Leite, Thalita; Leite, Richard D; Pinto, Ronei S; Fernandes, Liliam; Simão, Roberto
The study's purpose was to compare the response of performing 1, 3, and 5 sets on measures of performance and muscle hypertrophy. Forty-eight men, with no weight training experience, were randomly assigned to one of the 3 training groups, 1 SET, 3 SETS, 5 SETS, or control group. All training groups performed 3 resistance training sessions per week for 6 months. The 5 repetition maximum (RM) for all training groups increased in the bench press (BP), front lat pull down (LPD), shoulder press (SP), and leg press (LP) (p ≤ 0.05), with the 5 RM increases in the BP and LPD being significantly greater for 5 SETS compared with the other training groups (p ≤ 0.05). Bench press 20 RM in the 3-SET and 5-SET groups significantly increased with the increase being significantly greater than the 1-SET group and the 5-SET group increase being significantly greater than the 3-SET group (p ≤ 0.05). LP 20 RM increased in all training groups (p ≤ 0.05), with the 5-SETS group showing a significantly greater increase than the 1-SET group (p ≤ 0.05). The 3-SET and 5-SET groups significantly increased elbow flexor muscle thickness (MT) with the 5-SET increase being significantly greater than the other 2 training groups (p ≤ 0.05). The 5-SET group significantly increased elbow extensor MT with the increase being significantly greater than the other training groups (p ≤ 0.05). All training groups decreased percent body fat, increased fat-free mass, and vertical jump ability (p ≤ 0.05), with no differences between groups. The results demonstrate a dose-response for the number of sets per exercise and a superiority of multiple sets compared with a single set per exercise for strength gains, muscle endurance, and upper arm muscle hypertrophy.
Full Text Available Purpose: determination of abnormalities and disorders of muscular skeletal apparatuses’ status of power lifters, who have vertebral abnormalities of backbone. Material: 58 junior sportsmen participated in the research. 36 sportsmen were the main group of the research and had vertebral disorders in backbone. For posture testing visual examination was used. Backbone mobility was tested with goniometry method. Flat feet were registered with plantography method. Results: we determined posture abnormalities in sagittal and frontal planes; feet flat, limited maximal movements in thoracic and lumbar spines. It was determined that the most limited were rotational movements and backbone unbending. The next were side bents. These limitations were accompanied by pain syndrome. These observations indirectly confirmed theory of direct interaction of backbone structures with nervous structures. It is also a confirmation of vertebral abnormalities’ presence in junior sportsmen. Conclusions: it was found that in junior sportsmen - power lifters with backbone pathologies in 100% of cases symptoms are determined by local limitations of backbone mobility with pain syndrome. In 35% of cases they are accompanied by posture’s disorders and feet flat. Orientation and methodic of rehabilitation of such sportsmen have been determined.
Hammami, Raouf; Chaouachi, Anis; Makhlouf, Issam; Granacher, Urs; Behm, David G
Balance, strength and power relationships may contain important information at various maturational stages to determine training priorities. The objective was to examine maturity-specific relationships of static/dynamic balance with strength and power measures in young male athletes. Soccer players (N = 130) aged 10-16 were assessed with the Stork and Y balance (YBT) tests. Strength/power measures included back extensor muscle strength, standing long jump (SLJ), countermovement jump (CMJ), and 3-hop jump tests. Associations between balance with strength/power variables were calculated according to peak-height-velocity (PHV). There were significant medium-large sized correlations between all balance measures with back extensor strength (r = .486-.791) and large associations with power (r = .511-.827). These correlation coefficients were significantly different between pre-PHV and circa PHV as well as pre-PHV and post-PHV with larger associations in the more mature groups. Irrespective of maturity-status, SLJ was the best strength/power predictor with the highest proportion of variance (12-47%) for balance (i.e., Stork eyes opened) and the YBT was the best balance predictor with the highest proportion of variance (43-78%) for all strength/power variables. The associations between balance and muscle strength/power measures in youth athletes that increase with maturity may imply transfer effects from balance to strength/power training and vice versa in youth athletes.
Buckon, Cathleen; Sienko, Susan; Bagley, Anita; Sison-Williamson, Mitell; Fowler, Eileen; Staudt, Loretta; Heberer, Kent; McDonald, Craig M; Sussman, Michael
In the absence of a curative treatment for Duchenne Muscular Dystrophy (DMD), corticosteroid therapy (prednisone, deflazacort) has been adopted as the standard of care, as it slows the progression of muscle weakness and enables longer retention of functional mobility. The ongoing development of novel pharmacological agents that target the genetic defect underlying DMD offer hope for a significant alteration in disease progression; however, substantiation of therapeutic efficacy has proved challenging. Identifying functional outcomes sensitive to the early, subtle changes in muscle function has confounded clinical trials. Additionally, the alterations in disease progression secondary to corticosteroid therapy are not well described making it difficult to ascertain the benefits of novel agents, often taken concurrently with corticosteroids. The purpose of this study was to examine outcome responsiveness to corticosteroid therapy and age at the onset of a natural history study of ambulatory boys with DMD. Eighty-five ambulatory boys with DMD (mean age 93 mo, range 49 to 180 mo) were recruited into this study. Fifty participants were on corticosteroid therapy, while 33 were corticosteroid naïve at the baseline assessment. Within each treatment group boys were divided in two age groups, 4 to 7 years and 8 and greater years of age. The Biodex System 3 Pro isokinetic dynamometer was used to assess muscle strength. Motor skills were assessed using the upper two dimensions (standing/walking, running & jumping) of the Gross Motor Function Measure (GMFM 88) and Timed Motor Tests (TMTs) (10-meter run, sit to stand, supine to stand, climb 4-stairs). Two way analysis of variance and Pearson correlations were used for analysis. A main effect for age was seen in select lower extremity muscle groups (hip flexors, knee extensors and ankle dorsiflexors), standing dimension skills, and all TMTs with significantly greater weakness and loss of motor skill ability seen in the older age
González-Ravé, José M.; Juárez, Daniel; Rubio-Arias, Jacobo A.; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier
Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players. PMID:25114749
González-Ravé, José M; Juárez, Daniel; Rubio-Arias, Jacobo A; Clemente-Suarez, Vicente J; Martinez-Valencia, María A; Abian-Vicen, Javier
Isokinetic strength evaluation of the knee flexion and extension in concentric mode of contraction is an important part of the comprehensive evaluation of athletes. The aims of this study were to evaluate the isokinetic knee peak torque in both the extension and flexion movement in the dominant and non-dominant leg, and the relationship with jumping performance. Twelve elite male handball players from the top Spanish handball division voluntary participated in the study (age 27.68 ± 4.12 years; body mass 92.89 ± 12.34 kg; body height 1.90 ± 0.05 m). The knee extensor and flexor muscle peak torque of each leg were concentrically measured at 60º/s and 180º/s with an isokinetic dynamometer. The Squat Jump and Countermovement Jump were performed on a force platform to determine power and vertical jump height. Non-significant differences were observed between legs in the isokinetic knee extension (dominant= 2.91 ± 0.53 Nm/kg vs non-dominant = 2.70 ± 0.47 Nm/kg at 60º/s; dominant = 1.90 ± 0.31 Nm/kg vs non-dominant = 1.83 ± 0.29 Nm/kg at 180º/s) and flexion peak torques (dominant = 1.76 ± 0.29 Nm/kg vs non-dominant = 1.72 ± 0.39 Nm/kg at 60º/s; dominant = 1.30 ± 0.23 Nm/kg vs non-dominant = 1.27 ± 0.35 Nm/kg at 180º/s). Low and non-significant correlation coefficients were found between the isokinetic peak torques and vertical jumping performance (SJ = 31.21 ± 4.32 cm; CMJ = 35.89 ± 4.20 cm). Similar isokinetic strength was observed between the legs; therefore, no relationship was found between the isokinetic knee flexion and extension peak torques as well as vertical jumping performance in elite handball players.
... Surveillance Tracking and Research Network , known as MD STAR net . Learn more about CDC’s other muscular dystrophy ... for Disease Control and Prevention Email Recommend Tweet YouTube Instagram Listen Watch RSS ABOUT About CDC Jobs ...
O'Connor, Donna M; Crowe, Melissa J
This study investigated the effects of 6 weeks of dietary supplementation of beta-hydroxy-beta-methylbutyrate (HMB) and HMB combined with creatine monohydrate (HMBCr) on the muscular strength and endurance, leg power, and anthropometry of elite male rugby league players. The subjects were divided into a control group (n = 8), a HMB group (n = 11; 3 g.d(-1)) or a HMBCr group (n = 11; 12 g.d(-1) with 3 g HMB, 3 g Cr, 6 g carbohydrates). Three repetition maximum lifts on bench press, deadlifts, prone row, and shoulder press, maximum chin-up repetitions, 10-second maximal cycle test, body mass, girths, and sum of skinfolds were assessed pre- and postsupplementation. Statistical analysis revealed no effect of HMB or HMBCr on any parameter compared with presupplementation measures or the control group. HMB and HMBCr were concluded to have no ergogenic effect on muscular strength and endurance, leg power, or anthropometry when taken orally by highly trained male athletes over 6 weeks.
陈琼; 沈思云; 夏凌; 李交杰; 陈小萍; 陈晓健; 徐建华
recorded in the 1st,3rd,6th and 9th time training. Results ①The mean of peak muscle strength and the mean of peak impulse in 10 seconds of the extension and flexion directions of the neck muscles of the transporter pilots group, were obviously lower than that of the other pilot groups ( P < 0.05 ). ②The mean of peak muscle strength and the mean of peak impulse in 10 seconds of all the directions of the neck muscles of all military pilots in the 3rd,6th and 9th time training,were significantly higher than that in the 1st time training. After 3 weeks'training, the relative increment of the mean of peak muscle strength of the four mentioned directions of the neck muscles were 47.4% ,42. 6% ,65. 2% and 55. 5% respectively,while the relative increment of the mean of peak impulse in 10 seconds were 51. 6% ,41.8% ,63. 3% and 53.9% respectively. Conclusion Neck muscular strength in the flexion and extension directions of the transporter pilots group were relatively weaker than that of the other 4 pilots groups. CME-1 Neck Muscle Training Machine is effective and safe to improve neck muscular strength of military pilots.
Força muscular de atletas de voleibol de 9 a 18 anos através da dinamometria computadorizada Fuerza muscular de atletas de voleibol de 9 a 18 años a través de la dinamometria computarizada Muscular strength of 9-18-year old volleyball athletes through computational dynamometry
Full Text Available O objetivo deste estudo foi descrever e comparar as forças musculares isométrica e isocinética em diferentes graus maturacionais de meninos e meninas atletas de voleibol. Participou do estudo um total de 66 crianças e adolescentes saudáveis, em treinamento esportivo competitivo. Dos 37 meninos, 10 eram pré-púberes (PP, 15 púberes (PU e 12 pós-púberes (PO. Das 29 meninas, 11 eram PP, 13 PU e 5 PO. Foi utilizado um dinamômetro computadorizado (Cybex Norm para medir a força isocinética de flexão do cotovelo (FC e de extensão de joelho (EJ nas velocidades de 60 e 90º.s-1. A força isométrica foi medida nos mesmos exercícios nos ângulos de 60 e 90º (FC, e 45 e 60º (EJ. Utilizou-se a ANOVA para comparações entre os gêneros e graus maturacionais, e o teste post hoc de Tuckey. O nível de significância considerado foi de p El objetivo de este estudio fué describir y comparar las fuerzas musculares isométrica e isocinética en diferentes grados maduracionales de niños y niñas atletas de voleibol. Participó del estudio un total de 66 niños y adolescentes, en tratamiento deportivo competitivo. De los 37 niños, 10 eran pre-púberes (PP, 15 púberes (PU y 12 post-púberes (PO. De las 29 niñas, 11 eran PP, 13 PU e 5 PO. Fué utilizado un dinamómetro computarizado (Cybex Norm para medir la fuerza isocinética de flexión de codo (FC y extensión de rodilla (EJ en las velocidades de 60 y 90º.s-1. La fuerza isométrica fue medida en los mismos ejercicios en los ángulos de 60 y 90º (FC, y 45 y 60º (EJ. Se utilizó la ANOVA para comparaciones entre los géneros y grados maduracionales y el test post hoc de Tuckey. El nivel de significancia considerado fue de p The objective of this work was to describe and to compare the isometric and isokinetic muscular strength at different maturational degree of boys and girls volleyball athletes. 66 healthy children and youth participated in the study in a competitive sportive training
Full Text Available Athletes are constantly searching for something that will give them a competitive edge. Performance jewelry is one of the latest products on the market designed to improve athletic performance. The most common claims are that wearing this performance jewelry will improve flexibility, balance, and strength. There is considerable marketing of these products, including testimonial evidence by high profile athletes, in support of the purported benefits. In demonstrations designed to validate the performance enhancing benefits of these products, however, companies typically conduct the testing in the following sequence: The first trial is done without the bracelet on and the second trial is performed with the bracelet on. Invariably, subjects perform better on the second trial. This brings into questions whether the improvement on the second trial is due to 1 a benefit of the bracelet, 2 the fact the subjects were warmed-up (Maud et al., 2006a; 2006b, 3 subjects being habituated to the task (Benson and Friedman, 1996; Wright et al., 2009, or 4 a placebo effect (Beedie and Foad, 2009.One of the most popular performance enhancing bracelets currently on the market is sold by Power Balance® (www.powerbalance.com. The Power Balance® bracelet has two dime-sized holograms; one on either side of the bracelet. The holograms within the Power Balance® bracelet are designed to "resonate with and respond to the natural energy field of the body". This purportedly improves flexibility, balance, and strength. To our knowledge, no randomized, double- blind, placebo trials have ever been conducted evaluating the validity of these claims. Thus, the purpose of this study was to evaluate whether wearing of the Power Balance® bracelet can improve trunk flexibility, balance, strength, and lower body power.Forty-two NCAA Division III athletes (22M: 20.1 ± 1.4 years, 1.82 ± 6.4 m, 82.0 ± 12.6 kg; 20F: 19.5 ± 1.3 years, 1.66 ± 6. 8 m, 63.2 ± 8.1 kg completed four
Newton, Robert U.; Hakkinen, Keijo; Hakkinen, Arja; McCormick, Matt; Volek, Jeff; Kraemer, William J.
Examined the effects of a 10-week, mixed-methods resistance training program on young and older men. Although results confirmed some age-related reductions in muscle strength and power, the older men demonstrated similar capacity to the younger men for increases in muscle strength and power via an appropriate, periodized resistance training…
Hellen C. G. Nabuco
Full Text Available Aging is associated with sarcopenia and dynapenia, with both processes contributing to functional dependence and mortality in older adults. Resistance training (RT and increased protein intake are strategies that may contribute to health improvements in older adults. Therefore, the aim was to investigate the effects of whey protein (WP supplementation consumed either immediately pre- or post-RT on skeletal muscle mass (SMM, muscular strength, and functional capacity in pre-conditioned older women. Seventy older women participated in this investigation and were randomly assigned to one of three groups: whey protein pre-RT and placebo post-RT (WP-PLA, n = 24, placebo pre-RT and whey protein post-RT (PLA-WP, n = 23, and placebo pre- and post-RT (PLA-PLA, n = 23. Each group ingested 35 g of WP or PLA. The RT program was carried out over 12 weeks (three times per week; 3 × 8–12 repetition maximum. Body composition, muscular strength, functional capacity, and dietary intake were assessed pre- and post-intervention. Two-way analysis of covariance (ANCOVA for repeated measures, with baseline scores as covariates were used for data analysis. A time vs. group interaction (p < 0.05 was observed with WP-PLA and PLA-WP presenting greater increases compared with PLA-PLA for SMM (WP-PLA = 3.4%; PLA-WP = 4.2%; PLA-PLA = 2.0%, strength (WP-PLA = 8.1%; PLA-WP = 8.3%; PLA-PLA = 7.0%, and the 10-m walk test (WP-PLA = −10.8%; PLA-WP = −11.8%; PLA-PLA = −4.3%. Whey protein supplementation was effective in promoting increases in SMM, muscular strength, and functional capacity in pre-conditioned older women, regardless of supplementation timing. This trial was registered at ClinicalTrials.gov: NCT03247192.
Bugaj, N.V.; Lebedev, A.A.; Sharko, A.V.
Ultrasonic control which is a constituent part of a complex control system which includes specimen-free (by hardness) tests, random breaking tests and acoustic measurements is stUdied for its reliability with respect to strength properties of power-equipment metal. Quantitative and alternative criteria are developed to estimate quality of elements for power-equipment according to results of metal strength properties. Acoustic control results are presented for ultimate strength in 12Kh1MF-steel
David C. Archer
Full Text Available Background: The use of chains in resistance training is a way to accommodate the muscular strength curve. Short-term training and jump squats have been shown to increase back squat strength, but not in conjunction with each other or with chains. Jump squats have also been used to increase jump height and power. Objectives: The purpose of this study was to investigate the effects of short-term jump squat training with and without chains on strength and power. Methods: Thirty-one resistance-trained men volunteered to participate (age = 23.87 ± 2.2 years, height=174.87 ± 6.94 cm, mass = 82.74 ± 14.95 kg and were randomly assigned to one of three groups [control (C = 10, no chains (NC =10, or chains (CH = 11]. Participants had their jump height (VJ and back squat strength (BS tested before and after a week of training. The NC and CH groups performed three training sessions consisting of five sets of three reps of jump squats at 30% 1RM with 30s rest between sets. The CH group had 20% of their load added by chains when standing erect. The C group did not train. Results: A 3 (group: CH, NC, C x 2 (time: pre, post mixed factor ANOVA revealed a significant (p = 0.006 interaction for back squat 1RM. Both the CH (pre 142.56 ± 20.40 kg; post 145.66 ± 19.59 kg and NC (pre 150.00 ± 15.23 kg; post 154.77 ± 15.09 kg groups significantly increased while the C (pre 157.27 ± 25.35 kg; post 156.36 ± 24.85 kg group showed no difference. There were no significant interactions (p =0.32 or main effects for VJ (C = pre 50.59 ± 9.39cm; post 51.29 ± 9.68cm; NC = pre 55.29 ± 5.23cm; post 57.39 ± 5.22cm; CH = pre 46.19 ± 5.02; post 47.45 ± 4.62. Conclusions: The CH group was able to increase strength while lifting less overall weight. Coaches may use short-term training with chains to yield a similar increase in back squat strength as without chains. Keywords: variable resistance, back squats, novel, vertical jump
Based on the literature, the design of high-strength concrete structures and the suitability of high-strength concrete for the power plant structures have been studied. Concerning the behavior of structures, a basic difference between the high-strength concrete and the traditional one is that the ductility of the high-strength concrete is smaller. In the design, the non-linear stress-strain relationship of the high-strength concrete has to be taken into account. The use of the high-strength concrete is economical if the strength of the material can be utilized. In the long term, the good durability and wear resistance of the high-strength concrete increases the economy of the material. Because of the low permeability of the high-strength concrete, it is a potential material in the safety-related structures of nuclear power plants. The study discovered no particular power plant structure which would always be economical to design of high-strength concrete. However, the high-strength concrete was found to be a competitive material in general
Sveen, Marie-Louise; Andersen, Søren P; Ingelsrud, Lina H
In this study we investigated the effect of strength training in patients with limb-girdle muscular dystrophy (LGMD) and Becker muscular dystrophy (BMD).......In this study we investigated the effect of strength training in patients with limb-girdle muscular dystrophy (LGMD) and Becker muscular dystrophy (BMD)....
Marcos de Amorim Aquino
Full Text Available OBJECTIVE: To assess knee flexor-extensor muscular strength in elderly women with no previous history of musculoskeletal disorders on the lower limbs using an isokinetic dynamometer, in order to obtain data that could be used as a comparative parameter in the evaluation of elderly women with knee disorders, thus facilitating a better rehabilitation of these patients. METHODS: Twenty-six volunteers aged 75 to 83 years were studied using a Cybex® 6000 isokinetic dynamometer. The chosen angular velocity was 60 º/s, and concentric exercise was used for either flexion or extension. The studied parameters were: peak torque, angle of peak torque, and flexor-extensor torque rate. RESULTS: There were no differences between dominant (D and nondominant (ND knee peak torque values. This was true for both flexor (D = 42.46 ± 9.09 Nm / ND = 40.65 ± 9.38 Nm and extensor (D = 76.92 ± 13.97 Nm / ND = 77.65 ± 15.21 Nm movements. The descriptive statistical analysis of the values obtained for the flexor-extensor peak torque rate and for the angle of occurrence of peak torque was the same for the dominant and nondominant sides. CONCLUSIONS: The values of peak torque for the contralateral side can be used as a reference during rehabilitation of elderly women with acute disease of the knee, and the angular velocity of 60 º/s is proper and safe for isokinetic assessment of elderly people.OBJETIVO: Avaliar, isocineticamente, o torque dos músculos flexores e extensores dos joelhos de mulheres idosas sem afecções do sistema músculo-esquelético em membros inferiores, obtendo dados que possam servir como parâmetro de comparação na avaliação de mulheres idosas portadoras de afecções nos joelhos, colaborando para uma melhor reabilitação dessas pacientes. CASUÍSTICA E MÉTODOS: Vinte e seis voluntárias foram avaliadas. O estudo foi realizado através de um dinamômetro isocinético marca CYBEXâ modelo 6000 na velocidade angular de 60º/s. O tipo do
Full Text Available The purpose of the study was to examine the adaptive changes in myosin heavy chain (MHC and light chain (MLC isoforms in human vastus lateralis muscle caused by long-term strength and power training (54 weeks, approximately 3 times a week in untrained middle- aged men (16 in the training and 6 in the control group. Muscular MHC and MLC isoforms were determined by means of SDS-PAGE gel electrophoresis. During the training period, maximal anaerobic cycling power increased by 64 W (p < 0.001 and the maximal jumping height by 1.5 cm (p < 0. 05 in the training group, but no significant changes were found in the control group. However, the group by time effect was not significant. In the training group, the increase of the maximal jumping height correlated with the number of strength and power training sessions (r = 0.56; p < 0.05. The change of the proportion of MHC IIa isoform from 52.6 ± 12.2% to 59.4 ± 11.6% did not reach statistical significance (p = 0.070 for group by time; within training group p = 0.061 and neither did the change of the proportion of MHC IIx isoform from 18.1 ± 11.4% to 11.1 ± 9.1% (p = 0.104 for group by time; within training group p=0.032. The degree of change of MHC IIx isoform correlated with the amount of earlier recreational sports activity (r = 0.61; p < 0.05. In the training group, the changes of MLC1s isoform correlated negatively with the changes of MLC1f isoform (r = -0. 79; p < 0.05 as well as with the changes in maximal anaerobic cycling power (r = -0.81; p < 0.05, and positively with those of MHC I isoform (r = 0.81; p < 0.05. In conclusion, the long- term strength and power training ~3 times a week seemed to have only slight effects on fast MHC isoforms in the vastus lateralis muscle of untrained middle-aged men; the proportion of MHC IIa tended to increase and that of MHC IIx tended to decrease. No changes in MLC isoform profile could be shown
Full Text Available OBJETIVO: Avaliar o efeito da isquemia induzida sobre os parâmetros do sinal eletromiográfico e a força do grupo muscular extensor do punho (GMEP em mulheres saudáveis. MÉTODOS: Participaram 13 voluntárias, destras, sedentárias, com idade de 23,38±2,32 anos e índice de massa corporal (IMC de 20,68±1,87kg/m². Para determinar a força do GMEP, foram realizadas 3 contrações isométricas voluntárias máximas (CIVM, utilizando-se uma célula de carga por 15 segundos, com intervalos de 2 minutos entre cada contração, sendo todo procedimento repetido por 3 dias não consecutivos. A isquemia foi realizada por 5 minutos, utilizando um esfigmomanômetro posicionado no braço dominante e inflado até a ausência do fluxo sanguíneo, confirmada pelo ultrassom Doppler. Para coleta do sinal eletromiográfico do GMEP, utilizou-se o equipamento EMG1000 (Lynx® com eletrodo de superfície diferencial (Lynx®. Foram coletadas 3 CIVM por 15 segundos, com intervalo de 30 segundos entre elas, nas situações de pré-isquemia; isquemia; pós-isquemia imediata (pós-1 e pós-isquemia tardia (pós-2 - após 10 minutos do início da isquemia. Para análise dos parâmetros do sinal eletromiográfico, root mean square (RMS, e frequência mediana do espectro de potência do sinal foi utilizado o software MATLAB 6.5.1. Para análise estatística, foram utilizados os testes de Friedman e ANOVA two-way. RESULTADOS: A isquemia promoveu redução significativa (pOBJECTIVE: To analyze the effect of induced ischemia on the parameters of electromyographic signals and the strength of the wrist extensor muscle group (WEMG in healthy women. METHODS: Thirteen right-handed sedentary subjects aged 23.38±2.32 years old, with body mass index (BMI of 20.68±1.87kg/m², took part. To determine WEMG strength, three maximal voluntary isometric contractions (MVIC were performed using a load cell for 15 seconds, with 2 minutes intervals between contractions. The entire
A cytochemical study of histones in the muscular cells of Triturus cristatus limbs in normal regeneration of limbs irradiated by X-rays, of irradiated limbs in which the regenerative power is restored by cartilage implants
The muscular cells of regenerating limbs and of limbs in which regenerative power is restored, show an important decrease in the amount of cytophotometrically detected histones. This decrease is owing to the arginine rich fraction and to the lysine rich fraction. The muscular cells of irradiated limbs show a decrease in the amount of histones. This decrease is owing only to the arginine rich fraction and continues after the thirtieth day of irradiation and amputation [fr
Forte, Roberta; Boreham, Colin A G; De Vito, Giuseppe; Ditroilo, Massimiliano; Pesce, Caterina
Age-related reductions in strength and power are considered to negatively impact balance control, but the existence of a direct association is still an issue of debate. This is possibly due to the fact that balance assessment is complex, reflects different underlying physiologic mechanisms and involves quantitative measurements of postural sway or timing of performance during balance tasks. The present study evaluated the moderator effect of static postural control on the association of power and strength with dynamic balance tasks. Fifty-seven healthy 65-75 year old individuals performed tests of dynamic functional balance (walking speed under different conditions) and of strength, power and static postural control. Dynamic balance performance (walking speed) was associated with lower limb strength and power, as well as postural control under conditions requiring postural adjustments (narrow surface walking r(2) = 0.31, p balance tasks. Practical implications for assessment and training are discussed.
management of the disease. Manual muscle testing (MMT) is performed as part of a routine neurological exam. Manual muscle testing (MMT) was found to be...dynamometry in spinal muscular atrophy. Muscle Nerve. 2002;26(1):64-70. Mostert & Kesselring. Effects of a short-term exercise training program on aerobic...dictated by the diseased motor neuron. The surviving muscles have more viable hypertrophied type 1 motor units possibly resulting in a lower MPF. Our
Rugby union requires high levels of strength and power in order to support the physical requirements of the game. The competitive structure of rugby union in the English premiership places limitations on the time available for players’ physical development. The aim of this thesis was to analyse the scope and magnitude of strength and power adaptation potential, whilst identifying effective training strategies to support physical development in professional rugby union players. Chapter 3 monit...
Tiggemann, Carlos Leandro; Dias, Caroline Pieta; Radaelli, Regis; Massa, Jéssica Cassales; Bortoluzzi, Rafael; Schoenell, Maira Cristina Wolf; Noll, Matias; Alberton, Cristine Lima; Kruel, Luiz Fernando Martins
The present study compared the effects of 12 weeks of traditional resistance training and power training using rated perceived exertion (RPE) to determine training intensity on improvements in strength, muscle power, and ability to perform functional task in older women. Thirty healthy elderly women (60-75 years) were randomly assigned to traditional resistance training group (TRT; n = 15) or power training group (PT; n = 15). Participants trained twice a week for 12 weeks using six exercises. The training protocol was designed to ascertain that participants exercised at an RPE of 13-18 (on a 6-20 scale). Maximal dynamic strength, muscle power, and functional performance of lower limb muscles were assessed. Maximal dynamic strength muscle strength leg press (≈58 %) and knee extension (≈20 %) increased significantly (p training. Muscle power also increased with training (≈27 %; p functional performance after training period (≈13 %; p effective in improving maximal strength, muscle power, and functional performance of lower limbs in elderly women.
Avaliação antropométrica e da força muscular em nadadores pré-púberes e púberes Evaluacion antropometrica y de fuerza muscular en nadadores pre-púberes y púberes Anthropometric and muscle strength evaluation in prepubescent and pubescent swimmer boys and girls
estos, 11 chicos eran pre-púberes (PP y 16 púberes (PU y 8 chicas eran PP y 13 PU. Los datos estudiados fueron peso corporal estatura, pliegues cutáneos y circunferencias. Un dinamómetro computarizado (Cybex Norm fué utilizado para medir las fuerzas isocinética (60 e 90º.s-1 e isométrica (45 e 60º de extención de rodilla (EJ e isocinética (60 e 90º.s-1 e isométrica (60 e 90º de flexión de codo (FC. Para tal efecto, el pico de cambio fue utilizado. No hubo diferencia en la fuerza muscular entre los chicos y las chicas PP. En el grupo PU, los chicos fueron más fuertes que las chicas en todos los tests de EJ y FC, siendo que esa diferencia persistió en casi todos los tests cuando corregido por el peso corporal (excepto los tests de EJ isométricos, donde las chicas PU y PP no se dieferenciaron. Estos resultados muestran un padrón de fuerza muscular en niños y adolescentes nadadores.Anthropometric and muscle strength evaluation in prepubescent and pubescent swimmers and muscle strength and body composition are important for a better sporting performance. The objective of this study was to describe and to compare anthropometrical and muscle strength aspects of prepubescent and pubescent swimmer boys and girls. Forty-eight healthy competitive swimmers participated in this study. Among them, 11 boys were prepubescent (PP and 16 were pubescent (PU and 8 girls were PP and 13 PU. The anthropometrical data studied were body weight, stature, skinfolds and circumferences. A computerized dynamometer (Cybex Norm was used to isokinetic (60 and 90º.s-1 and isometric strength measurements (45 and 60º of knee extension (KE and isokinetic (60 and 90º.s-1 and isometric (60 and 90º strength of elbow flexion (EF. There were no differences between PP boys and girls in muscle strength. In PU group, the boys were stronger than girls in all KE and EF tests. This difference was shown in almost all tests when adjusted by body weight (except in KE isometric tests, where values
In the mid-sixties, Gary Graham, a Boeing designer, developed a cardiovascular conditioner for a planned Air Force orbiting laboratory. After the project was cancelled, Graham participated in space station conditioning studies for the Skylab program. Twenty years later, he used this expertise to develop the Shuttle 2000-1, a physical therapy and athletic development conditioner, available through Contemporary Designs. The machine is used by football teams, sports clinics and medical rehabilitation centers. Cardiovascular fitness and muscular strength development are promoted through both kinetic and plyometric exercises.
Gil, Ana L S; Neto, Gabriel R; Sousa, Maria S C; Dias, Ingrid; Vianna, Jeferson; Nunes, Rodolfo A M; Novaes, Jefferson S
Blood flow restriction (BFR) training stimulates muscle size and strength by increasing muscle activation, accumulation of metabolites and muscle swelling. This method has been used in different populations, but no studies have evaluated the effects of training on muscle power and submaximal strength (SS) in accounted for the menstrual cycle. The aim of this study was to analyse the effect of strength training (ST) with BFR on the muscle power and SS of upper and lower limbs in eumenorrheic women. Forty untrained women (18-40 years) were divided randomly and proportionally into four groups: (i) high-intensity ST at 80% of 1RM (HI), (ii) low-intensity ST at 20% of 1RM combined with partial blood flow restriction (LI + BFR), (iii) low-intensity ST at 20% of 1RM (LI) and d) control group (CG). Each training group performed eight training sessions. Tests with a medicine ball (MB), horizontal jump (HJ), vertical jump (VJ), biceps curls (BC) and knee extension (KE) were performed during the 1st day follicular phase (FP), 14th day (ovulatory phase) and 26-28th days (luteal phase) of the menstrual cycle. There was no significant difference among groups in terms of the MB, HJ, VJ or BC results at any time point (P>0·05). SS in the KE exercise was significantly greater in the LI + BFR group compared to the CG group (P = 0·014) during the LP. Therefore, ST with BFR does not appear to improve the power of upper and lower limbs and may be an alternative to improve the SS of lower limbs of eumenorrheic women. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
... Marie-Tooth Disease (CMT) Congenital Muscular Dystrophy (CMD) Duchenne Muscular Dystrophy (DMD) Emery-Dreifuss Muscular Dystrophy Endocrine Myopathies Metabolic Diseases of Muscle Mitochondrial Myopathies (MM) Myotonic Dystrophy (DM) Spinal-Bulbar ...
Kahn, Michelle; Williams, Gavin
The aim of this study was to investigate the relationship between a clinical test of ankle plantarflexor strength and ankle power generation (APG) at push-off during walking. This is a prospective cross-sectional study of 102 patients with traumatic brain injury. Handheld dynamometry was used to measure ankle plantarflexor strength. Three-dimensional gait analysis was performed to quantify ankle power generation at push-off during walking. Ankle plantarflexor strength was only moderately correlated with ankle power generation at push-off (r = 0.43, P < 0.001; 95% confidence interval, 0.26-0.58). There was also a moderate correlation between ankle plantarflexor strength and self-selected walking velocity (r = 0.32, P = 0.002; 95% confidence interval, 0.13-0.48). Handheld dynamometry measures of ankle plantarflexor strength are only moderately correlated with ankle power generation during walking. This clinical test of ankle plantarflexor strength is a poor predictor of calf muscle function during gait in people with traumatic brain injury.
Full Text Available OBJETIVO: Avaliar o efeito de um programa de hidroterapia na flexibilidade e na força muscular de mulheres idosas sedentárias. SUJEITOS: 31 idosas, saudáveis e sedentárias, com idade entre 65 e 70 anos (16 no grupo experimental e 15 no grupo controle. PROCEDIMENTOS: Foram realizados testes de força muscular por meio de miometria em músculos do membro superior, inferior e tronco, e realizada avaliação fotográfica da flexibilidade, utilizando os testes de envergadura e flexão anterior do tronco, antes e depois do programa, que constou de 28 sessões de uma hora e foi aplicado durante 14 semanas consecutivas. Os exercícios físicos foram organizados em sete níveis de dificuldade, selecionados visando ganho de flexibilidade e força muscular. RESULTADOS: Encontrou-se diminuição estatisticamente significativa na flexão anterior de tronco de -15,4%, o que significou uma diminuição média de 19,3 cm (±22,4 distância processo estilóide da ulna - maléolo lateral e melhora de 4,2% no teste de envergadura, o que significou um aumento médio na distância dedo - dedo de 4,7 cm (±4,5. Nos músculos abdominais, glúteos e iliopsoas não ocorreu alteração estatisticamente significativa de força, e nos músculos quadríceps femoral, isquiotibiais, bíceps braquial, peitoral maior e médio e deltóide médio, obteve-se melhora estatisticamente significativa. CONCLUSÃO:O programa de hidroterapia proposto foi eficiente para melhorar a flexibilidade e, parcialmente, a força muscular das mulheres jovens idosas que participaram do estudo. Nossos resultados são compatíveis com os encontrados em estudos similares realizados no solo.OBJECTIVE: To evaluate the effect of a hydrotherapy program on flexibility and muscle strength among sedentary elderly women. METHOD: The participants were 31 healthy sedentary elderly women aged between 65 and 70 years (16 in the experimental group and 15 in the control group. Muscle strength tests were carried
Grgic, Jozo; Trexler, Eric T; Lazinica, Bruno; Pedisic, Zeljko
Caffeine is commonly used as an ergogenic aid. Literature about the effects of caffeine ingestion on muscle strength and power is equivocal. The aim of this systematic review and meta-analysis was to summarize results from individual studies on the effects of caffeine intake on muscle strength and power. A search through eight databases was performed to find studies on the effects of caffeine on: (i) maximal muscle strength measured using 1 repetition maximum tests; and (ii) muscle power assessed by tests of vertical jump. Meta-analyses of standardized mean differences (SMD) between placebo and caffeine trials from individual studies were conducted using the random effects model. Ten studies on the strength outcome and ten studies on the power outcome met the inclusion criteria for the meta-analyses. Caffeine ingestion improved both strength (SMD = 0.20; 95% confidence interval [CI]: 0.03, 0.36; p = 0.023) and power (SMD = 0.17; 95% CI: 0.00, 0.34; p = 0.047). A subgroup analysis indicated that caffeine significantly improves upper (SMD = 0.21; 95% CI: 0.02, 0.39; p = 0.026) but not lower body strength (SMD = 0.15; 95% CI: -0.05, 0.34; p = 0.147). The meta-analyses showed significant ergogenic effects of caffeine ingestion on maximal muscle strength of upper body and muscle power. Future studies should more rigorously control the effectiveness of blinding. Due to the paucity of evidence, additional findings are needed in the female population and using different forms of caffeine, such as gum and gel.
徐红旗; 张欣; 冉令华; 杨帆; 史冀鹏; 王安利; 郑秀瑗
人体肌肉功率的发展与保持能力在完成生产劳动、日常体力活动和体育运动中具有重要的作用.本文以12名健康普通大学生为研究对象,运用模拟仿真测试评价训练系统( BTE PrimusRS)的等张测量模式来探讨人体单关节肌群功率发展与保持能力的测评方法.结果表明BTE PrimusRS系统能客观、准确地评价人体单关节肌群功率发展与保持能力的水平；此等张测试模式下,50％等长峰值肌力(或力矩)的阻力负荷设置较为合理；等长峰值肌力应采用非爆发式静力性测量模式获得.%The developmental and retentive capacity of muscular power is of great importance to human endeavor in productive labor, physical activities of daily living and sports events. Twelve healthy college students volunteered to participate in this study; the purpose was to explore the measurement method about the developmental and retentive capacity of human single -joint muscular power, combined with the mode of isotonic test on BTE PrimusRS system. The results show that BTE PrimusRS system could objectively and accurately evaluate the developmental and retentive capacity level of human single -joint muscular power. The reasonable load resistance was 50% of the isometric peak strength or torque (IPS or IPT) in the isotonic test; the mode of isometric peak strength (IPS) should be non -explosively static.
Fraser, Brooklyn J; Blizzard, Leigh; Schmidt, Michael D; Juonala, Markus; Dwyer, Terence; Venn, Alison J; Magnussen, Costan G
To assess whether childhood cardiorespiratory fitness (CRF) and muscular fitness phenotypes (strength, power, endurance) predict adult glucose homeostasis measures. Prospective longitudinal study. Study examining participants who had physical fitness measured in childhood (aged 7-15 years) and who attended follow-up clinics approximately 20 years later and provided a fasting blood sample which was tested for glucose and insulin. Physical fitness measurements included muscular strength (right and left grip, shoulder flexion, shoulder and leg extension), power (standing long jump distance) and endurance (number of push-ups in 30s), and CRF (1.6km run duration). In adulthood, fasting glucose and insulin levels were used to derive glucose homeostasis measures of insulin resistance (HOMA2-IR) and beta cell function (HOMA2-β). A standard deviation increase in childhood CRF or muscular strength (males) was associated with fasting glucose (CRF: β=-0.06mmol/L), fasting insulin (CRF: β=-0.73mU/L; strength: β=-0.40mU/L), HOMA2-IR (CRF: β=-0.06; strength: β=-0.05) and HOMA2-β (CRF: β=-3.06%; strength: β=-2.62%) in adulthood, independent of the alternative fitness phenotype (all p0.06). CRF and muscular fitness in childhood were inversely associated with measures of fasting insulin, insulin resistance and beta cell function in adulthood. Childhood CRF and muscular fitness could both be potential independent targets for strategies to help reduce the development of adverse glucose homeostasis. Copyright © 2018 Sports Medicine Australia. Published by Elsevier Ltd. All rights reserved.
Peltonen, Heikki; Walker, Simon; Lähitie, Anuliisa; Häkkinen, Keijo; Avela, Janne
This study monitored strength-training adaptations via isometric parameters throughout 2 × 10 weeks of hypertrophic (HYP I-II) or 10 weeks maximum strength (MS) followed by 10 weeks power (P) training with untrained controls. Trainees performed bilateral isometric leg press tests analyzed for peak force (maximal voluntary contraction (MVC)) and rate of force development (RFD) every 3.5 weeks. These parameters were compared with dynamic performance, voluntary and electrically induced isometric contractions, muscle activity, and cross-sectional area (CSA) in the laboratory before and after 10 and 20 weeks. RFD increased similarly during the first 7 weeks (HYP I, 44% ± 53%; MS, 48% ± 55%, P strength/power training, while MVC cannot distinguish between strength or muscle mass changes. Monitoring RFD provided important information regarding plateaus in RFD improvement, which were observed in dynamic explosive performances after HYP II compared with P.
Jandačka, Daniel; Beremlijski, Petr
The velocity of movement and applied load affect the production of mechanical power output and subsequently the extent of the adaptation stimulus in strength exercises. We do not know of any known function describing the relationship of power and velocity and load in the bench press exercise. The objective of the study is to find a function modeling of the relationship of relative velocity, relative load and mechanical power output for the bench press exercise and to determine the intensity zones of the exercise for specifically focused strength training of soccer players. Fifteen highly trained soccer players at the start of a competition period were studied. The subjects of study performed bench presses with the load of 0, 10, 30, 50, 70 and 90% of the predetermined one repetition maximum with maximum possible speed of movement. The mean measured power and velocity for each load (kg) were used to develop a multiple linear regression function which describes the quadratic relationship between the ratio of power (W) to maximum power (W) and the ratios of the load (kg) to one repetition maximum (kg) and the velocity (m•s(-1)) to maximal velocity (m•s(-1)). The quadratic function of two variables that modeled the searched relationship explained 74% of measured values in the acceleration phase and 75% of measured values from the entire extent of the positive power movement in the lift. The optimal load for reaching maximum power output suitable for the dynamics effort strength training was 40% of one repetition maximum, while the optimal mean velocity would be 75% of maximal velocity. Moreover, four zones: maximum power, maximum velocity, velocity-power and strength-power were determined on the basis of the regression function.
Jagim, Andrew R; Jones, Margaret T; Wright, Glenn A; St Antoine, Carly; Kovacs, Attila; Oliver, Jonathan M
Multi-ingredient pre-workout supplements (MIPS) are popular among resistance trained individuals. Previous research has indicated that acute MIPS ingestion may increase muscular endurance when using a hypertrophy-based protocol but less is known in regard to their effects on strength performance and high intensity running capacity. Therefore, the purpose was to determine if short-term, MIPS ingestion influences strength performance and anaerobic running capacity. In a double-blind, randomized, placebo controlled, crossover design; 12 males (19 ± 1 yrs.; 180 ± 12 cm; 89.3 ± 11 kg; 13.6 ± 4.9 %BF) had their body composition assessed followed by 5-repetition maximum (5RM) determination of back squat (BS; 119.3 ± 17.7 kg) and bench press (BP; 92.1 ± 17.8 kg) exercises. On two separate occasions subjects ingested a MIPS or a placebo (P) 30-minutes prior to performing a counter movement vertical jump test, 5 sets of 5 repetitions at 85 % of 5RM of BS and BP, followed by a single set to failure, and an anaerobic capacity sprint test to assess peak and mean power. Subjective markers of energy levels and fatigue were also assessed. Subjects returned one week later for a second testing session using counter treatment. MIPS resulted in a greater number of repetitions performed in the final set to failure in the BP (MIPS, 9.8 ± 1.7 repetitions; P, 9.1 ± 2; p = 0.03, d = 0.38), which led to a greater total volume load (set x repetitions x load) in the MIPS (753 ± 211 kg) compared to P (710 ± 226 kg; p =0.03, d = .20). MIPS ingestion improved subjective markers of fatigue (p = 0.01, d = 3.78) and alertness (p = 0.048, d = 2.72) following a bout of resistance training. An increase in mean power was observed in the MIPS condition (p = 0.03, d = 0.25) during the anaerobic sprint test. Results suggest that acute ingestion of a MIPS study may increase upper body muscular endurance. In
Matthew R. Maulit; David C. Archer; Whitney D. Leyva; Cameron N. Munger; Megan A. Wong; Lee E. Brown; Jared W. Coburn; Andrew J. Galpin
Background: Recent research has compared explosive deadlift to kettlebell training observing their effects on strength. The kettlebell swing is a popular practical exercise as it shares share a hip hinge movement with the explosive deadlift, but the two have not been compared. Objectives: The purpose of this study was to compare the effects of kettlebell swing vs. explosive deadlift training on strength and power. Methods: Thirty-one recreationally resistance-trained men (age = 23.1 ± 2.3 yea...
Sabag, Angelo; Najafi, Abdolrahman; Michael, Scott; Esgin, Tuguy; Halaki, Mark; Hackett, Daniel
The purpose of this systematic review and meta-analysis is to assess the effect of concurrent high intensity interval training (HIIT) and resistance training (RT) on strength and hypertrophy. Five electronic databases were searched using terms related to HIIT, RT, and concurrent training. Effect size (ES), calculated as standardised differences in the means, were used to examine the effect of concurrent HIIT and RT compared to RT alone on muscle strength and hypertrophy. Sub-analyses were performed to assess region-specific strength and hypertrophy, HIIT modality (cycling versus running), and inter-modal rest responses. Compared to RT alone, concurrent HIIT and RT led to similar changes in muscle hypertrophy and upper body strength. Concurrent HIIT and RT resulted in a lower increase in lower body strength compared to RT alone (ES = -0.248, p = 0.049). Sub analyses showed a trend for lower body strength to be negatively affected by cycling HIIT (ES = -0.377, p = 0.074) and not running (ES = -0.176, p = 0.261). Data suggests concurrent HIIT and RT does not negatively impact hypertrophy or upper body strength, and that any possible negative effect on lower body strength may be ameliorated by incorporating running based HIIT and longer inter-modal rest periods.
Força muscular isocinética de jogadores de futebol da seleção paraolímpica brasileira de portadores de paralisia cerebral Fuerza muscular isocinética en jugadores de futbol de la selección paraolímpica brasileña de portadores de parálisis cerebral Isokinetic muscular strength of paralympic athletes with cerebral palsy (CP from the Brazilian soccer team
Marília dos Santos Andrade
fué utilizado para analizar la deficiencia contra-lateral en relación entre los músculos flexores y extensores de la rodilla y la flaqueza muscular comparados con valores previstos para individuos normales (Neder et al., 1999. El test t-Student apareado fué utilizado para el análisis estadístico (p INTRODUCTION AND OBJECTIVE: The muscle weakness, strength asymmetries and imbalance between antagonist muscles are risk factors for knee injuries. It is possible that these risk factors increase in soccer players with cerebral palsy (CP due to their pathology and to the sport activity. Therefore, the objective of the present study was to assess the presence of these factors in paralympic athletes with CP from the Brazilian paralympic seven-a-side soccer team. METHODOLOGY: Twenty-one soccer players with CP and spastic hemiplegia were submitted to isokinetic muscle evaluation of their knees flexors and extensors muscles by means of the Cybex 6000 isokinetic dynamometer. The analysis of the muscle strength was performed with a peak torque at 60°/s. The study analyzed the contralateral deficit, the balance between flexor and extensor muscles and compared muscles weakness to the expected values for normal individuals (Neder et al. 1999. The paired t-Student test was used for the statistical analysis with p < 0.05. RESULTS: The peak torque values of the involved flexors (FPT and extensors (EPT knee muscles (FPT = 88.4 ± 26.0 Nm and EPT 155.4 ± 37.2 Nm presented significantly smaller ratios than those of the uninvolved ones (FPT = 116.2 ± 24.8 Nm and EPT = 201.6 ± 38.8 Nm. Only extensor muscles of the involved side were weaker than expected. However, the flexor muscles were weaker than expected in nine out of 21 individuals. The measures of strength of uninvolved knee muscles were not significantly different from the expected values. The average balance between flexors and extensors was within the normal range, although three individuals presented results below the
Paula Bueno de Arruda
Full Text Available The menopause represents a stage in life when modifications in the urogynecological tract occur as a decrease in the muscle strength of the pelvic floor and urethral turgidity. It is suggested that healthy muscles are thick and this enables them to support the vagina walls as well as provide a sphincteral action, favoring the closing and urethral continence. It is possible that the blood supply associated to strong muscles will promote the health of the epithelium in the area, stimulating the adequate vaginal lubrication and the delay of atrophic changes due to the age. The purpose of this study was to verify the muscle strength of the pelvic floor among healthy young and climateric women, in order to identify the existing alterations in this musculature. The study consisted of 49 women divided in two groups: Group 1 consisting of women (N=24 with an average age of 29.33 years old and Group 2, consisting of women (N=25 with an average age of 51.8 years old, submitted to the evaluation of the muscle strength of the pelvic floor by means of bidigital palpation and perineometry. Significant differences were not identified concerning the pelvic floor muscle strength by means of the perineometry in the studied groups. As for the bidigital palpation evaluation, a larger capacity of voluntary contraction and sustained maintenance of this contraction in 25 to 35-years old women was observed. O climatério representa a fase em que ocorrem modificações no trato uroginecológico, como a diminuição da força muscular do assoalho pélvico e turgidez uretral. É sugerido que músculos sadios são volumosos e isso os capacita a suportar as paredes da vagina tão bem como prover uma ação esfincteriana, favorecendo o fechamento e a continência uretral. É plausível que o suprimento de sangue associado a músculos fortes promoverá a saúde do epitélio na área, estimulando a lubrificação vaginal adequada e o retardo das mudanças atróficas da idade
Full Text Available Los cables musculares o fibras de nitinol presentan una excelente alternativa a los actuadores convencionales, con una fuerza de actuación muy alta, equivalente a la de los actuadores hidráulicos, proporcionalmente a su peso, además de su acción silenciosa. Este material, inventado en 1963, aún no es muy conocido y de ahí que se haya realizado una recopilación de sus propiedades. Entre ellas, la temperatura de transición es la más importante, por ser la que activa la aleación. Muchos sistemas se han creado para alcanzar adecuadamente la temperatura de transición, y también se continúa en la investigación de métodos que ayuden a lograr un control preciso del movimiento de la aleación con memoria de forma (SMA.
Wang, Ran; Hoffman, Jay R; Sadres, Eliahu; Bartolomei, Sandro; Muddle, Tyler W D; Fukuda, David H; Stout, Jeffrey R
Wang, R, Hoffman, JR, Sadres, E, Bartolomei, S, Muddle, TWD, Fukuda, DH, and Stout, JR. Evaluating upper-body strength and power from a single test: the ballistic push-up. J Strength Cond Res 31(5): 1338-1345, 2017-The purpose of this study was to examine the reliability of the ballistic push-up (BPU) exercise and to develop a prediction model for both maximal strength (1 repetition maximum [1RM]) in the bench press exercise and upper-body power. Sixty recreationally active men completed a 1RM bench press and 2 BPU assessments in 3 separate testing sessions. Peak and mean force, peak and mean rate of force development, net impulse, peak velocity, flight time, and peak and mean power were determined. Intraclass correlation coefficients were used to examine the reliability of the BPU. Stepwise linear regression was used to develop 1RM bench press and power prediction equations. Intraclass correlation coefficient's ranged from 0.849 to 0.971 for the BPU measurements. Multiple regression analysis provided the following 1RM bench press prediction equation: 1RM = 0.31 × Mean Force - 1.64 × Body Mass + 0.70 (R = 0.837, standard error of the estimate [SEE] = 11 kg); time-based power prediction equation: Peak Power = 11.0 × Body Mass + 2012.3 × Flight Time - 338.0 (R = 0.658, SEE = 150 W), Mean Power = 6.7 × Body Mass + 1004.4 × Flight Time - 224.6 (R = 0.664, SEE = 82 W); and velocity-based power prediction equation: Peak Power = 8.1 × Body Mass + 818.6 × Peak Velocity - 762.0 (R = 0.797, SEE = 115 W); Mean Power = 5.2 × Body Mass + 435.9 × Peak Velocity - 467.7 (R = 0.838, SEE = 57 W). The BPU is a reliable test for both upper-body strength and power. Results indicate that the mean force generated from the BPU can be used to predict 1RM bench press, whereas peak velocity and flight time measured during the BPU can be used to predict upper-body power. These findings support the potential use of the BPU as a valid method to evaluate upper-body strength and power.
Booysen, Marc Jon; Gradidge, Philippe Jean-Luc; Watson, Estelle
Unilateral balance is critical to kicking accuracy in football. In order to design interventions to improve dynamic balance, knowledge of the relationships between dynamic balance and specific neuromuscular factors such as eccentric strength and power is essential. Therefore, the aim was to determine the relationships of eccentric strength and power with dynamic balance in male footballers. The Y-balance test, eccentric isokinetic strength testing (knee extensors and flexors) and the countermovement jump were assessed in fifty male footballers (university (n = 27, mean age = 20.7 ± 1.84 years) and professional (n = 23, mean age = 23.0 ± 3.08 years). Spearman Rank Order correlations were used to determine the relationships of eccentric strength and power with dynamic balance. Multiple linear regression, adjusting for age, mass, stature, playing experience and competitive level was performed on significant relationships. Normalised reach score in the Y-balance test using the non-dominant leg for stance correlated with (1) eccentric strength of the non-dominant leg knee extensors in the university group (r = 0.50, P = 0.008) and (2) countermovement jump height in the university (r = 0.40, P = 0.04) and professional (r = 0.56, P = 0.006) football groups, respectively. No relationships were observed between eccentric strength (knee flexors) and normalised reach scores. Despite the addition of potential confounders, the relationship of power and dynamic balance was significant (r = 0.52, P power correlates moderately with dynamic balance on the non-dominant leg in male footballers.
Full Text Available Muscle strength declines with increasing age, and the power-type strength characteristics decline even more drastically than the maximal muscle strength. Therefore, it is important to design training programmes specifically for sedentary middle-aged people to effectively improve the power-type strength in leg and trunk muscles. To be suitable for the target group, the exercise programmes should be feasible, motivating and easy to practice. The aim of this study was to design and investigate the effects and feasibility of a power-type strength training programme in 226 middle-aged men and women, with 26 persons as non-training controls. The subjects trained three times a week during 22 weeks, in 12 groups with exercise classes of 10-20 subjects, and using no or very little external equipment. All training sessions were controlled and supervised by an professional instructor. Vertical squat jump, standing long jump, 20 metre running time, maximal anaerobic cycling power, maximal oxygen uptake, and angular trunk muscle flexion and extension velocities were measured before and after the training period to evaluate the training effects. Questionnaires concerning employment, physical activity, smoking, musculoskeletal symptoms and exercise motives were also filled in before and after the training period. The greatest improvements were achieved in vertical squat jump (18% and in angular trunk flexion (14% and extension (16% velocities. An external loading totalling 2.2 kg (attached in ankles increased the height in vertical squat jump by 23% and maximal anaerobic cycling power by 12%, these improvements were significant compared with subjects in no load training group (p = 0.03 in vertical squat jump and p = 0.05 in maximal anaerobic cycling power. Exercise induced injuries occurred in 19% of men and 6% of women. Low back symptoms decreased in exercisers by 12% and knee symptoms (increased by 4% during the intervention. Of all subjects, 24% dropped out
Verhoeven, Aukje A C; Adriaanse, Marieke A; Evers, Catharine; de Ridder, Denise T D
Although increasing evidence shows the importance of habits in explaining health behaviour, many studies still rely solely on predictors that emphasize the role of conscious intentions. The present study was designed to test the importance of habit strength in explaining unhealthy snacking behaviour in a large representative community sample (N= 1,103). To test our hypothesis that habits are crucial when explaining unhealthy snacking behaviour, their role was compared to the 'Power of Food', a related construct that addresses sensitivity to food cues in the environment. Moreover, the relation between Power of Food and unhealthy snacking habits was assessed. A prospective design was used to determine the impact of habits in relation to intention, Power of Food and a number of demographic variables. One month after filling out the questionnaire, including measures of habit strength and Power of Food, participants reported their unhealthy snacking behaviour by means of a 7-day snack diary. Results showed that habit strength was the most important predictor, outperforming all other variables in explaining unhealthy snack intake. The findings demonstrate that snacking habits provide a unique contribution in explaining unhealthy snacking behaviour, stressing the importance of addressing habit strength in further research and interventions concerning unhealthy snacking behaviour. ©2012 The British Psychological Society.
Baers, B.; Kall, L.; Visuri, P.
Theory and experimental verification of a novel method for measuring power signal bias and source strength in a fission reactor are reported. A minicomputer was applied in the measurements. The method is an extension of the inverse kinetics method presented by Mogilner et al. (Auth.)
de Groot, Sonja; Dallmeijer, Annet J.; Bessems, Paul J. C.; Lamberts, Marcel L.; van der Woude, Lucas H. V.; Janssen, Thomas W. J.
Objective: To compare: (i) muscle strength, sprint power and maximal aerobic capacity; and (ii) the correlations between these variables in adults with and without cerebral palsy. Design: Cross-sectional study. Subjects: Twenty adults with and 24 without cerebral palsy. Methods: Isometric and
de Groot, S.; Dallmeijer, A.J.; Bessems, P.J.C.; Lamberts, M.L.; van der Woude, L.H.V.; Janssen, T.W.J.
Objective: To compare: (i) muscle strength, sprint power and maximal aerobic capacity; and (ii) the correlations between these variables in adults with and without cerebral palsy. Design: Cross-sectional study. Subjects: Twenty adults with and 24 without cerebral palsy. Methods: Isometric and
Full Text Available The purpose of this study was to investigate the effects of plyometric and cluster resistance training on explosive power and maximum strength in karate players. Eighteen women, karate players (age mean ± SD 18.22 ± 3.02 years, mean height 163 ± 0.63cm, and mean body mass 53.25 ± 7.34 kg were selected as volunteer samples. They were divided into two groups with respect to their recorded one repetition maximum squat exercise:  plyometric training (PT=9 and  Cluster training (CT=9 groups and performed a 9-week resistance training protocol that included three stages;  General fitness (2 weeks,  Strength (4 weeks and  Power (3 weeks. Each group performed strength and power trainings for 7 weeks in stage two and three with owned protocol. The subjects were evaluated three times before stage one and after two and three stages for maximum strength and power. Data was analyzed using two way Repeated Measures (ANOVA at a significance level of (P≤0.05. The statistical analysis showed that training stages on all research variables had a significant impact. The maximum strength of the pre-test, post-test strength and post-test power were in cluster group: 29.05 ± 1.54; 32.89 ± 2.80 and 48.74 ± 4.33w and in plyometric group were 26.98 ± 1.54; 38.48 ± 2.80 and 49.82 ± 4.33w respectively. The explosive power of the pre-test, post-test strength and post-test power in cluster group were 359.32±36.20; 427.91±34.56 and 460.55±36.80w and in plyometric group were 333.90±36.20; 400.33±34.56 and 465.20±36.80w respectively. However, there were not statistically significant differences in research variables between resistance cluster and plyometric training groups after 7 weeks. The results indicated both cluster and plyometric training program seems to improve physical fitness elements at the same levels.
Ali, Ajmol; O'Donnell, Jemma; Foskett, Andrew; Rutherfurd-Markwick, Kay
The aim of this study was to examine the influence of caffeine supplementation on knee flexor and knee extensor strength before, during and after intermittent running exercise in female team-sport players taking oral contraceptive steroids (OCS). Ten healthy females (24 ± 4 years; 59.7 ± 3.5 kg; undertaking 2-6 training sessions per week) taking low-dose monophasic oral contraceptives of the same hormonal composition took part in a randomised, double-blind, placebo-controlled crossover-design trial. Sixty minutes following the ingestion of a capsule containing 6 mg∙kg -1 body mass anhydrous caffeine or artificial sweetener (placebo), participants completed a 90-min intermittent treadmill-running protocol. Isometric strength performance and eccentric and concentric strength and power of the knee flexors and knee extensors (using isokinetic dynamometer), as well as countermovement jump (CMJ), was measured before, during and after the exercise protocol, as well as ~12 h post-exercise. Blood samples were taken before, during and post-exercise to measure glucose, insulin and free fatty acids (FFA). Caffeine supplementation significantly increased eccentric strength of the knee flexors ( P performance. FFA was elevated with caffeine supplementation over time ( P caffeine intake. Caffeine supplementation increased eccentric strength and power in female team-sport players taking OCS both during an intermittent running protocol and the following morning.
Maté-Muñoz, José Luis; Monroy, Antonio J Antón; Jodra Jiménez, Pablo; Garnacho-Castaño, Manuel V
The purpose of this study was compare the effects of a traditional and an instability resistance circuit training program on upper and lower limb strength, power, movement velocity and jumping ability. Thirty-six healthy untrained men were assigned to two experimental groups and a control group. Subjects in the experimental groups performed a resistance circuit training program consisting of traditional exercises (TRT, n = 10) or exercises executed in conditions of instability (using BOSU® and TRX®) (IRT, n = 12). Both programs involved three days per week of training for a total of seven weeks. The following variables were determined before and after training: maximal strength (1RM), average (AV) and peak velocity (PV), average (AP) and peak power (PP), all during bench press (BP) and back squat (BS) exercises, along with squat jump (SJ) height and counter movement jump (CMJ) height. All variables were found to significantly improve (p velocity and jumping ability. Key PointsSimilar adaptations in terms of gains in strength, power, movement velocity and jumping ability were produced in response to both training programs.Both the stability and instability approaches seem suitable for healthy, physically-active individuals with or with limited experience in resistance training.RPE emerged as a useful tool to monitor exercise intensity during instability strength training.
Full Text Available Background: Recent studies that addressed shot speed in ice hockey have focused on the relationship between shot speed and variables such as a player's skills or hockey stick construction and its properties. There has been a lack of evidence that considers the relationship between shot speed and player strength, particularly in players at the same skill level. Objective: The aim of this study was to identify the relationship between maximal puck velocity of two shot types (the wrist shot and the slap shot and players' upper body strength and power. Methods: Twenty male professional and semi-professional ice hockey players (mean age 23.3 ± 2.4 years participated in this study. The puck velocity was measured in five trials of the wrist shot and five trials of the slap shot performed by every subject. All of the shots were performed on ice in a stationary position 11.6 meters in front of an electronic device that measures the speed of the puck. The selected strength and power variables were: muscle power in concentric contraction in the countermovement bench press with 40 kg and 50 kg measured with the FiTRODyne Premium device; bench press one-repetition maximum; and grip strength measured by digital hand dynamometer. Results: The correlations between strength/power variables and the puck velocity in the wrist shot and the slap shot ranged between .29-.72 and .16-.62, respectively. Puck velocities produced by wrist shots showed significant correlations with bench press muscle power with 40 kg (p = .004 and 50 kg (p < .001; and one-repetition maximum in bench press (p = .004. The slap shot puck velocity was significantly associated with bench press muscle power with 40 kg (p = .014 and 50 kg (p = .004. Conclusions: This study provides evidence that there are significant associations between shot speed and upper body strength and power.
Freeston, Jonathan L; Carter, Thomas; Whitaker, Gary; Nicholls, Owen; Rooney, Kieron B
Throwing velocity is an important aspect of fielding in cricket to affect run-outs and reduce the opponent's run-scoring opportunities. Although a relationship between strength and/or power and throwing velocity has been well established in baseball, water polo, and European handball, it has not been adequately explored in cricket. Consequently, this study aimed to determine the relationship between measures of strength and/or power and throwing velocity in cricket players. Seventeen male cricket players (mean ± SD; age, 21.1 ± 1.6 years; height, 1.79 ± 0.06 m; weight, 79.8 ± 6.4 kg) from an elite athlete program were tested for maximal throwing velocity from the stretch position and after a 3-meter shuffle. They were also assessed for strength and power using a range of different measures. Throwing velocity from the stretch position (30.5 ± 2.4 m·s) was significantly related to dominant leg lateral-to-medial jump (LMJ) distance (r = 0.71; p velocity and medicine ball chest pass (MB CP) distance (r = 0.67; p bench press strength (p = 0.90), height (p = 0.33), or weight (p = 0.29). Multiple regression analysis revealed that dominant MB Rot and MB CP explained 66% of the variance. The results were similar for velocity after a shuffle step (31.8 ± 2.1 m·s); however, VJ height reached statistical significance (r = 0.51; p ≤ 0.05). The multiple regression was also similar with MB Rot and MB CP explaining 70% of the variance. The cricketers in this study threw with greater velocity than elite junior and subelite senior cricketers but with lower velocities than elite senior cricketers and collegiate level and professional baseball players. This is the first study to demonstrate a link between strength and/or power and throwing velocity in cricket players and highlight the importance of power development as it relates to throwing velocity. Exercises that more closely simulated the speed (body weight jumps and medicine ball throws) or movement pattern (shoulder IR
Jørgensen, Mlk; Dalgas, U; Wens, I; Hvid, L G
Multiple sclerosis (MS) is a chronic disease in the central nervous system which causes a number of physical symptoms including impairments of muscle mechanical function (muscle strength, muscle power and explosive muscle strength (~rate of force development, RFD)). However, a full overview of the existing knowledge regarding muscle mechanical function in persons with MS (PwMS) is still pending. To systematically review 1) the psychometric properties of isokinetic dynamometry testing in PwMS, and 2) studies comparing muscle mechanical function in PwMS to matched healthy controls (HC). In addition, a meta-analysis will evaluate 3) the effects of progressive resistance training on muscle mechanical function in PwMS. A systematic literature search was performed in eight databases. To be included in the review, the study had to 1) enroll participants with a confirmed diagnosis of MS; 2) assess muscle mechanical function 3) had undergone peer-review. The psychometric properties of isokinetic dynamometry were reviewed with respect to validity, reliability, and responsiveness. Comparison of muscle strength between PwMS and HC was performed across contraction velocities, contraction modes and muscle groups, as were the rate of force development. The effects of progressive resistance training on muscle mechanical function were evaluated in a meta-analysis using a random effects model and standardized mean difference (SMD). A total of four, twenty-four, and ten studies were identified for aim 1, 2, and 3, respectively. High Intraclass correlations coefficients (range: 0.87-0.99) for isokinetic dynamometry was reported when assessing knee extensor and knee flexor muscle strength independent of contraction velocity. Compared to match HC, PwMS display impaired muscle strength, power and explosive muscle strength. Muscle strength impairments were most pronounced during maximal moderate to fast dynamic muscle contractions of the lower extremities. Progressive resistance training
A software system based on the use of the finite element method in linear and nonlinear elastomechanics was developed for assessing the strength and service life of steam generators and pressurizers for WWER type nuclear power plants. The individual programs are briefly described. They are written in FORTRAN IV, some modules are in ASSEMBLER. Programs EGUSAP, NEANKO, ROSYNA are designed for the calculation of stress and deformation, programs ROSYNA, NEANKO and NTEPLO are used for the calculation of temperature fields. Programs SPOJ and STATES are used for assessing the strength and service life of screw joints and other nodes of the WWER-440 type steam generators and pressurizers. (Z.M.)
Alterações posturais em atletas brasileiros do sexo masculino que participaram de provas de potência muscular em competições internacionais Alteraciones posturales en atletas brasileños del sexo masculino que participaron en pruebas de potencia muscular en competiciones internacionales Postural alterations in male Brazilian athletes who have participated in international muscular power competitions
Jayme Neto Júnior
la performance, bien como, prevenir la ocurrencia de lesiones deportivas. Los estudios que tengan intervención fisioterapéutica deberán evaluar si hay reducción de los efectos crónicos que las alteraciones posturales resultantes del entrenamiento causen al atleta de alto nivel.High performance sports are characterized by determining specific physical standards that overcome the geopolitical, social and cultural barriers. These peculiarities are also translated in posture alterations that are associated to the efficiency of sport gesture, and at long-term, developing chronic disease. The objective of the present study was to describe the postural profile of athletes who participate in muscular power competitions, and to identify the kinesiological processes responsible for the main body alterations. The group was composed of 15 male athletes, who participated in tests of muscular power. The protocol for data collecting was elaborated based on the proposal of Kendall for the physical observational exam, and Souchard for the postural analysis by muscular chain. All the evaluations were performed during Winnipeg 99' Pan American Games. The results showed that the ankle valgus (67% was the most common situation; the internal rotation of the hip to the right side (60%, followed by the highest opposite side (47%. This may be related with the run in curve; the hip flexor muscle and knee flexor muscle were observed in the 73% of the cases; this alteration contributes to the low back pain (73% and, in consequence, it unchains compensatory mechanism of retraction of the posterior muscular chain, causing the thoracic alteration (53% and the forefront head (73%.
Porcari, John; Hazuga, Rachel; Foster, Carl; Doberstein, Scott; Becker, Jordan; Kline, Dennis; Mickschl, Thomas; Dodge, Chris
Athletes are constantly searching for something that will give them a competitive edge. Performance jewelry is one of the latest products on the market designed to improve athletic performance. The most common claims are that wearing this performance jewelry will improve flexibility, balance, and strength. There is considerable marketing of these products, including testimonial evidence by high profile athletes, in support of the purported benefits. In demonstrations designed to validate the ...
Kwon, Seung Hee; Jang, Kyung Pil [Department of Civil and Environmental Engineering, Myongji University, Yongin (Korea, Republic of); Bang, Jin-Wook [Department of Civil Engineering, Chungnam National University, Daejeon (Korea, Republic of); Lee, Jang Hwa [Structural Engineering Research Division, Korea Institute of Construction Technology (Korea, Republic of); Kim, Yun Yong, E-mail: firstname.lastname@example.org [Structural Engineering Research Division, Korea Institute of Construction Technology (Korea, Republic of)
Highlights: • Compressive strength tests for three concrete mixes were performed. • The parameters of the humidity-adjusted maturity function were determined. • Strength can be predicted considering temperature and relative humidity. - Abstract: This study proposes a method for predicting compressive strength developments in the early ages of concretes used in the construction of nuclear power plants. Three representative mixes with strengths of 6000 psi (41.4 MPa), 4500 psi (31.0 MPa), and 4000 psi (27.6 MPa) were selected and tested under various curing conditions; the temperature ranged from 10 to 40 °C, and the relative humidity from 40 to 100%. In order to consider not only the effect of the temperature but also that of humidity, an existing model, i.e. the humidity-adjusted maturity function, was adopted and the parameters used in the function were determined from the test results. A series of tests were also performed in the curing condition of a variable temperature and constant humidity, and a comparison between the measured and predicted strengths were made for the verification.
Manuel Guillén-del Castillo
Full Text Available ResumenEl ejercicio físico puede producir estrés oxidativo en el individuo lo que pueden condicionar el riesgo cardiovascular en niños y adolescentes. Este estudio pretende analizar el estrés oxidativo según la fuerza muscular isométrica de las extremidades superiores en la edad pediátrica. Se estudiaron 70 niños sanos con edades entre 10 y 14 años, y se analizaron en saliva los lipoperóxidos (LPO, el glutatión reducido (GSH, la ratio GSH/LPO y la catalasa, como marcadores de estrés oxidativo. La muestra se dividió en dos grupos según una condición física superior o inferior medida a través de dinamometría manual (TKK 5110; se diferenció la serie en sujetos prepuberales y puberales. Se encontraron niveles significativamente inferiores de GSH y GSH/LPO en el grupo de niños con fuerza superior, y en los puberales con la mismas características; estos resultados podrían indicar la existencia de un mayor estrés oxidativo en esta situación. En conclusión, los mayores niveles de fuerza músculo esquelética, medida a través de dinamometría manual, posiblemente pueden estar asociados a un mayor estrés oxidativo en niños púberes con condición física musculoesquelética superior.AbstractPhysical exercise can produce oxidative stress, this situation could contribute cardiovascular risk in children and adolescents. The following study tries to evaluate the oxidative stress produced according to the handgrip strength in infancy. 70 healthy male subjects, ages 10 to 14 years, were studied. In the saliva samples, lipoperoxides (LPO, reduced glutathione (GSH, glutathione/lipoperoxides ratio and catalase were analyzed as biomarkers of oxidative stress. Children were divided into two groups according to their handgrip strength (high or low measured by handgrip strength (TKK 5110. The groups were also divided into prepubertal and pubertal subjects. We found GSH’s significantly low levels and of GSH/LPO in pubertal group with high
Wirth Klaus; Keiner Michael; Hartmann Hagen; Sander Andre; Mickel Christoph
Abstract The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ? 2.5 years; body height: 181.0 ? 6.8 cm; body mass: 80.2 ? 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were...
O Efeito de diferentes intervalos de recuperação entre as séries de treinamento com pesos, na força muscular em mulheres idosas treinadas The effect of different recovery intervals between sets of strength training on muscular force in trained older women
José Claudio Jambassi Filho
Full Text Available O objetivo do presente estudo foi verificar a influência de dois diferentes intervalos de recuperação (IR entre séries de repetições de treinamento com pesos (TP, no desempenho da força muscular em mulheres idosas treinadas. Dez mulheres idosas (66,6 ± 5,8 anos, com experiência prévia em TP, realizaram o seguinte protocolo: a o teste de repetições máximas (10-12RM no exercício Rosca Scott para bíceps; b com a carga encontrada no teste de 10-12RM, outras duas sessões de teste (separadas por 48 horas, agora com três séries, foram realizadas até a fadiga muscular em cada série. Dois diferentes IR foram utilizados para diferenciar essas duas sessões, isto é, numa sessão o IR era de 90 segundos (IR 90 entre as séries e na outra, de 180 segundos (IR 180. O teste t de Student para amostras dependentes mostrou que o volume total da sessão de teste com IR 180 foi estatisticamente superior (19%; P The aim of this study was to analyze the effects of two different recovery intervals (RI between repetition sets of strength training (ST on muscular strength performance in trained elderly women. Ten older women (age of 66.6 ± 5.8 with previous experience in ST, performed the following protocol: a test of maximum repetition (10-12 RM in the Scott biceps curl exercise; b two additional test sessions (48 hours apart from each other of three sets were performed until muscle fatigue in each set by applying the load found during the 10-12 RM test. Two different RI were used in these two sessions; that is, in one of the sessions the RI lasted 90 seconds (RI 90 between sets and 180 seconds in the other (RI 180. Student's t test for dependent samples showed that the total volume of the RI 180 test session was statistically superior (19%, P <0.05 compared to the RI 90 session (27.5 ± 3.4 e 23.1 ± 3.3 repetitions, respectively. The two-way 2x3 ANOVA for repeated measures in the last factor, including IR and number of repetitions for each set
Kreipke, Vince C; Allman, Brittany R; Kinsey, Amber W; Moffatt, Robert J; Hickner, Robert C; Ormsbee, Michael J
Although multi-ingredient performance supplements (MIPS) have increased in popularity because of their array of ergogenic ingredients, their efficacy and safety remain in question. The objective of this study was to determine the impact of supplementation with T+ (SUP; Onnit Labs, Austin, TX, USA), an MIPS containing long jack root, beta-alanine, and branched-chain amino acids, and other proprietary blends, on strength, body composition, and hormones in young resistance-trained men. Subjects were randomized to consume either T+ (SUP; n = 14; age, 21 ± 3 years; body fat, 18.3 ± 4.7%) or an isocaloric placebo (PL; n = 13; age, 21 ± 3 years; body fat, 21.5 ± 6.2%) for 4 weeks. Both groups underwent a progressive, 4-week high-intensity resistance training protocol. Before and after the training protocol, mood state, body composition, blood hormones (also collected at midpoint), and maximal strength were measured. SUP had significantly greater increases in bench press (SUP, 102 ± 16 kg to 108 ± 16 kg vs. PL, 96 ± 22 kg to 101 ± 22 kg; p < 0.001) and total weight lifted (SUP, 379 ± 59 kg to 413 ± 60 kg vs. PL, 376 ± 70 kg to 400 ± 75 kg; p < 0.001) compared with PL. Additionally, deadlift strength relative to total body mass (calculated as weight lifted/body mass; kg:kg) (2.08 ± 0.18 to 2.23 ± 0.16; p = 0.036) and lean mass (2.55 ± 0.19 to 2.72 ± 0.16; p = 0.021) increased significantly in SUP but not PL (2.02 ± 0.30 to 2.15 ± 0.36 and 2.56 ± 0.31 to 2.70 ± 0.36, respectively). No other significant differences were detected between groups for the remaining variables. Supplementing with SUP enhanced resistance training adaptations independent of hormonal status, and thus SUP use may warrant inclusion into peri-workout nutrition regimens. This study was registered with clinicaltrials.gov (identifier: NCT01971723).
Nimphius, Sophia; McGuigan, Michael R; Newton, Robert U
The purpose of this study was to investigate (a) the cross-sectional relationship of strength, power, and performance variables in trained female athletes and (b) determine if the relationship between these variables changes over the course of a season. Ten female softball players (age = 18.1 +/- 1.6 years, height = 166.5 +/- 8.9 cm, and weight = 72.4 +/- 10.8 kg) from a state Australian Institute of Sport softball team were tested for maximal lower body strength (one repetition maximum [1RM]), peak force (PF), peak velocity (PV), and peak power (PP) during jump squats unloaded and loaded, unloaded countermovement vertical jump height (VJH) 1 base and 2 base sprint performance and change of direction performance on dominant and nondominant sides. The testing sessions occurred pre, mid, and post a 20-week training period. Relationship between body weight (BW), relative strength (1RM/BW), VJH, relative PP, relative PF, PV, speed, and change of direction variables were assessed by Pearson product-moment correlation coefficient at each testing session. Significant relationships were found across all time points with BW, speed, and change of direction measures (r = 0.70-0.93) and relative strength and measures of speed and change of direction ability (r = -0.73-0.85). There were no significant relationships between VJH and any measure of performance at any time point. In conclusion, BW and relative strength have strong to very strong correlations with speed and change of direction ability, and these correlations remain consistent over the course of the season. However, it seems as if many relationships vary with time, and their relationships should therefore be investigated longitudinally to better determine if these cross-sectional relationships truly reflect a deterministic relationship.
Muscle strength assessment among children and adolescents with growing pains and joint hypermobility Avaliação da força muscular em crianças e adolescentes com dores de crescimento e hipermobilidade articular
Full Text Available OBJECTIVE: To compare the muscle strength of children and adolescents with growing pains, with and without joint hypermobility, to healthy controls by means of quantitative tests. METHOD: Forty-seven children and adolescents were monitored because of growing pains: 24 with joint hypermobility (GP-JH group and 23 without joint hypermobility (GP group. These cases, along with 47 healthy controls matched for age and gender, underwent two quantitative tests for muscle strength evaluation: the Childhood Myositis Assessment Scale (CMAS and the Manual Muscle Strength Test (MMT. Anthropometric data such as height, weight, body mass index, triceps skinfold, mean arm circumference and arm muscle area were compared between the three groups. RESULTS: The three groups did not present any statistical differences in anthropometric measurements. There were significant differences in median CMAS scores, which were lower in the GP (47; range 39-52 and GP-JH (46; range 40-51 groups than the control group (50; range 45-52; pOBJETIVO: Avaliar, por meio de teste quantitativo, a força muscular em crianças e adolescentes com dores de crescimento, associada ou não com hipermobilidade articular e comparadas com controles saudáveis. MÉTODO: Quarenta e sete casos de crianças e adolescentes acompanhados por dores de crescimento, sendo 24 com hipermobilidade articular (DC-HA, 23 sem hipermobilidade articular (DC e 47 controles saudáveis pareados por idade e gênero foram submetidos a dois testes quantitativos para a avaliação da força muscular, o Childhood Myositis Assessment Scale (CMAS e o Manual Muscle Strength Test (MMT. Os dados antropométricos como altura, peso, índice de massa corporal, prega cutânea tricipital, circunferência média do braço e a área muscular do braço foram comparados entre os três grupos. RESULTADOS: Os três grupos não apresentaram diferença estatística entre as medidas antropométricas. Houve diferença significante entre a
Mike, Jonathan N; Cole, Nathan; Herrera, Chris; VanDusseldorp, Trisha; Kravitz, Len; Kerksick, Chad M
Mike, JN, Cole, N, Herrera, C, VanDusseldorp, T, Kravitz, L, and Kerksick, CM. The effects of eccentric contraction duration on muscle strength, power production, vertical jump, and soreness. J Strength Cond Res 31(3): 773-786, 2017-Previous research has investigated the effects of either eccentric-only training or comparing eccentric and concentric exercise on changes related to strength and power expression, but no research to date has investigated the impact of altering the duration of either the concentric or the eccentric component on these parameters. Therefore, the purpose of this study was to assess the duration of eccentric (i.e., 2-second, 4-second vs. 6-second) muscle contractions and their effect on muscle strength, power production, vertical jump, and soreness using a plate-loaded barbell Smith squat exercise. Thirty college-aged men (23 ± 3.5 years, 178 ± 6.8 cm, 82 ± 12 kg, and 11.6 ± 5.1% fat) with 3.0 ± 1.0 years of resistance training experience and training frequency of 4.3 ± 0.9 days per week were randomized and assigned to 1 of 3 eccentric training groups that incorporated different patterns of contraction. For every repetition, all 3 groups used 2-second concentric contractions and paused for 1 second between the concentric and eccentric phases. The control group (2S) used 2-second eccentric contractions, whereas the 4S group performed 4-second eccentric contractions and the 6S group performed 6-second eccentric contractions. All repetitions were completed using the barbell Smith squat exercise. All participants completed a 4-week training protocol that required them to complete 2 workouts per week using their prescribed contraction routine for 4 sets of 6 repetitions at an intensity of 80-85% one repetition maximum (1RM). For all performance data, significant group × time (G × T) interaction effects were found for average power production across all 3 sets of a squat jump protocol (p = 0.04) while vertical jump did not reach
Full Text Available Strength training, or resistance training, is a form of physical conditioning used to increase the ability to resist force. Since muscular strength is required for success in many sports, it is logical to assume that stronger and more powerful young athletes will achieve better results. The aim of the study was to examine the effects of strength training on young athletes. An eight-week strength training program for developing muscle strength was performed in this study. Training protocol was designed specifically for young adolescent’s athletes. The program consisted of exercises for lower and upper body, abdominal and lower back muscles. The programs did not involve the maximal (1-3 repetitions maximum and other very hard intensity exercises that may had negative effect on young athletes. The results showed that strength training program had positive effects on maximal isometric muscle force (Fmax and motor skill. The increase presents the combined influence of strength training and growth.
Murray, Amanda M; Thomas, Abbey C; Armstrong, Charles W; Pietrosimone, Brian G; Tevald, Michael A
Abnormal knee joint mechanics have been implicated in the pathogenesis and progression of knee osteoarthritis. Deficits in muscle function (i.e., strength and power) may contribute to abnormal knee joint loading. The associations between quadriceps strength, power and knee joint mechanics remain unclear in knee osteoarthritis. Three-dimensional motion analysis was used to collect peak knee joint angles and moments during the first 50% of stance phase of gait in 33 participants with knee osteoarthritis. Quadriceps strength and power were assessed using a knee extension machine. Strength was quantified as the one repetition maximum. Power was quantified as the peak power produced at 40-90% of the one repetition maximum. Quadriceps strength accounted for 15% of the variance in peak knee flexion angle (P=0.016). Quadriceps power accounted for 20-29% of the variance in peak knee flexion angle (Pknee adduction moment (P=0.05). These data suggest that quadriceps power explains more variance in knee flexion angle and knee adduction moment during gait in knee osteoarthritis than quadriceps strength. Additionally, quadriceps power at multiple loads is associated with knee joint mechanics and therefore should be assessed at a variety of loads. Taken together, these results indicate that quadriceps power may be a potential target for interventions aimed at changing knee joint mechanics in knee osteoarthritis. Copyright © 2015 Elsevier Ltd. All rights reserved.
Jia Xiaofeng; Zhou Guofeng; Bi Xiangjun; Ji Shunying
The refueling machine of PWR plays important roles in nuclear power plant operation,and the dynamic analysis and strength assessment should be carried out to check its safety. In this paper, the finite element model (FEM) was established with the software ANSYS 12 for the refueling machine structure of large 1 000 MW PWR. The dynamic computations were performed under three work conditions, i.e. normal (cart starting and braking), abnormal (OBE) and accident(SSE) conditions, respectively. The structure responses (internal force and stress) of refueling machine under earthquake response spectrum in three directions were combined with the method of square root of square sum (SRSS). Moreover, the static response under gravity was also considered to construct the most critical conditions. With the simulated results, the strength of main structure, bold and weld joint,and the stability of landing leg for additional crane were assessed based on the RCCM code. At last, the local stress analysis of finger-form hook, which function is to take fuel assemblies, was also analyzed, while its strength was also assessed. The results show that the strengths of the refueling machine under various working conditions can meet the safety requirements. (authors)
Full Text Available The aim of this research was to develop different regression models to predict 2000 m rowing ergometer performance with the use of anthropometric, anaerobic and strength variables and to determine how precisely the prediction models constituted by different variables predict performance, when conducted together in the same equation or individually. 38 male collegiate rowers (20.17 ± 1.22 years participated in this study. Anthropometric, strength, 2000 m maximal rowing ergometer and rowing anaerobic power tests were applied. Multiple linear regression procedures were employed in SPSS 16 to constitute five different regression formulas using a different group of variables. The reliability of the regression models was expressed by R2 and the standard error of estimate (SEE. Relationships of all parameters with performance were investigated through Pearson correlation coefficients. The prediction model using a combination of anaerobic, strength and anthropometric variables was found to be the most reliable equation to predict 2000 m rowing ergometer performance (R2 = 0.92, SEE= 3.11 s. Besides, the equation that used rowing anaerobic and strength test results also provided a reliable prediction (R2 = 0.85, SEE= 4.27 s. As a conclusion, it seems clear that physiological determinants which are affected by anaerobic energy pathways should also get involved in the processes and models used for performance prediction and talent identification in rowing.
Wing, Christopher E; Turner, Anthony N; Bishop, Chris J
The purpose of this investigation was to examine the importance of strength and power in relation to key performance indicators (KPI's) within competitive soccer match play. This was achieved through using an experimental approach where fifteen subjects were recruited from a professional soccer club's scholarship squad during the 2013/14 season. Following anthropometric measures, power and strength were assessed across a range of tests which included the squat jump (SJ), countermovement jump (CMJ), 20 metre (m) sprint and arrowhead change of direction test. A predicted 1-repetition maximum (RM) was also obtained for strength by performing a 3RM test for both the back squat and bench press and a total score of athleticism (TSA) was provided by summing z-scores for all fitness tests together, providing one complete score for athleticism. Performance analysis data was collected during 16 matches for the following KPIs: passing, shooting, dribbling, tackling and heading. Alongside this, data concerning player ball involvements (touches) was recorded. Results showed that there was a significant correlation (p soccer performance, particularly when players are required to win duels of a physical nature. There were no other relationships found between the fitness data and the KPI's recorded during match play which may indicate that other aspects of player's development such as technical skill, cognitive function and sensory awareness are more important for soccer-specific performance.
Maté-Muñoz, José Luis; Monroy, Antonio J. Antón; Jodra Jiménez, Pablo; Garnacho-Castaño, Manuel V.
The purpose of this study was compare the effects of a traditional and an instability resistance circuit training program on upper and lower limb strength, power, movement velocity and jumping ability. Thirty-six healthy untrained men were assigned to two experimental groups and a control group. Subjects in the experimental groups performed a resistance circuit training program consisting of traditional exercises (TRT, n = 10) or exercises executed in conditions of instability (using BOSU® and TRX®) (IRT, n = 12). Both programs involved three days per week of training for a total of seven weeks. The following variables were determined before and after training: maximal strength (1RM), average (AV) and peak velocity (PV), average (AP) and peak power (PP), all during bench press (BP) and back squat (BS) exercises, along with squat jump (SJ) height and counter movement jump (CMJ) height. All variables were found to significantly improve (p <0.05) in response to both training programs. Major improvements were observed in SJ height (IRT = 22.1%, TRT = 20.1%), CMJ height (IRT = 17.7%, TRT = 15.2%), 1RM in BS (IRT = 13.03%, TRT = 12.6%), 1RM in BP (IRT = 4.7%, TRT = 4.4%), AP in BS (IRT = 10.5%, TRT = 9.3%), AP in BP (IRT = 2.4%, TRT = 8.1%), PP in BS (IRT=19.42%, TRT = 22.3%), PP in BP (IRT = 7.6%, TRT = 11.5%), AV in BS (IRT = 10.5%, TRT = 9.4%), and PV in BS (IRT = 8.6%, TRT = 4.5%). Despite such improvements no significant differences were detected in the posttraining variables recorded for the two experimental groups. These data indicate that a circuit training program using two instability training devices is as effective in untrained men as a program executed under stable conditions for improving strength (1RM), power, movement velocity and jumping ability. Key Points Similar adaptations in terms of gains in strength, power, movement velocity and jumping ability were produced in response to both training programs. Both the stability and instability approaches
Full Text Available Purpose. Simplification of accounting ratio to determine the magnetic field strength of electric power lines, and assessment of their environmental safety. Methodology. Description of the transmission lines of the magnetic field by using techniques of spatial harmonic analysis in the cylindrical coordinate system is carried out. Results. For engineering calculations of electric power lines magnetic field with sufficient accuracy describes their first spatial harmonic magnetic field. Originality. Substantial simplification of the definition of the impact of the construction of transmission line poles on the value of its magnetic field and the bands of land alienation sizes. Practical value. The environmentally friendly projection electric power lines on the level of the magnetic field.
Gabbard, Carl P.; And Others
The upper body muscular endurance of males and females 2-5 years of age was assessed, and relationships relative to sex, age, endurance and selected anthropometric measures were investigated. None of the relationships were found to be of practical predicative value; while upper body muscular strength increased with age, no significant differences…
Força muscular respiratória e capacidade funcional em idosas hipertensas com sonolência diurna excessiva Respiratory muscle strength and physical fitness in hypertensive elderly women with excessive daytime sleepiness
Full Text Available O objetivo do estudo foi verificar se a sonolência diurna excessiva (SDE afeta a capacidade funcional (CF e força muscular respiratória entre idosas hipertensas. O estudo avaliou 32 idosas hipertensas, divididas em dois grupos (com SDE, n=17, 64,9±5,3 anos; e sem SDE, n=15, 65,9±5,5 anos, quanto a: força muscular respiratória, por manovacuometria; CF, pelo Questionário para avaliação de limitação das atividades e por testes de aptidão funcional; nível de atividade física, pelo questionário internacional de atividade física IPAQ; grau de SDE, pela escala de sonolência de Epworth; qualidade do sono, pelo índice de qualidade do sono de Pittsburgh; e intensidade do ronco, pela escala de ronco de Stanford. Os dois grupos, homogêneos quanto a características antropométricas e da hipertensão, foram comparados estatisticamente quanto a parâmetros de sono, pressões respiratórias máximas, nível de atividade física e CF. Foi encontrada diferença significativa na qualidade do sono (p=0,03, tendo as hipertensas com SDE qualidade de sono muito ruim; porém não foram encontradas diferenças significativas entre os grupos nas pressões inspiratória e expiratória máximas, nem quanto aos testes de CF. Conclui-se que a força dos músculos respiratórios não sofre alteração em decorrência da presença de SDE em idosas hipertensas e que essa sonolência não interfere na capacidade funcional.The purpose of the study was to inquire whether excessive daytime sleepiness (EDS affects functional capacity (FC and respiratory muscle strength in elderly hypertensive patients. Thirty-two elderly hypertensive female patients were divided into two groups (with EDS, n=17, mean age 64.9±5.3; without EDS, n=15, mean age 65.9±5.5 and were assessed as to respiratory muscle strength by spirometry; FC, by the Questionnaire on limitations in physical activities and by functional fitness tests; physical activity level, by the International
Matthew R. Maulit
Full Text Available Background: Recent research has compared explosive deadlift to kettlebell training observing their effects on strength. The kettlebell swing is a popular practical exercise as it shares share a hip hinge movement with the explosive deadlift, but the two have not been compared. Objectives: The purpose of this study was to compare the effects of kettlebell swing vs. explosive deadlift training on strength and power. Methods: Thirty-one recreationally resistance-trained men (age = 23.1 ± 2.3 years, height = 175.5 ± 6.6 cm, mass = 83.9 ± 13.8 kg, 1RM deadlift = 159.9 ± 31.7 kg were randomly assigned to one of two groups [kettlebell swing group (KBG n = 15, or explosive deadlift group (EDLG n = 16]. Vertical jump height, isometric mid-thigh pull (MTP, and 1RM deadlift were measured pre and post training. Both groups trained twice per week for 4 weeks. Volume and load were increased after the first 2 weeks of training. Results: A 2 (time x 2 (group mixed factor ANOVA revealed a significant (P<0.05 increase in deadlift 1RM (pre: 159.9 ± 31.7 kg, post: 168.9 ± 31.8 kg and vertical jump height (pre: 56.6 ± 9.9 cm, post: 57.9 ± 9.7 cm for both groups, but were not significantly different between groups. There were no significant changes in MTP. Conclusions: Strength and conditioning professionals may use both kettlebell swings and explosive deadlifts to increase deadlift strength and vertical jump power.
Zemková, Erika; Jeleň, Michal; Kováčiková, Zuzana; Miklovič, Peter; Svoboda, Zdeněk; Janura, Miroslav
The authors investigate the ways in which varied postural responses to translating platform perturbations are associated with the variables of strength and power. Twenty-four physically active and 27 sedentary young adults were exposed to a set of postural perturbations at varied velocities (10 and 20 cm/s) and the respective accelerations (6.4 and 6.9 m/s 2 ), constant distance (6 cm), and 4 directions of platform motion (forward, backward, left-lateral, and right-lateral). They also performed maximum voluntary isometric contraction (MVC) and chair rising/chair jumping tests. The analysis of variance revealed significant interaction effect for peak center of pressure displacement, direction by velocity: F 3,129 = 24.43, p = .002; and direction by acceleration: F 3,129 = 34.18, p = .001. There were no significant correlations between peak center of pressure displacements and peak force and peak rate of force development measured during MVC in either standing (r = .27-57) or sitting positions (r = .12-51) and peak power during chair jumping (r = .47-.59) in all participants. As such, only a small proportion of variance was explained (9-39%, 3-23%, and 23-41%, respectively). In conclusion, interaction effects indicate that the composition of stimuli strongly influences compensatory responses and this effect is more pronounced in sedentary than in physically active young adults. Nevertheless, the dynamic balance is not associated with muscle strength and power in either group.
José Luis Maté-Muñoz
Full Text Available The purpose of this study was compare the effects of a traditional and an instability resistance circuit training program on upper and lower limb strength, power, movement velocity and jumping ability. Thirty-six healthy untrained men were assigned to two experimental groups and a control group. Subjects in the experimental groups performed a resistance circuit training program consisting of traditional exercises (TRT, n = 10 or exercises executed in conditions of instability (using BOSU® and TRX® (IRT, n = 12. Both programs involved three days per week of training for a total of seven weeks. The following variables were determined before and after training: maximal strength (1RM, average (AV and peak velocity (PV, average (AP and peak power (PP, all during bench press (BP and back squat (BS exercises, along with squat jump (SJ height and counter movement jump (CMJ height. All variables were found to significantly improve (p <0.05 in response to both training programs. Major improvements were observed in SJ height (IRT = 22.1%, TRT = 20.1%, CMJ height (IRT = 17.7%, TRT = 15.2%, 1RM in BS (IRT = 13.03%, TRT = 12.6%, 1RM in BP (IRT = 4.7%, TRT = 4.4%, AP in BS (IRT = 10.5%, TRT = 9.3%, AP in BP (IRT = 2.4%, TRT = 8.1%, PP in BS (IRT=19.42%, TRT = 22.3%, PP in BP (IRT = 7.6%, TRT = 11.5%, AV in BS (IRT = 10.5%, TRT = 9.4%, and PV in BS (IRT = 8.6%, TRT = 4.5%. Despite such improvements no significant differences were detected in the posttraining variables recorded for the two experimental groups. These data indicate that a circuit training program using two instability training devices is as effective in untrained men as a program executed under stable conditions for improving strength (1RM, power, movement velocity and jumping ability.
Kevin A. Murach
Full Text Available Taper, or reduced-volume training, improves competition performance across a broad spectrum of exercise modes and populations. This article aims to highlight the physiological mechanisms, namely in skeletal muscle, by which taper improves performance and provide a practical literature-based rationale for implementing taper in varied athletic disciplines. Special attention will be paid to strength- and power-oriented athletes as taper is under-studied and often overlooked in these populations. Tapering can best be summarized by the adage “less is more” because maintained intensity and reduced volume prior to competition yields significant performance benefits.
Li Zhong; Zuo Weiwei
This paper briefly describes the related technical requirement of secondary grouting during the process of equipment installation in nuclear power projects. The method and procedure are introduced in detail from the aspects of acceptance, preparation, pouring, collecting and maintenance of the high-strength non-shrinking based pouring cement material, and the cautions during the construction is also provided. The factors affecting the quality of the field grouting is analyzed, and the measures to reduce or eliminate the micro-cracks during the process is provided. (authors)
Wirth, Klaus; Keiner, Michael; Hartmann, Hagen; Sander, Andre; Mickel, Christoph
The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg) joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development) were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance.
Entrenamiento de la fuerza muscular como coadyuvante en la disminución del riesgo cardiovascular: una revisión sistemática Muscle strength training as co-adjuvant in cardiovascular risk reduction: a systematic review
Isabel A Sánchez
Full Text Available La fuerza muscular es una cualidad física importante dentro del desarrollo de las actividades básicas del ser humano, pese a que ha sido uno de los elementos poco trabajados dentro de la población con riesgo cardiovascular, debido a que no se poseen conceptos claros que hagan referencia a los efectos fisiológicos que se obtienen, los cuales siempre han sido motivo de discusión y de diferentes posturas para muchos investigadores. El objetivo de este artículo es mostrar con claridad los efectos fisiológicos que se logran con el entrenamiento de la fuerza, a través de una revisión sistemática. Para ello se tuvieron en cuenta 54 artículos de diferentes bases de datos, con el fin de contemplar las distintas conceptualizaciones realizadas por aquellos autores que se han dedicado al estudio de esta cualidad física. Estos autores tuvieron en cuenta aspectos tales como el entrenamiento de la fuerza muscular y los beneficios que se obtienen tras el entrenamiento de la misma, haciendo especial énfasis en lo referente al sistema cardiovascular desde el punto de vista hemodinámico, a nivel del sistema metabólico. Así, analizaron variables tales como ritmo metabólico y sensibilidad a la insulina y perfil lipídico, a fin de dar a conocer los fundamentos fisiológicos que faciliten posteriormente emplearlas como herramienta que favorezca no sólo el retorno a la funcionalidad del individuo, sino que, de manera concomitante, permitan disminuir aquellos índices generadores de patologías que se consideran como desencadenantes de riesgos cardiovasculares, de forma potencial en la población con riesgo cardiovascular. Concluyen que para que la información sea más representativa, es importante incentivar a los investigadores en la realización de más estudios aplicativos, que permitan demostrar que el entrenamiento de la fuerza muscular logra contribuir a la reducción de factores de riesgo cardiovascular aunque de una forma más lenta que el
Efeitos do treinamento de resistência na força muscular e níveis de fadiga em pacientes com câncer de mama Los efectos de los ejercicios de resistencia sobre varios músculos y niveles de fatiga en pacientes con cáncer de mama The effects of resistance training on muscular strength and fatigue levels in breast cancer patients
experimental se ejercitó después de una cirugía durante 60 minutos, de forma moderada, dos veces por semana, durante 21 semanas. La fuerza muscular total fue evaluada antes y después del tratamiento y los niveles de fatiga fueron evaluados en cuatro momentos durante los ejercicios. Fueron encontradas diferencias significativas en la fuerza muscular total entre los grupos después de los ejercicios (p = 0,025. Los niveles de fatiga disminuyeron significativamente entre los grupos después de la primera (p = 0,001 y la segunda (p = 0,005 intervención y al final del tratamiento (p = 0,001. Los resultados de este estudio sugieren que los ejercicios resistidos deben ser incluidos en la prescripción de ejercicios de combate a la fatiga y en la mejoría de la fuerza muscular en mujeres con cáncer de mama sometidas a tratamiento.The effects of generalized exercise programs to combat cancer and cancer treatment-related side effects have been extensively reported in the literature. The purpose of this study was to examine the effects of an individualized exercise program with emphasis on resistance exercise, changes in muscular strength and fatigue in breast cancer female patients under treatment. Twenty subjects were randomly divided in two groups: an experimental (57.5 ± 23.0 years and a control (56.6 ± 16.0 years group. A twenty-one week intervention involving pre- and post-functional assessments, prescriptive exercise, and three moments of fatigue measures was used. The experimental group exercised at a low to moderate-intensity for sixty minutes two days a week beginning after surgery. Significant differences in overall muscular strength were observed between groups post-intervention (p = 0.025. Fatigue was also significantly different between groups at treatment one (p = 0.001, treatment two (p = 0.005 and post-intervention (p = 0.001. The results of this study suggest that an emphasis on resistance training should be utilized to combat fatigue and to increase muscular
Angélica Mércia Pascon Barbosa
Full Text Available OBJETIVO: analisar a influência da via de parto sobre a força muscular do assoalho pélvico (FM-AP. MÉTODOS: estudo clínico de corte transversal, para avaliar a FM-AP pelo teste da avaliação da força do assoalho pélvico (AFA e uso do perineômetro em primíparas, entre 20-30 anos de idade, 4-6 meses pós-parto. A contração, medida pelos dois testes, foi classificada em: zero - ausência, um - leve, dois - moderada e três - normal, sustentada por 6 segundos. Avaliaram-se 94 mulheres, entre 20 e 30 anos, divididas em três grupos: pós-parto vaginal (n=32; pós-cesárea (n=32 e nulíparas (n=30. A variável independente foi a via de parto e a dependente, a FM-AP. A comparação entre os graus de contração foi realizada pelo teste de Kruskal-Wallis e o teste de Dunn para comparações múltiplas; a influência da via de parto pelo teste chi2, o risco relativo (RR para alteração da FM-AP e o coeficiente kappa para avaliar equivalência entre os testes. RESULTADOS: a mediana e 1º e 3º quartil da FM-AP foram menores (p=0,01 pós-parto vaginal (2,0;1-2 e intermediários pós-cesárea (2,0; 2-3 em relação às nulíparas (3,0;2-3, tanto analisadas pelo AFA como pelo perineômetro. Aumentou o RR de exame alterado pós-parto vaginal (RR=2,5; IC 95%: 1,3-5,0; p=0,002; (RR=2,3; IC 95%: 1,2-4,3; p=0,005 e pós-cesárea (RR=1,5; IC 95%: 0,94-2,57; p=0,12; (RR=1,3; IC 95%: 0,85-2,23; p=0,29 pelo PFSE e perineômetro, respectivamente. CONCLUSÕES: o parto vaginal diminuiu a força muscular do AP de primíparas quando comparado com os casos submetidos à cesárea e com as nulíparas.PURPOSE: to evaluate the influence of the delivery route on pelvic floor (PF muscle strength. METHODS: a cross-sectional study was conducted to evaluate PF muscle strength by the pelvic floor strength evaluation (PFSE test and perineometer in primiparous patients aged 20 to 30 years 4 to 6 months after delivery. The categorization was: zero lack of muscle
Cormie, Prue; McGuigan, Michael R; Newton, Robert U
To determine whether the magnitude of performance improvements and the mechanisms driving adaptation to ballistic power training differ between strong and weak individuals. Twenty-four men were divided into three groups on the basis of their strength level: stronger (n = 8, one-repetition maximum-to-body mass ratio (1RM/BM) = 1.97 +/- 0.08), weaker (n = 8, 1RM/BM = 1.32 +/- 0.14), or control (n = 8, 1RM/BM = 1.37 +/- 0.13). The stronger and weaker groups trained three times per week for 10 wk. During these sessions, subjects performed maximal-effort jump squats with 0%-30% 1RM. The impact of training on athletic performance was assessed using a 2-d testing battery that involved evaluation of jump and sprint performance as well as measures of the force-velocity relationship, jumping mechanics, muscle architecture, and neural drive. Both experimental groups showed significant (P < or = 0.05) improvements in jump (stronger: peak power = 10.0 +/- 5.2 W.kg, jump height = 0.07 +/- 0.04 m; weaker: peak power = 9.1 +/- 2.3 W.kg, jump height = 0.06 +/- 0.04 m) and sprint performance after training (stronger: 40-m time = -2.2% +/- 2.0%; weaker: 40-m time = -3.6% +/- 2.3%). Effect size analyses revealed a tendency toward practically relevant differences existing between stronger and weaker individuals in the magnitude of improvements in jump performance (effect size: stronger: peak power = 1.55, jump height = 1.46; weaker: peak power = 1.03, jump height = 0.95) and especially after 5 wk of training (effect size: stronger: peak power = 1.60, jump height = 1.59; weaker: peak power = 0.95, jump height = 0.61). The mechanisms driving these improvements included significant (P < or = 0.05) changes in the force-velocity relationship, jump mechanics, and neural activation, with no changes to muscle architecture observed. The magnitude of improvements after ballistic power training was not significantly influenced by strength level. However, the training had a tendency toward
Li, Yumeng; Kakar, Rumit S; Fu, Yang-Chieh; Mahoney, Ormonde M; Kinsey, Tracy L; Simpson, Kathy J
Unicompartmental knee arthroplasty (UKA) has been shown to demonstrate some satisfactory short-term outcomes. However, to our knowledge, there have been no reports on midterm or long-term knee extensor strength and leg extensor power post-UKA. Therefore, the purposes of this study were: (1) to assess the isokinetic knee extensor strength, leg extensor power and stair performance of elderly participants at 5 years UKA post-operation; (2) to compare the differences in knee extensor strength and leg extensor power between the UKA and contralateral healthy limbs. Nineteen elderly participants (75 ± 5 years) who had a medial or a lateral compartment UKA at 5 years post-operation were recruited. The isokinetic knee extensor strength and leg extensor power were measured. The stair performance was tested on a 4-step stair, and ascent and descent velocities were calculated. The pain level was assessed. The UKA limbs' knee extensor strength and leg extensor power were 1.01 ± 0.39 Nm/kg and 0.98 ± 0.27 W/kg, respectively. The stair ascent and descent velocities were 0.37 ± 0.07 and 0.38 ± 0.11 m/s, respectively. In addition, the UKA limbs exhibited comparable knee strength and leg power relative to the contralateral limbs. In general, the knee extensor strength and leg extensor power exhibited by the UKA limbs at 5 years post-operation may be typical in comparison with the normative data. We suggest that UKA is a satisfactory treatment in regard to the recovery of knee strength, leg power and ability to climb up and down stairs.
Stojanovic, M D; Ostojic, S M; Calleja-González, J; Milosevic, Z; Mikic, M
The aim of this study was to examine the relationship between explosive strength and aerobic power with basketball-specific repeated sprint ability in elite male basketball players. Twenty-four elite basketball players (age 22.2±3.4 years, height 197.1±6.2 cm, weight 95.7±8.8 kg; training experience 11.0±3.1 years; mean±SD), participated in the study. Subjects performed countermovement jump (CMJ) test and incremental pseudo-ramp test protocol with measured CMJ height and VO2max, respectively. Specific repeated sprint ability (RSA) test was conducted, with total sprinting time (summation of 10 sprint times - RSAtot) and sprint decrement (fatigue index - RSAFI) calculated. Significant decrements in sprint performance from the eight 30-m sprint (Pbasketball players. It seems that coaches and strength and conditioning professionals should devote additional time for explosive strength development in elite basketball players during preparatory period to enhance RSA performance.
Estudo de associação entre força muscular e massa magra em mulheres idosas Estudio de la asociación entre fuerza muscular y masa magra en mujeres mayores Association between muscle strength and fat-free mass in older women
Ricardo Moreno Lima
Full Text Available O objetivo do presente estudo foi verificar a associação entre a força muscular isocinética da musculatura extensora do joelho do membro dominante com a MM de diferentes segmentos corporais, em mulheres idosas. Um total de 258 idosas (66,58±5,6anos; 65,6±11,7kg; 1,53±0,07m foram submetidas à avaliação isocinética do pico de torque (PT e da MM (DXA. Correlações de Pearson foram examinadas entre os índices de MM dos braços, das pernas, do tronco, do corpo inteiro, da perna dominante (MMB, MMP, MMT, MMI, MMPD, respectivamente com o PT. O nível de significância foi de El objetivo de este estudio fue correlacionar la fuerza muscular de los extensores de la rodilla con la Masa Magra (MM en diferentes segmentos corporales en mujeres mayores. 258 mujeres mayores (66,58±5,6años; 65,6±11,7kg; 1,53±0,07m fueron someter a la evaluación del pico de torque (PT en el dinamómetro (Biodex y de la MM (DXA. Correlaciones de Pearson se realizó entre la MM de los brazos, piernas, tronco, el cuerpo entero, de la pierna dominante (MMB, MMPs, MMT, MMCI, MMPD, respectivamente con el PT. La MM de todas regiones examinadas presentaron correlación positiva y significante con los valores del PT (pThe purpose of the present study was to correlate knee extensors muscle strength with fat-free mass (FFM of different body sites in older women. Peak torque (PT from 258 women (66.58±5.6years; 65.6±11.7kg; 1.53±0.07m was assessed using an isokinetic dynamometer (Biodex and FFM was evaluated using dual-energy x-ray absorptiometry (DXA. Pearson correlations were performed between FFM from Arms, Legs, Thorax, Whole Body and Dominant Leg (FFMA, FFMLs, FFMT, FFMWB and FFMDL, respectively with PT. Significance level was set at α <0.05 for all comparisons. Positive and significant correlations were observed between FFM from all sites and isokinetic PT (p<0.001. However, it was stronger when the site of FFM analyzed was closer to the muscle responsible to
Dolezal, Samantha M; Frese, Derek L; Llewellyn, Tamra L
The purpose of this study was to determine if combining velocity-based training with eccentric focus (VEB) and velocity-based training (VBT) results in power and strength gains. Nineteen men and women collegiate track and field athletes participated in this study. The subjects completed a 12-week intervention with either a VEB program or a VBT program. To determine the effectiveness of each program, the subjects completed four exercise tests before and after the training period: vertical jump, medicine ball put test, 1RM projected bench press and 1RM projected squat. There were no significant differences between the VBT results and the VEB results. However, there were significant improvements between the pre-test and post-test measures for each group. There were increases in 1RM projected squat for VEB men, VBT men, and VBT women. There were also significant improvements in the VEB male vertical jump and medicine ball put test pre- to post-intervention. For track and field athletes, both programs may result in strength and power gains, however, the results cannot be used to conclude that one resistance training program is superior.
Delextrat, Anne; Cohen, Daniel
The aim of the present study was to investigate the effect of playing position on strength, power, speed, and agility performances of women basketball players. Thirty subjects playing at national level participated in this study. They were divided into 3 groups according to playing position: guards (positions 1 and 2), forwards (positions 3 and 4), and centers (position 5). Each subject performed 8 tests presented in a random order: The 30-second Wingate Anaerobic test (WAnT), isokinetic testing of the knee extensors, 2 types of jump tests, a 20-m sprint, the agility T-test, a suicide run, and a basketball chest pass. Statistical differences between playing positions were assessed using a 1-way analysis of variance (ANOVA) and Scheffe post hoc analyses. Results showed that guards performed significantly better than centers for the relative peak and mean power achieved during the WAnT (+13% and +16.9%, respectively), relative peak torque of knee extensors (+19.5%), single-leg jump (+21.8), suicide run (+7.5%), and agility T-test (+6.4%, p training must be undertaken according to playing position. The ability to perform the suicide run, the single-leg jump, and the different movements involved in the agility T-test must be developed in guards. In contrast, speed over short distances and strength development of lower body and upper body should be performed by all playing positions.
Brightman, M.; Harrison, F. A.; Fürst, F.; Middleton, M. J.; Walton, D. J.; Stern, D.; Fabian, A. C.; Heida, M.; Barret, D.; Bachetti, M.
Ultraluminous X-ray sources (ULXs) are bright X-ray sources in nearby galaxies not associated with the central supermassive black hole. Their luminosities imply they are powered by either an extreme accretion rate onto a compact stellar remnant, or an intermediate mass ( 100-105M⊙) black hole1. Recently detected coherent pulsations coming from three bright ULXs2-5 demonstrate that some of these sources are powered by accretion onto a neutron star, implying accretion rates significantly in excess of the Eddington limit, a high degree of geometric beaming, or both. The physical challenges associated with the high implied accretion rates can be mitigated if the neutron star surface field is very high (1014 G)6, since this suppresses the electron scattering cross-section, reducing the radiation pressure that chokes off accretion for high luminosities. Surface magnetic field strengths can be determined through cyclotron resonance scattering features7,8 produced by the transition of charged particles between quantized Landau levels. Here, we present the detection at a significance of 3.8σ of an absorption line at 4.5 keV in the Chandra spectrum of a ULX in M51. This feature is likely to be a cyclotron resonance scattering feature produced by the strong magnetic field of a neutron star. Assuming scattering off electrons, the magnetic field strength is implied to be 1011 G, while protons would imply a magnetic field of B 1015 G.
Full Text Available The aim of this study was to evaluate the effectiveness of free-weight and machine-based exercises to increase different strength and speed-strength variables. One hundred twenty male participants (age: 23.8 ± 2.5 years; body height: 181.0 ± 6.8 cm; body mass: 80.2 ± 8.9 kg joined the study. The 2 experimental groups completed an 8 week periodized strength training program that included 2 training sessions per week. The exercises that were used in the strength training programs were the parallel barbell squat and the leg press. Before and after the training period, the 1-repetition-maximum in the barbell squat and the leg press, the squat jump, the countermovement jump and unilateral isometric force (maximal isometric force and the rate of force development were evaluated. To compare each group pre vs. post-intervention, analysis of variance with repeated measures and Scheffé post-hoc tests were used. The leg press group increased their 1-repetition-maximum significantly (p < 0.001, while in the squat group such variables as 1-repetition-maximum, the squat jump and the countermovement jump increased significantly (p < 0.001. The maximal isometric force showed no statistically significant result for the repeated measures factor, while the rate of force development of the squat group even showed a statistically significant decrease. Differences between the 2 experimental groups were detected for the squat jump and the countermovement jump. In comparison with the leg press, the squat might be a better strength training exercise for the development of jump performance.
Full Text Available Background: Hamstring injury is a common problem in many sports, especially those involving acceleration and maximal sprints. Hamstring strains are both common and painful. During sprinting the hip flexor and knee extensor torques are frequently produced and is opposed by the hamstring muscles, hence there are numerous studies done on the muscle strength training to prevent the hamstring strain injury as it is statistically stated as the highest rate involved injury in the contact sport. This study has been focused to evaluate the effectiveness of concentric and eccentric exercises in improving hamstring muscle strength and power among futsal players. Method: Thirty recreational futsal players were recruited for the study and were randomly divided into two groups. Each group received either hamstring curl exercise (concentric or Nordic hamstring exercise (eccentric twice a week for 4 weeks. The manual muscle test (MMT and 40-yard dash test was used to evaluate the muscle strength and power respectively by comparing the pretest and posttest values for both groups. Results: Wilcoxon signed rank test showed that there is no statistically significant difference between pre and post test values of MMT (Concentric (right side, z=.317; left side, z=.157, Eccentric (right side, z=.157; left side, z=.317 in both groups. Based on paired 't' test there is a significant difference between the pre and post test on improving muscle power [Concentric group, P=.020; Eccentric Group, P=.000]. Mann–Whitney U test and unpaired 't' test showed that there is no significant difference between both groups of MMT (z=.775 and 40-yard dash test (P=.707 respectively. Conclusion: The concentric strength training and eccentric strength training have a similar effect in improving hamstring muscle power in futsal players.
Sim, Young-Je; Byun, Yong-Hyun; Yoo, Jaehyun
[Purpose] The purpose of this study was to clarify the influence of static stretching at warm-up on the isokinetic muscle torque (at 60°/sec) and muscle power (at 180°/sec) of the flexor muscle and extensor muscle of the knee joint. [Subjects and Methods] The subjects of this study were 10 healthy students with no medically specific findings. The warm-up group and warm-up with stretching group performed their respective warm-up prior to the isokinetic muscle torque evaluation of the knee joint. One-way ANOVA was performed by randomized block design for each variable. [Results] The results were as follows: First, the flexor peak torque and extensor peak torque of the knee joint tended to decrease at 60°/sec in the warm-up with stretching group compared with the control group and warm-up group, but without statistical significance. Second, extensor power at 180°/sec was also not statistically significant. However, it was found that flexor power increased significantly in the warm-up with stretching group at 180°/sec compared with the control group and warm-up group in which stretching was not performed. [Conclusion] Therefore, it is considered that in healthy adults, warm-up including two sets of stretching for 20 seconds per muscle group does not decrease muscle strength and muscle power.
A mouse anti-myostatin antibody increases muscle mass and improves muscle strength and contractility in the mdx mouse model of Duchenne muscular dystrophy and its humanized equivalent, domagrozumab (PF-06252616), increases muscle volume in cynomolgus monkeys.
St Andre, Michael; Johnson, Mark; Bansal, Prashant N; Wellen, Jeremy; Robertson, Andrew; Opsahl, Alan; Burch, Peter M; Bialek, Peter; Morris, Carl; Owens, Jane
The treatments currently approved for Duchenne muscular dystrophy (DMD), a progressive skeletal muscle wasting disease, address the needs of only a small proportion of patients resulting in an urgent need for therapies that benefit all patients regardless of the underlying mutation. Myostatin is a member of the transforming growth factor-β (TGF-β) family of ligands and is a negative regulator of skeletal muscle mass. Loss of myostatin has been shown to increase muscle mass and improve muscle function in both normal and dystrophic mice. Therefore, myostatin blockade via a specific antibody could ameliorate the muscle weakness in DMD patients by increasing skeletal muscle mass and function, thereby reducing patients' functional decline. A murine anti-myostatin antibody, mRK35, and its humanized analog, domagrozumab, were developed and their ability to inhibit several TGB-β ligands was measured using a cell-based Smad-activity reporter system. Normal and mdx mice were treated with mRK35 to examine the antibody's effect on body weight, lean mass, muscle weights, grip strength, ex vivo force production, and fiber size. The humanized analog (domagrozumab) was tested in non-human primates (NHPs) for changes in skeletal muscle mass and volume as well as target engagement via modulation of circulating myostatin. Both the murine and human antibodies are specific and potent inhibitors of myostatin and GDF11. mRK35 is able to increase body weight, lean mass, and muscle weights in normal mice. In mdx mice, mRK35 significantly increased body weight, muscle weights, grip strength, and ex vivo force production in the extensor digitorum longus (EDL) muscle. Further, tibialis anterior (TA) fiber size was significantly increased. NHPs treated with domagrozumab demonstrated a dose-dependent increase in lean mass and muscle volume and exhibited increased circulating levels of myostatin demonstrating target engagement. We demonstrated that the potent anti-myostatin antibody mRK35 and
Saidj, Madina; Jørgensen, Torben; Jacobsen, Rikke K
associations' between sitting time and cardiorespiratory and muscular fitness among adults. The aim of the present study was to examine associations between work- and leisure-time sitting, and key markers of cardiorespiratory and muscular fitness among working adults. METHODS: Working adults (N=2544) aged 18......-69 from Health2006, a Danish population-based study, were included in this cross-sectional study. Sitting time during work and leisure time along with sociodemographic and behavioral covariates, including physical activity, were self-reported. Participants underwent a health examination with assessment...... of cardiorespiratory fitness (step test estimated VO 2Max, systolic and diastolic blood pressure) and muscular fitness (handgrip strength, lower limb extension power). Associations were explored by linear regression. Results Leisure-time sitting time was significantly (P
Berthelsen, Martin Peter; Husu, Edith; Christensen, Sofie Bouschinger
of their weakness. We investigated the functional effects of combined aerobic and strength training in patients with Becker and limb-girdle muscular dystrophies with knee muscle strength levels as low as 3% of normal strength. Eight patients performed 10weeks of aerobic and strength training on an anti...... affected patients with Becker and limb-girdle muscular dystrophies.......Recent studies in patients with muscular dystrophies suggest positive effects of aerobic and strength training. These studies focused training on using bicycle ergometers and conventional strength training, which precludes more severely affected patients from participating, because...
... as ALS (Lou Gehrig’s Disease), cystic fibrosis and Duchenne muscular dystrophy. Approximately 1 in 50 Americans, or about 6 ... Pediatric Neuromuscular Clinical Research Network ( PNCR ) and the Muscular ... is the SMN2 gene? Muscle weakness and atrophy in SMA results from the ...
Ian Gee Thomas
Full Text Available This study aimed to determine the effects of a short-term, strength training intervention, typically undertaken by club-standard rowers, on 2,000 m rowing performance and strength and power development. Twenty-eight male rowers were randomly assigned to intervention or control groups. All participants performed baseline testing involving assessments of muscle soreness, creatine kinase activity (CK, maximal voluntary contraction (leg-extensors (MVC, static-squat jumps (SSJ, counter-movement jumps (CMJ, maximal rowing power strokes (PS and a 2,000 m rowing ergometer time-trial (2,000 m with accompanying respiratory-exchange and electromyography (EMG analysis. Intervention group participants subsequently performed three identical strength training (ST sessions, in the space of five days, repeating all assessments 24 h following the final ST. The control group completed the same testing procedure but with no ST. Following ST, the intervention group experienced significant elevations in soreness and CK activity, and decrements in MVC, SSJ, CMJ and PS (p < 0.01. However, 2,000 m rowing performance, pacing strategy and gas exchange were unchanged across trials in either condition. Following ST, significant increases occurred for EMG (p < 0.05, and there were non-significant trends for decreased blood lactate and anaerobic energy liberation (p = 0.063 – 0.086. In summary, club-standard rowers, following an intensive period of strength training, maintained their 2,000 m rowing performance despite suffering symptoms of muscle damage and disruption to muscle function. This disruption likely reflected the presence of acute residual fatigue, potentially in type II muscle fibres as strength and power development were affected.
Johnston, Mark D. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Patel, Sonal G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Falcon, Ross Edward [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Cartwright, Keith [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Kiefer, Mark L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Cuneo, Michael E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States). Advanced Radiographic Technologies Dept.; Maron, Yitzhak [Weizmann Inst. of Science, Rehovot (Israel)
This LDRD investigated plasma formation, field strength, and current loss in pulsed power diodes. In particular the Self-Magnetic Pinch (SMP) e-beam diode was studied on the RITS-6 accelerator. Magnetic fields of a few Tesla and electric fields of several MV/cm were measured using visible spectroscopy techniques. The magnetic field measurements were then used to determine the current distribution in the diode. This distribution showed that significant beam current extends radially beyond the few millimeter x-ray focal spot diameter. Additionally, shielding of the magnetic field due to dense electrode surface plasmas was observed, quantified, and found to be consistent with the calculated Spitzer resistivity. In addition to the work on RITS, measurements were also made on the Z-machine looking to quantify plasmas within the power flow regions. Measurements were taken in the post-hole convolute and final feed gap regions on Z. Dopants were applied to power flow surfaces and measured spectroscopically. These measurements gave species and density/temperature estimates. Preliminary B-field measurements in the load region were attempted as well. Finally, simulation work using the EMPHASIS, electromagnetic particle in cell code, was conducted using the Z MITL conditions. The purpose of these simulations was to investigate several surface plasma generations models under Z conditions for comparison with experimental data.
Read, Paul J; Lloyd, Rhodri S; De Ste Croix, Mark; Oliver, Jon L
Increased golf club head speed (CHS) has been shown to result in greater driving distances and is also correlated with golf handicap. The purpose of this study was to investigate the relationships between field-based measures of strength and power and golf CHS with a secondary aim to determine the reliability of the selected tests. A correlation design was used to assess the following variables: anthropometrics, squat jump (SJ) height and squat jump peak power (SJPP), unilateral countermovement jump (CMJ) heights (right leg countermovement jump and left leg countermovement jump [LLCMJ]), bilateral CMJ heights, countermovement jump peak power (CMJPP), and medicine ball seated throw (MBST) and medicine ball rotational throw (MBRT). Fouty-eight male subjects participated in the study (age: 20.1 ± 3.2 years, height: 1.76 ± 0.07 m, mass: 72.8 ± 7.8 kg, handicap: 5.8 ± 2.2). Moderate significant correlations were reported between CHS and MBRT (r = 0.67; p golf athletes using the proposed battery of field tests. Additionally, movements that are more concentrically dominant in nature may display stronger relationships with CHS due to MBST and SJ displaying the highest explained variance after a stepwise linear regression.
Regterschot, G Ruben H; Folkersma, Marjanne; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren
Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS peak power and related measures are sensitive to the effects of increasing leg strength, leg power and overall balance in older adults. A further aim was to compare sensitivity between sensor-based STS measures and standard clinical measures of leg strength, leg power, balance, mobility and fall risk, following an exercise-based intervention. To achieve these aims, 26 older adults (age: 70-84 years) participated in an eight-week exercise program aimed at improving leg strength, leg power and balance. Before and after the intervention, performance on normal and fast STS transfers was evaluated with a hybrid motion sensor worn on the hip. In addition, standard clinical tests (isometric quadriceps strength, Timed Up and Go test, Berg Balance Scale) were performed. Standard clinical tests as well as sensor-based measures of peak power, maximal velocity and duration of normal and fast STS showed significant improvements. Sensor-based measurement of peak power, maximal velocity and duration of normal STS demonstrated a higher sensitivity (absolute standardized response mean (SRM): ≥ 0.69) to the effects of training leg strength, leg power and balance than standard clinical measures (absolute SRM: ≤ 0.61). Therefore, the presented sensor-based method appears to be useful for detecting changes in mobility and fall risk. Copyright © 2013 Elsevier B.V. All rights reserved.
Rhea Matthew R.
Full Text Available Purpose. The purpose of this study was to examine the influence of training at different ranges of motion during the squat exercise on joint-angle specific strength adaptations. Methods. Twenty eight men were randomly assigned to one of three training groups, differing only in the depth of squats (quarter squat, half squat, and full squat performed in 16-week training intervention. Strength measures were conducted in the back squat pre-, mid-, and post-training at all three depths. Vertical jump and 40-yard sprint time were also measured. Results. Individuals in the quarter and full squat training groups improved significantly more at the specific depth at which they trained when compared to the other two groups (p < 0.05. Jump height and sprint speed improved in all groups (p < 0.05; however, the quarter squat had the greatest transfer to both outcomes. Conclusions. Consistently including quarter squats in workouts aimed at maximizing speed and jumping power can result in greater improvements.
Regterschot, G Ruben H; Folkersma, Marjanne; Zhang, Wei; Baldus, Heribert; Stevens, Martin; Zijlstra, Wiebren
Increasing leg strength, leg power and overall balance can improve mobility and reduce fall risk. Sensor-based assessment of peak power during the sit-to-stand (STS) transfer may be useful for detecting changes in mobility and fall risk. Therefore, this study investigated whether sensor-based STS
Fahs, Christopher A; Rossow, Lindy M; Thiebaud, Robert S; Loenneke, Jeremy P; Kim, Daeyeol; Bemben, Michael G; Abe, Takashi
Unilateral physical training can enhance muscular size and function as well as vascular function in the trained limb. In non-athletes, the preferred arm for use during unilateral tasks may exhibit greater muscular strength compared to the non-preferred arm. It is unclear if lower limb preference affects lower limb vascular function or muscular endurance and power in recreationally active adults. To examine the effect of lower limb preference on quadriceps muscle size and function and on lower limb vascular function in middle-aged adults. Twenty (13 men, 7 women) recreationally-active middle-aged (55 ± 7 yrs) adults underwent measurements of quadriceps muscle thickness, strength, mean power, endurance, and arterial stiffness, calf venous compliance, and calf blood flow in the preferred and non-preferred lower limb. The preferred limb exhibited greater calf vascular conductance (31.6 ± 15.5 versus 25.8 ± 13.0 units flow/mmHg; p = 0.011) compared to the non-preferred limb. The interlimb difference in calf vascular conductance was negatively related to weekly aerobic activity (hrs/week) (r = −0.521; p = 0.019). Lower limb preference affects calf blood flow but not quadriceps muscle size or function. Studies involving unilateral lower limb testing procedures in middle-aged individuals should consider standardizing the testing to either the preferred or non-preferred limb rather than the right or left limb. (paper)
Função muscular esquelética e composição corporal de pacientes com hipertireoidismo submetidos ao treinamento contra resistência Skeletal muscle performance and body composition of patients with hyperthyroidism submitted to strength training
Kelb Bousquet Santos
Full Text Available O hipertireoidismo está associado a uma fraqueza muscular generalizada que é parte da manifestação clínica inicial de cerca de 80% dos pacientes. A recuperação da performance muscular esquelética durante o tratamento do hipertireoidismo depende tanto do aumento da massa muscular quanto da melhoria da função intrínseca da musculatura esquelética. Por outro lado, o treinamento contra resistência aumenta a força e a endurance muscular em diferentes grupos de indivíduos. O objetivo do presente trabalho foi avaliar o efeito deste tipo de treinamento sobre a recuperação da função muscular esquelética de pacientes portadores de hipertireoidismo. Os pacientes, atendidos no ambulatório de endocrinologia, diagnosticados clínica e laboratorialmente com doença de Graves, foram submetidos, antes do tratamento e quatro meses após, a medidas antropométricas e testes de força máxima e endurance musculares (sustentando 30% da carga máxima de quatro movimentos [handgrip esquerdo (HE e direito (HD, legpress (LEG, flexão plantar de tornozelo (FPT e supino reto (SR]. Após a avaliação inicial, os pacientes foram divididos em dois grupos: 1 controle (GC - tratamento medicamentoso e 2 treinamento (GT - acrescentado treinamento contra resistência individualizado 2X/semana. Os resultados (GC, n = 3; GT, n = 4; todas do sexo feminino mostram: Os autores concluem que o treinamento contra resistência parece favorecer aumento da massa e da performance muscular esquelética em pacientes com hipertireoidismo.Hyperthyroidism is associated with a general muscle weakness, which is part of the initial clinical manifestation of about 80% of patients. The recovery of skeletal muscle performance during hyperthyroidism treatment depends on both greater muscle mass and improved muscle function. Strength training is an effective method to improve muscle strength and endurance. The purpose of this study was to evaluate the effect of this type of training
Full Text Available BACKGROUND: Effective execution of vertical jump depends on the explosive power of lower limbs and their symmetrical integration mainly. Assessment of lower extremity bilateral asymmetries in soccer players is important for both injury prevention and performance. OBJECTIVE: The aim of this study was to identify and compare parameters of lower limb power in three different jump tests in elite soccer goalkeepers. The next aim was to describe and compare strength asymmetries of force exerted by lower limbs in the take-off phase in all tests. METHOD: The research group consisted of 25 elite soccer goalkeepers (age 26.5 ± 9.1 years, height 186.1 ± 7.8 cm, weight 86.7 ± 14.8 kg. Three types of a vertical jump – countermovement jump with arms included (CMJFA, countermovement jump with arms excluded (CMJ and squat jump (SJ were performed on two force platforms. Following parameters were assessed – maximum force during the take-off phase Fmax (N and their relative value Frel (N • kg–1, jump height h (m and force asymmetry between limbs (∆Fmax. RM ANOVA was used in statistical analysis. RESULTS: The type of jump had a significant effect on jump height (F2, 48 = 109.66, p < .01, η2 = .82. The highest jump was reached in CMJFA. This result was higher by 11.1% (5.01 cm in comparison to CMJ and by 19.9% (8.98 cm than in SJ. Type of jump significantly influenced Fmax (F1.6, 38.7 = 44.29, p < .01, η2 = .65 and Frel (F2, 48 = 50.33, p < .01, η2 = .68. Force asymmetry between limbs (∆Fmax was significantly different with respect to the type of jump performed (F1.3, 31.7 = 5.14, p < .05, η2 = .18. The highest force asymmetry was found in CMJFA test (∆Fmax = 8.61%, while the difference in CMJ test was (7.06% and in SJ test (∆Fmax = 3.95%. We found a significantly greater difference in ∆Fmax between CMJFA vs. SJ (p < .05 and CMJ vs. SJ (p < .01
Lopes, Paula Born; Pereira, Gleber; Lodovico, Angélica; Bento, Paulo C B; Rodacki, André L F
It has been proposed that muscle power is more effective to prevent falls than muscle force production capacity, as rapid reactions are required to allow the postural control. This study aimed to compare the effects of strength and power training on lower limb force, functional capacity, and static and dynamic balance in older female adults. Thirty-seven volunteered healthy women had been allocated into the strength-training group (n = 14; 69 ± 7.3 years, 155 ± 5.6 cm, 72 ± 9.7 kg), the power-training group (n = 12; 67 ± 7.4 years, 153 ± 5.5 cm, 67.2 ± 7 kg), and control group (n = 11; 65 ± 3.1 years, 154 ± 5.6 cm, 70.9 ± 3 kg). After 12 weeks of training, the strength-training and power-training groups increased significantly maximum dynamic strength (29% and 27%), isometric strength (26% and 37%), and step total time (13% and 14%, dynamic balance), respectively. However, only the power-training group increased the rate of torque development (55%) and the functional capacity in 30-second chair stand (22%) and in time up and go tests (-10%). Empirically, power training may reduce the risk of injuries due to lower loads compared to strength training, and consequently, the physical effort demand during the training session is lower. Therefore, power training should be recommended as attractive training stimuli to improve lower limb force, functional capacity, and postural control of older female adults.
Jenkins, Nathaniel D M; Housh, Terry J; Palmer, Ty B; Cochrane, Kristen C; Bergstrom, Haley C; Johnson, Glen O; Schmidt, Richard J; Cramer, Joel T
We compared absolute and normalized values for peak torque (PT), mean power (MP), rate of velocity development, and electromyography (EMG) amplitude during maximal isometric and concentric isokinetic leg extension muscle actions, as well as the %decrease in PT and %increase in MP from 1.05 to 3.14 rad·s(-1) in younger versus older men. Measurements were performed twice for reliability. Isokinetic measurements were normalized to the isometric muscle actions. Absolute isometric PT, isokinetic PT and MP, and EMG amplitudes at 1.05 and 3.14 rad·s(-1) were greater in the younger men, although normalizing to isometric PT eliminated the age differences. The older men exhibited greater %decrease in PT (37.2% vs. 31.3%) and lower %increase in MP (87.6% vs. 126.4%) regardless of normalization. Normalization eliminated absolute differences in isokinetic strength and power, but the relative differences from slow to fast velocities may reflect dynapenia characterized by age-related decreases in fast-twitch fiber function. © 2014 Wiley Periodicals, Inc.
Bieler, Theresa; Magnusson, S Peter; Kjær, Michael
OBJECTIVE: To investigate the reliability and agreement of measures of lower extremity muscle strength, power and functional performance in patients with hip osteoarthritis at different time intervals, and to compare these with the same measures in healthy peers. DESIGN: Intra-rater test...... extensor power, and functional performance (8-foot Up & Go, stair climbing, chair stand and 6-min walk) were measured in patients, and quadriceps strength, leg extensor power and functional performance were measured in healthy peers. Systematic error, reliability and agreement were calculated. RESULTS......-retest separated by 1, 2, or 2.5 weeks in patients, and 1 week in healthy peers. SUBJECTS: Patients with hip osteoarthritis (age range 61-83 years) with 1 (n = 37), 2 (n = 35), or 2.5 weeks (n = 15) between tests, and 35 healthy peers (age range 63-82 years). METHODS: Maximal isometric hip and thigh strength, leg...
Rivière, Maxence; Louit, Loic; Strokosch, Alasdair; Seitz, Laurent B
Rivière, M, Louit, L, Strokosch, A, and Seitz, LB. Variable resistance training promotes greater strength and power adaptations than traditional resistance training in elite youth rugby league players. J Strength Cond Res 31(4): 947-955, 2017-The purpose of this study was to examine the strength, velocity, and power adaptations in youth rugby league players in response to a variable resistance training (VRT) or traditional free-weight resistance training (TRAD) intervention. Sixteen elite youth players were assigned to a VRT or TRAD group and completed 2 weekly upper- and lower-body strength and power sessions for 6 weeks. Training programs were identical except that the VRT group trained the bench press exercise with 20% of the prescribed load coming from elastic bands. Bench press 1 repetition maximum (1RM) and bench press mean velocity and power at 35, 45, 65, 75, and 85% of 1RM were measured before and after the training intervention, and the magnitude of the changes was determined using effect sizes (ESs). The VRT group experienced larger increases in both absolute (ES = 0.46 vs. 0.20) and relative (ES = 0.41 vs. 0.19) bench press 1RM. Similar results were observed for mean velocity as well as both absolute and relative mean power at 35, 45, 65, 75, and 85% of 1RM. Furthermore, both groups experienced large gains in both velocity and power in the heavier loads but small improvements in the lighter loads. The improvements in both velocity and power against the heavier loads were larger for the VRT group, whereas smaller differences existed between the 2 groups in the lighter loads. Variable resistance training using elastic bands may offer a greater training stimulus than traditional free-weight resistance training to improve upper-body strength, velocity, and power in elite youth rugby league players.
El trabajo de fuerza en el desarrollo de la potencia en futbolistas de las divisiones menores de un equipo profesional de fútbol Strength training in the development of power in soccer players of the inferior divisions of Deportivo Independiente Medellin (DIM, in Colombia
Carlos Adolfo Castro Castro
flexores de la rodilla derecha, fuerza de los flexores de la rodilla izquierda, Squat Jump y Countermovement Jump - hubo incrementos estadísticamente significativos (p < 0.05 en cada grupo tanto a las 6 semanas como entre las 6 y las 12 semanas: se exceptuó la velocidad en 20 metros que sólo presentó aumento significativo a las 6 semanas. Para ambos grupos, las correlaciones (r de Pearson de la fuerza máxima (FM de los extensores de la rodilla derecha con el SJ y el CMJ fueron de moderadas a fuertes y estadísticamente significativas (p < 0.05 tanto al inicio del estudio como a las 6 y a las 12 semanas de entrenamiento de FM; la correlación con la velocidad en 20 metros se halló sólo al inicio del trabajo. Conclusión: el trabajo de FM en intensidades al 75 y 85% de 1-RM produce mejorías significativas en la potencia muscular inmediata. Theoretically, high levels of strength correlate with improvement in manifestations of immediate muscular power, which is a decisive variable of performance in modern soccer. Purpose: to determine in soccer players if strength training at a high percentage (85% of 1-RM, looking for increase in maximum strength, is more effective in improving immediate muscular power than a similar training but at 75% of 1-RM. Methodology: 60 soccer players belonging to the inferior divisions of DIM were randomly assigned to either one of two groups of 30 players each, and performed the following strength training protocols: the experimental group carried out an individual bilateral force training for knee extensors and flexors that consisted of 3 series of 5 repetitions each, at 85% of 1-RM, with 5 minutes of rest between series, twice a week during 12 weeks. The control group trained the same muscular groups, 3 series of 8 repetitionseach, at 75% of 1-RM, also with 5 minutes of rest between series, twice a week during 12 weeks. At the onset, and at 6 and 12 weeks measurements were made of maximum strength (1-RM of knee extensors and flexors and of
... patients may need assisted ventilation to treat respiratory muscle weakness and a pacemaker for cardiac abnormalities. View Full Treatment Information Definition The muscular dystrophies (MD) are a group of more than 30 ...
... There is no known cure for facioscapulohumeral muscular dystrophy. Treatments are given to control symptoms and improve quality of life. Activity is encouraged. Inactivity such as bedrest can make the muscle disease worse. Physical therapy may help maintain muscle ...
Lahoria, Rajat; Milone, Margherita
Rhabdomyolysis is a potentially life threatening condition of various etiology. The association between rhabdomyolysis and muscular dystrophies is under-recognized in clinical practice. To identify muscular dystrophies presenting with rhabdomyolysis at onset or as predominant feature. We retrospectively reviewed clinical and laboratory data of patients with a genetically confirmed muscular dystrophy in whom rhabdomyolysis was the presenting or main clinical manifestation. Thirteen unrelated patients (males=6; females=7) were identified. Median age at time of rhabdomyolysis was 18 years (range, 2-47) and median duration between the first episode of rhabdomyolysis and molecular diagnosis was 2 years. Fukutin-related protein (FKRP) muscular dystrophy (n=6) was the most common diagnosis, followed by anoctaminopathy-5 (n=3), calpainopathy-3 (n=2) and dystrophinopathy (n=2). Four patients experienced recurrent rhabdomyolysis. Eight patients were asymptomatic and 3 reported myalgia and exercise intolerance prior to the rhabdomyolysis. Exercise (n=6) and fever (n=4) were common triggers; rhabdomyolysis was unprovoked in 3 patients. Twelve patients required hospitalization. Baseline CK levels were elevated in all patients (median 1200 IU/L; range, 600-3600). Muscular dystrophies can present with rhabdomyolysis; FKRP mutations are particularly frequent in causing such complication. A persistently elevated CK level in patients with rhabdomyolysis warrants consideration for underlying muscular dystrophy. Copyright © 2015 Elsevier B.V. All rights reserved.
Behm, David G; Muehlbauer, Thomas; Kibele, Armin; Granacher, Urs
The effectiveness of strength training on unstable surfaces (STU) versus stable surfaces (STS) or a control condition (CON; i.e., no training or regular training only) for strength, power and balance performance across the lifespan has not yet been investigated in a systematic review and meta-analysis. The aims of this systematic review and meta-analysis were to determine the general effects of STU versus STS or CON on muscle strength, power and balance in healthy individuals across the lifespan and to investigate whether performance changes following STU are age specific. A computerized systematic literature search was performed in the electronic databases PubMed and Web of Science from January 1984 up to February 2015. Initially, 209 articles were identified for review. Only controlled trials were included if they investigated STU in healthy individuals and tested at least one measure of maximal strength, strength endurance, muscle power, or static/dynamic balance. In total, 22 studies met the inclusion criteria. The included studies were coded for the following criteria: age, sex, training status, training modality, exercise and test modality. Effect size measures included within-subject standardized mean differences (SMDw) and weighted between-subject standardized mean differences (SMDb). Heterogeneity between studies was assessed using I2 and χ2 statistics. The methodological quality of each study was assessed using the Physiotherapy Evidence Database (PEDro) Scale. Our search failed to identify studies that examined the effects of STU versus STS or CON in children and middle-aged adults. However, four studies were identified that investigated the effects of STU versus CON or STS in adolescents, 15 studies were identified in young adults and three studies were identified in old adults. Compared with CON, STU produced medium effects on maximal strength in young adults and no effects to medium effects in old adults. In addition, large effects were detected on
Full Text Available Com o envelhecimento há rápida e relevante perda de potência muscular (PM, prejudicando a autonomia e a qualidade de vida, tornando conveniente avaliar a PM. O objetivo do estudo foi determinar a fidedignidade inter e intradias de um teste simples de PM, realizado em uma carga previamente individualizada. Avaliamos 18 jovens adultos saudáveis, sendo 12 mulheres, inexperientes quanto a exercícios de fortalecimento. Determinou-se inicialmente 1RM com medida simultânea da velocidade e da potência (Fitrodyne, Bratislava, no exercício remada alta, até a altura mesoesternal na posição ortostática, obtendo-se ainda a carga na qual se conseguia a maior PM. Na semana seguinte, por cinco dias consecutivos, eles realizaram em quatro dias 2x2 repetições e em um dia 10x2 repetições (3s de intervalo entre as repetições, o mais rápido possível na fase concêntrica, com a carga de PM. Comparando os resultados pela ANOVA para medidas repetidas e teste de Bonferroni, verificou-se que a PM máxima não diferia - médias entre 262 e 267W (p = 0,69. Para a variabilidade dos dados individuais, encontraram-se valores de 3 e 8%, respectivamente, para o coeficiente de variação (CV e para a média da variação dos resultados pela média dos indivíduos M-m/X. Nas dez séries consecutivas os valores ficaram entre 242 e 263W, somente identificando-se diferenças entre as séries 1 e 4 e 6 (p Aging induces fast and relevant decrements in muscle power (MP, reducing autonomy and quality of life. The authors' aim was to determine reliability data in a new, simple protocol for muscle power using a previously individualized load. The authors evaluated 18 healthy young adults (12 women, unaccustomed to strengthening exercises. Initially, 1-RM was determined with simultaneous measurement of velocity and MP (Fitrodyne, Bratislava in an upright row exercise, performed up to mesosternal level in standing position, and measurement of load in which MP was
Granacher, Urs; Gollhofer, Albert; Hortobagyi, Tibor; Kressig, Reto W.; Muehlbauer, Thomas
Background The aging process results in a number of functional (e.g., deficits in balance and strength/power performance), neural (e.g., loss of sensory/motor neurons), muscular (e.g., atrophy of type-II muscle fibers in particular), and bone-related (e.g., osteoporosis) deteriorations.
Exercício aeróbico, treinamento de força muscular e testes de aptidão física para adolescentes com fibrose cística: revisão da literatura Exercise testing, aerobic and strength training for adolescents with cystic fibrosis: a literature review
Celia Regina Moutinho de Miranda Chaves
Full Text Available São reconhecidos os benefícios da prática do exercício físico regular para pacientes com fibrose cística. Entretanto, poucos estudos envolvem pacientes adolescentes. O objetivo deste artigo foi revisar os efeitos da prática regular de exercícios aeróbicos e de força e resistência muscular para adolescentes com fibrose cística. Os principais testes de aptidão física para esta faixa etária e a importância deles para melhora do prognóstico e tratamento da doença também foram avaliados. As informações foram coletadas a partir de livro-texto e artigos publicados na literatura nacional e estrangeira nas seguintes bases de dados: LILACS, MEDLINE/PubMed, Biblioteca Cochrane e SciELO, abrangendo o período de 1994 a 2004. Foram utilizados os termos "exercise" e "cystic fibrosis" para seleção dos artigos. Esta pesquisa demonstrou que a prática de exercício aeróbico e treinamento de força muscular melhoram a desobstrução da árvore brônquica, diminuem a queda progressiva da função pulmonar, aumentam a massa muscular e a resistência ao exercício, promovem o desenvolvimento ósseo e melhoram a auto-estima e a qualidade de vida. Os melhores resultados foram obtidos com os programas de treinamento assistido, devido a sua maior regularidade.The benefits of regular physical exercises for cystic fibrosis patients are well known. Nevertheless, few studies involve adolescent patients. The objective of this article was to review the effects of regular practice of aerobic exercises, strength exercises and muscular exercises in adolescents with cystic fibrosis. The main physical fitness tests for this age bracket and their value in improving prognosis and treatment were assessed as well. Information was collected from text books and articles published in the national and foreign literature in the following databases: LILACS, MEDLINE/PubMed, Cochrane Library and SciELO, comprising the period of 1994 to 2004. The terms "exercise" and
Full Text Available Purpose. Tests such as the counter movement jump (CMJ and squat jump (SJ allow for determining the ratio of maximal power output generated during SJ to CMJ (S/C. The isokinetic peak torque ratio of the hamstrings contracting eccentrically to the quadriceps contracting concentrically (H/Q is defined as functional H/Q. The purpose of this study was to compare the S/C and functional H/Q between female basketball and volleyball players. Methods. The total of 14 female basketball players (age, 19.8 ± 1.4 years and 12 female volleyball players (age, 22.3 ± 4.2 years participated in the study. A piezoelectric force platform was used for the CMJ and SJ. Moreover, isokinetic tests of the hamstrings and quadriceps muscle torque during eccentric and concentric contraction were performed. Results. The results of the S/C and functional H/Q at 90 deg · s-1/60 deg · s-1 velocities were higher in basketball players (87.3 ± 9.1% and 91.4 ± 9.3%, respectively than in volleyball players (83.1 ± 9.8% and 83.6 ± 16.5%, respectively. No significant differences in S/C or functional H/Q values between the two groups were found (p > 0.05. Conclusions. Decreasing the S/C may result from an improvement in the power output during CMJ and a better utilization of the stretch-shortening cycle effect. Balancing the functional H/Q through increasing the eccentric hamstrings strength can provide dynamic knee joint stabilization.
Verdan, Princess J R; Marzilli, Thomas S; Barna, Geanina I; Roquemore, Anntionette N; Fenter, Brad A; Blujus, Brittany; Gosselin, Kevin P
The purpose of this study was to determine the effect of Power Balance® bands on strength, flexibility, and balance. Strength and flexibility were measured using the MicroFit system. Strength was measured via a bicep curl and flexibility via the sit-and-reach method. Balance was measured by the BIODEX System SD. There were 4 different conditions for the balance test: eyes open on a firm surface (EOFS), eyes closed on a firm surface (ECFS), eyes open on a foam surface (EOFoS), and eyes closed on a foam surface (ECFoS). There were 24 subjects in the study (10 men and 14 women). A counterbalance, double-blind, placebo, controlled within-subject design was used. Each of the subjects participated in 3 treatment sessions, consisting of Power Balance®, placebo band, and no band. An alpha level of p ≤ 0.05 was set a priori. There were no significant differences in strength, flexibility, or balance with regard to the treatments used. There was a significant difference between the conditions in the balance test (p = 0.000): EOFS (0.51), ECFS (0.68), EOFoS (0.99), and ECFoS (2.18); however, these were independent of the treatment conditions. The results indicate that the Power Balance® bands did not have an effect on strength, flexibility, or balance.
Woolstenhulme, Mandy T; Bailey, Brooke Kerbs; Allsen, Philip E
We measured vertical jump, anaerobic power, and shooting accuracy in 18 Division I women basketball players (age 18-22 years) 6 hours following a morning strength training routine called a lift day (LD) and on a control day in which no strength training was performed. Subjects had been strength trained for 4 weeks prior to testing. The strength training session on lift day was a full-body workout and included 7 exercises performed in 3-6 sets at loads ranging from a 5 to 12 repetition maximum (RM). There were no significant differences in jump height with 2 legs (49.5 +/- 4.8 cm and 49.0 +/- 4.8 cm, LD and control, respectively), relative mean power output over 30 seconds on a Wingate bicycle test (6.4 +/- 0.8 W.kg(-1) and 6.6 +/- 0.7 W.kg(-1), LD and control, respectively), or shooting accuracy over 60 seconds (21.5 +/- 3.8 points/min and 21.3 +/- 4.1 points/min, LD and control, respectively). These data suggest that in collegiate women basketball players, a previous bout of strength training has no negative effect on vertical jump height, anaerobic power, or shooting accuracy.
Performance in strength and power sports is greatly affected by a variety of anthropometric factors. The goal of performance normalization is to factor out the effects of confounding factors and compute a canonical (normalized) performance measure from the observed absolute performance. Performance normalization is applied in the ranking of elite athletes, as well as in the early stages of youth talent selection. Consequently, it is crucial that the process is principled and fair. The corpus of previous work on this topic, which is significant, is uniform in the methodology adopted. Performance normalization is universally reduced to a regression task: the collected performance data are used to fit a regression function that is then used to scale future performances. The present article demonstrates that this approach is fundamentally flawed. It inherently creates a bias that unfairly penalizes athletes with certain allometric characteristics, and, by virtue of its adoption in the ranking and selection of elite athletes, propagates and strengthens this bias over time. The main flaws are shown to originate in the criteria for selecting the data used for regression, as well as in the manner in which the regression model is applied in normalization. This analysis brings into light the aforesaid methodological flaws and motivates further work on the development of principled methods, the foundations of which are also laid out in this work.
... with mental retardation Muscular dystrophy, congenital, Fukuyama type Muscular dystrophy, congenital, with central nervous system involvement Polymicrogyria with muscular dystrophy Related Information How ...
SUMMARY: This 3 year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of ...
Rafael Merino Marban, Daniel Mayorga Vega, Emilio Fernández Rodríguez, Francisco José Santana Pérez, Oscar Romero Ramos
Full Text Available Based on the body’s energy field, the inventors of Power Balance® have created a hologram that theoretically runs through frequencies that are in our natural environment. Its creators say that people may experience improve balance, strength, flexibility, endurance, concentration, coordination and recovery time, among others. The purpose of this research is to evaluate the effect of Power Balance® hologram on balance, flexibility, strength and speed-coordination in university students. A sample of 105 young volunteers’ physical education students (age 20.91 ± 3.36 years, mass 69.69 ± 11.35 kg, height 171.70 ± 8.07 cm was used. A between-group experimental design with double-blind control group was used to evaluate the possible effects of the Power Balance ® on the dynamic balance, flexibility, abdominal strength, endurance and speed-coordination measured with the Dynamic Balance Test, Sit and Reach, Sit-ups in 30 seconds and Race 10 x 5 m, respectively. A t of Student for independent and dependent samples was used to assess the potential effects between-group and intra-group, respectively. Power Balance®’s hologram produces no significant effects on the balance, flexibility, strength and speed-coordination among university students
De Groot, Sonja; Janssen, Thomas W. J.; Evers, Marijn; Van der Luijt, Pieter; Nienhuys, Kirsten N. G.; Dallmeijer, Annet J.
Aim The aim of this study was to analyse the feasibility and reliability of the tests used to determine muscle strength, sprint power, and aerobic capacity in athletes and non-athletes with cerebral palsy (CP). Methods Twenty individuals with spastic CP (four females, 16 males; age range 1849y;
Regterschot, G. Ruben H.; Morat, Tobias; Folkersma, Marjanne; Zijlstra, Wiebren
Leg muscle strength (LMS) and leg muscle power (LMP) are determinants of aspects of functional status and important parameters for measuring intervention effects in older adults. Field tests are often used for the evaluation of LMS and LMP in older persons. However, criteria important for the
de Groot, S.; Janssen, T.W.J.; Evers, M.; Van der Luijt, P.; Nienhuys, K.N.G.; Dallmeijer, A.J.
Aim The aim of this study was to analyse the feasibility and reliability of the tests used to determine muscle strength, sprint power, and aerobic capacity in athletes and non-athletes with cerebral palsy (CP). Methods Twenty individuals with spastic CP (four females, 16 males; age range 18-49y;
Awatani, Takenori; Morikita, Ikuhiro; Mori, Seigo; Shinohara, Junji; Tatsumi, Yasutaka
[Purpose] The purpose of the present study was to confirm the relationships between shoulder strength (extensor strength and internal rotator strength) of the abducted position and swimming power during arm-only swimming. [Subjects and Methods] Fourteen healthy male collegiate swimmers participated in the study. Main measures were shoulder strength (strength using torque that was calculated from the upper extremity length and the isometric force of the abducted position) and swimming power. [Results] Internal rotation torque of the dominant side in the abducted external rotated position (r=0.85) was significantly correlated with maximum swimming power. The rate of bilateral difference in extension torque in the maximum abducted position (r=-0.728) was significantly correlated with the swimming velocity-to-swimming power ratio. [Conclusion] The results of this study suggest that internal rotator strength measurement in the abducted external rotated position and extensor strength measurement in the maximum abducted position are valid assessment methods for swimmers.
Denise de Moraes Paisani
Full Text Available INTRODUÇÃO: A gastroplastia tem sido cada vez mais indicada no tratamento de obesos mórbidos, pacientes nos quais podemos identificar alteração pronunciada de volumes e capacidades pulmonares. OBJETIVO: Avaliar o comportamento dos volumes e capacidades pulmonares, força muscular respiratória, padrão respiratório e as possíveis complicações pulmonares pós-operatórias. MÉTODO: Vinte e um pacientes (três homens com média de idade de 39 ± 9,7 anos, média de índice de massa corpórea de 50,4 Kg/m², candidatos à gastroplastia, foram avaliados no pré-operatório, primeiro, terceiro e quinto dias de pós-operatório e submetidos a mensuração de volume corrente, capacidade vital, volume minuto, pressões máximas expiratória e inspiratória, e circunferências abdominal e torácica. Observou-se a ocorrência de complicações pulmonares pós-operatórias e mortalidade. RESULTADOS: No primeiro e terceiro dias de pós-operatório houve queda de 47% e 30,5% na capacidade vital, 18% e 12,5% no volume minuto, 28% e 21% no volume corrente, 47% e 32% no índice diafragmático, 51% e 26% na pressão inspiratória máxima, e 39,5% e 26% na pressão expiratória máxima, respectivamente (p BACKGROUND: Gastroplasty has been increasingly used in the treatment of morbidly obese patients, who typically present pronounced alterations in lung volume and capacity. OBJECTIVE: To evaluate post-gastroplasty lung volume, lung capacity, respiratory muscle strength and respiratory pattern, as well as any postoperative pulmonary complications. METHOD: 21 patients (3 of them men, with an average age of 39 ± 9.7 years and an average body mass index of 50.4 kg/m², all candidates for gastroplasty, were evaluated during the preoperative period and again on the first, third and fifth postoperative days. Tidal volume, vital capacity, minute volume, maximal expiratory pressure and maximal inspiratory pressure, as well as chest and waist circumferences, were
BROUWER, OF; PADBERG, GW; VANDERPLOEG, RJO; RUYS, CJM; BRAND, R
The strength of 10 muscle groups in both arms was measured using hand-held myometry to determine the influence of handedness on left-right differences of muscle strength in facioscapulohumeral muscular dystrophy (FSHD). Two groups of subjects were studied: 24 healthy volunteers (19 right-handed),
Sheila Seleri Marques Assunção
Full Text Available Preocupações mórbidas com a imagem corporal eram tidas até recentemente como problemas eminentemente femininos. Atualmente estas preocupações também têm sido encontradas no sexo masculino. A dismorfia muscular é um subtipo do transtorno dismórfico corporal que ocorre principalmente em homens que, apesar da grande hipertrofia muscular, consideram-se pequenos e fracos. Além de estar associada a prejuízos sociais, ocupacionais, recreativos e em outras áreas do funcionamento do indivíduo, a dismorfia muscular é também um fator de risco para o abuso de esteróides anabolizantes. Este artigo aborda aspectos epidemiológicos, etiológicos e padrões clínicos da dismorfia muscular, além de tecer comentários sobre estratégias de tratamento para este transtorno.Morbid concern over body image was considered, until recently, a female issue. Nowadays, it has been viewed as a common male disorder. Muscle dysmorphia, a subtype of a body dysmorphic disorder, affects men who, despite having clear muscular hypertroph,y see themselves as frail and small. Besides being associated to major social, leisure and occupational dysfunction, muscle dysmorphia is also a risk factor for the abuse of steroids. This article describes epidemiological, etiological and clinical characteristics of muscle dysmorphia and comments on its treatment strategy.
Pascal-Suisse, P.; Beaurain, P.; Mougniot, C.
A comparison of echographic techniques and NMR imaging has been done for the diagnosis of muscular trauma and tumor pathologies. In traumatic pathology, the echographic analysis allows to determine the complete assessment of recent muscular injuries. NMR imaging can be used in granuloma or fibrous callosity appreciation and for the analysis of deep injury (muscles and muscles-tendon junctions) and of muscular aponeurosis. Echography must be used together with color coding Doppler technique in the diagnosis of tumor pathology and for the study of slow fluxes. The recently available energy Doppler technique seems to be powerful in the study of vascularization of small expansive formations, but their extension to adjacent bone or tissue can only be appreciated using NMR imaging. (J.S.)
Aalund, Peter K; Larsen, Kristian; Hansen, Torben Bæk
OBJECTIVE: (s): To investigate which of the two muscle-impairment measures for the operated leg, normalized knee extension strength or leg press power, is more closely associated to performance-based and self-reported measures of function shortly following total knee arthroplasty (TKA). DESIGN...... and dynamic leg presses to determine their body-mass normalized knee extension strength and leg press power, respectively. The 10-m fast speed walking and 30-s chair stand tests were used to determine performance-based function, while the Western Ontario McMaster University Osteoarthritis Index (WOMAC......) and Oxford Knee scores were used to determine self-reported function. RESULTS: Normalized leg press power was more closely associated to both performance-based (r=.82, P...
Tod, David; Edwards, Christian; McGuigan, Mike; Lovell, Geoff
Researchers have tested the beliefs of sportspeople and sports medicine specialists that cognitive strategies influence strength performance. Few investigators have synthesised the literature. The specific objectives were to review evidence regarding (a) the cognitive strategy-strength performance relationship; (b) participant skill level as a moderator; and (c) cognitive, motivational, biomechanical/physiological, and emotional mediators. Studies were sourced via electronic databases, reference lists of retrieved articles, and manual searches of relevant journals. Studies had to be randomised or counterbalanced experiments with a control group or condition, repeated measures, and a quality control score above 0.5 (out of 1). Cognitive strategies included goal setting, imagery, self-talk, preparatory arousal, and free choice. Dependent variables included maximal strength, local muscular endurance, or muscular power. Globally, cognitive strategies were reliability associated with increased strength performance (results ranged from 61 to 65 %). Results were mixed when examining the effects of specific strategies on particular dependent variables, although no intervention had an overall negative influence. Indeterminate relationships emerged regarding hypothesised mediators (except cognitive variables) and participant skill level as a moderator. Although cognitive strategies influence strength performance, there are knowledge gaps regarding specific types of strength, especially muscular power. Cognitive variables, such as concentration, show promise as possible mediators.
Ryan, Eric D; Thompson, Brennan J; Sobolewski, Eric J
The present study examined the influence of workplace manual labor on measures of muscular fitness, with a secondary aim to investigate the relationship between muscular fitness and work performance in blue-collar (BC) workers. Leg extension isokinetic strength at slow and fast velocities, hamstring and hip-flexor flexibility, and low back muscular endurance were examined in young and older BC workers and white-collar (WC) controls, while work performance was examined in the BC cohort. There were no differences in muscular fitness variables between BC and WC groups; however, the older men had lower low back muscular endurance (-43.0%) and strength at slow (-9.4%) and fast (-12.7%) velocities. Work performance was associated with strength at fast velocities (r = 0.633) in the older BC workers. Leg strength may influence work performance, with higher velocities becoming more important in older workers.
Becker Muscular Dystrophy; Limb-Girdle Muscular Dystrophy, Type 2A (Calpain-3 Deficiency); Limb-Girdle Muscular Dystrophy, Type 2B (Miyoshi Myopathy, Dysferlin Deficiency); Limb-Girdle Muscular Dystrophy, Type 2I (FKRP-deficiency)
... protein. Often these boys are classified as having Becker muscular dystrophy. Genetic testing (looking at the body's genetic instructions) ... National Library of Medicine Web site Duchenne and Becker muscular dystrophy [ghr.nlm.nih.gov] From Genetics Home Reference ...
Maté-Muñoz, José Luis; Lougedo, Juan H; Barba, Manuel; García-Fernández, Pablo; Garnacho-Castaño, Manuel V; Domínguez, Raúl
CrossFit is a new strength and conditioning regimen involving short intense daily workouts called workouts of the day (WOD). This study assesses muscular fatigue levels induced by the three modalities of CrossFit WOD; gymnastics (G), metabolic conditioning (M) and weightlifting (W). 34 healthy subjects undertook three WOD (one per week): a G WOD consisting of completing the highest number of sets of 5 pull-ups, 10 push-ups and 15 air squats in 20 min; an M WOD, in which the maximum number of double skipping rope jumps was executed in 8 sets (20 s), resting (10 s) between sets; and finally, a W WOD in which the maximum number of power cleans was executed in 5 min, lifting a load equivalent to 40% of the individual's 1RM. Before and after each WOD, blood lactate concentrations were measured. Also, before, during, and after each WOD, muscular fatigue was assessed in a countermovement jump test (CMJ). Significant reductions were produced in the mechanical variables jump height, average power and maximum velocity in response to G; and in jump height, mean and peak power, maximum velocity and maximum force in response to W (P<0.01). However, in M, significant reductions in mechanical variables were observed between pre- and mid session (after sets 2, 4, 6 and 8), but not between pre- and post session. Muscular fatigue, reflected by reduced CMJ variables, was produced following the G and W sessions, while recovery of this fatigue was observed at the end of M, likely attributable to rest intervals allowing for the recovery of phosphocreatine stores. Our findings also suggest that the high intensity and volume of exercise in G and W WODs could lead to reduced muscular-tendon stiffness causing a loss of jump ability, related here to a longer isometric phase during the CMJ.
José Luis Maté-Muñoz
Full Text Available CrossFit is a new strength and conditioning regimen involving short intense daily workouts called workouts of the day (WOD. This study assesses muscular fatigue levels induced by the three modalities of CrossFit WOD; gymnastics (G, metabolic conditioning (M and weightlifting (W.34 healthy subjects undertook three WOD (one per week: a G WOD consisting of completing the highest number of sets of 5 pull-ups, 10 push-ups and 15 air squats in 20 min; an M WOD, in which the maximum number of double skipping rope jumps was executed in 8 sets (20 s, resting (10 s between sets; and finally, a W WOD in which the maximum number of power cleans was executed in 5 min, lifting a load equivalent to 40% of the individual's 1RM. Before and after each WOD, blood lactate concentrations were measured. Also, before, during, and after each WOD, muscular fatigue was assessed in a countermovement jump test (CMJ.Significant reductions were produced in the mechanical variables jump height, average power and maximum velocity in response to G; and in jump height, mean and peak power, maximum velocity and maximum force in response to W (P<0.01. However, in M, significant reductions in mechanical variables were observed between pre- and mid session (after sets 2, 4, 6 and 8, but not between pre- and post session.Muscular fatigue, reflected by reduced CMJ variables, was produced following the G and W sessions, while recovery of this fatigue was observed at the end of M, likely attributable to rest intervals allowing for the recovery of phosphocreatine stores. Our findings also suggest that the high intensity and volume of exercise in G and W WODs could lead to reduced muscular-tendon stiffness causing a loss of jump ability, related here to a longer isometric phase during the CMJ.
Bustamante, Mauricio; Liao, Wei
This study focuses on system analysis of a self-sustaining high-strength wastewater treatment concept combining solar technologies, anaerobic digestion, and aerobic treatment to reclaim water. A solar bio-hybrid power generation unit was adopted to power the wastewater treatment. Concentrated solar power (CSP) and photovoltaics (PV) were combined with biogas energy from anaerobic digestion. Biogas is also used to store the extra energy generated by the hybrid power unit and ensure stable and continuous wastewater treatment. It was determined from the energy balance analysis that the PV-bio hybrid power unit is the preferred energy unit to realize the self-sustaining high-strength wastewater treatment. With short-term solar energy storage, the PV-bio-hybrid power unit in Phoenix, AZ requires solar collection area (4032m 2 ) and biogas storage (35m 3 ), while the same unit in Lansing, MI needs bigger solar collection area and biogas storage (5821m 2 and 105m 3 , respectively) due to the cold climate. Copyright © 2017 Elsevier Ltd. All rights reserved.
Wroble, R R; Moxley, D R
In this study, football players (N = 57) in grades 9-11 from 3 high schools chose to participate in 1 of 2 groups. Group WC (N = 39) participated in off-season strength training only. Group SP (N = 18) participated in both a winter sport (either wrestling or basketball) and an identical strength training program. All participants were tested at the close of football season (Pre) and at the end of the winter sports season (Post), a period of 4 months. Body composition (weight [W] and body fat percentage [BF]), strength (calculated 1RM [1 repetition maximum] max for barbell bench press [BP] and squat [SQ]), power (vertical jump [VJ] and seated shot put [UP]), and agility (18.3-m agility run [AG]) were measured. Both groups WC and SP increased significantly in W and BF and improved significantly in BP and VJ (p training.
Henrik Petré, Pontus Löfving, Niklas Psilander
Full Text Available The effects of concurrent strength and endurance training have been well studied in untrained and moderately-trained individuals. However, studies examining these effects in individuals with a long history of resistance training (RT are lacking. Additionally, few studies have examined how strength and power are affected when different types of endurance training are added to an RT protocol. The purpose of the present study was to compare the effects of concurrent training incorporating either low-volume, high-intensity interval training (HIIT, 8-24 Tabata intervals at ~150% of VO2max or high-volume, medium-intensity continuous endurance training (CT, 40-80 min at 70% of VO2max, on the strength and power of highly-trained individuals. Sixteen highly-trained ice-hockey and rugby players were divided into two groups that underwent either CT (n = 8 or HIIT (n = 8 in parallel with RT (2-6 sets of heavy parallel squats, > 80% of 1RM during a 6-week period (3 sessions/wk. Parallel squat performance improved after both RT + CT and RT + HIIT (12 ± 8% and 14 ± 10% respectively, p < 0.01, with no difference between the groups. However, aerobic power (VO2max only improved after RT + HIIT (4 ± 3%, p < 0.01. We conclude that strength gains can be obtained after both RT + CT and RT + HIIT in athletes with a prior history of RT. This indicates that the volume and/or intensity of the endurance training does not influence the magnitude of strength improvements during short periods of concurrent training, at least for highly-trained individuals when the endurance training is performed after RT. However, since VO2max improved only after RT + HIIT and this is a time efficient protocol, we recommend this type of concurrent endurance training.
... is very similar to Duchenne, except kids with Becker MD may not have problems until much later, when they're teenagers or adults. It takes a long time for their muscles to become weak. How Does a Kid Get Muscular Dystrophy? MD is not contagious (say: con-TAY-juss), ...
The report summarises the studies carried out in Fortum Engineering (formerly IVO Power Engineering) between the years of 1992 and 1997 concerning ultimate strength of structures designed to mitigate and contain the consequences of various core melt accident scenarios. The report begins with the description of containment loading situations arising from core melt accidents. These situations are divided to fast and slow loads. Fast loads include ex-vessel steam explosions, steam spikes, hydrogen burns, direct containment heating and missiles. Slow loads are connected with pressure rise inside the containment in case when the containment heat removal system is not functioning. First part of report describes the analyses of reactor cavity based on axi-symmetric load assumptions. These studies are performed with various models like one degree of freedom idealisation, axi-symmetric modelling of geometry and full three-dimensional modelling of geometry. Second part of report describes the analyses of cavity based on non-axi-symmetric load assumptions. Here full 3D- geometry model is used combined with various physical models for the behaviour of reinforced concrete. Third part of report gives short account of the analysis of containment ultimate pressure capacity. The containment model in this case includes pre-stressing tendons and mild steel reinforcing bars. The load is assumed to axi-symmetric internal static pressure. The capacity of the reactor cavity against the ex-vessel steam explosion scenarios for VVER-91 plant concept is established for both axi-symmetric and non-axi-symmetric load models using ANACAP structural analysis code. The validation of the cavity response to ex-vessel steam explosion load using different commercially available codes gave mixed results for both axisymmetric and non-axi-symmetric load presentations.The ultimate static overpressure capacity of the VVER-91 reactor cavity structure was established to be of the order of 10 MPa. This result
Jacobson, Bert H; Conchola, Eric C; Smith, Doug B; Akehi, Kazuma; Glass, Rob G
Jacobson, BH, Conchola, EC, Smith, DB, Akehi, K, and Glass, RG. Relationship between selected strength and power assessments to peak and average velocity of the drive block in offensive line play. J Strength Cond Res 30(8): 2202-2205, 2016-Typical strength training for football includes the squat and power clean (PC) and routinely measured variables include 1 repetition maximum (1RM) squat and 1RM PC along with the vertical jump (VJ) for power. However, little research exists regarding the association between the strength exercises and velocity of an actual on-the-field performance. The purpose of this study was to investigate the relationship of peak velocity (PV) and average velocity (AV) of the offensive line drive block to 1RM squat, 1RM PC, the VJ, body mass (BM), and body composition. One repetition maximum assessments for the squat and PC were recorded along with VJ height, BM, and percent body fat. These data were correlated with PV and AV while performing the drive block. Peal velocity and AV were assessed using a Tendo Power and Speed Analyzer as the linemen fired, from a 3-point stance into a stationary blocking dummy. Pearson product analysis yielded significant (p ≤ 0.05) correlations between PV and AV and the VJ, the squat, and the PC. A significant inverse association was found for both PV and AV and body fat. These data help to confirm that the typical exercises recommended for American football linemen is positively associated with both PV and AV needed for the drive block effectiveness. It is recommended that these exercises remain the focus of a weight room protocol and that ancillary exercises be built around these exercises. Additionally, efforts to reduce body fat are recommended.
菊地, はるひ; 佐々木, 浩子
Sports Aerobics is the competitive sports including the complex aerobic step combination and difficulty elements. The competition time is 1 minute and 45±5 seconds. Sports Aerobics requires mainly anaerobic energy for competitive performance. But also it is very important to get the high capacity of aerobic power for performing the perfect execution. In this study, we tried to find out the characteristics for aerobic capacity and leg muscle strength in Sports Aerobics world champions (2 males...
Dohnert, Marcelo Baptista
Full Text Available Objetivo: Verificar o efeito agudo da crioterapia e da diatermia por ondas curtas na flexibilidade e força muscular de isquiotibiais de adultas jovens. Materiais e Métodos: Quarenta e cinco voluntárias foram randomizadas em grupo controle, grupo crioterapia e grupo diatermia por ondas curtas. Os sujeitos foram submetidos a uma única aplicação de crioterapia ou diatermia por ondas curtas. Foram avaliadas, pré e pós intervenção, a flexibilidade através do banco de Wells e do ângulo de extensão ativa do joelho, e a força muscular através da dinamometria. As variáveis foram analisadas por meio do teste t de Student e ANOVA. Resultados: Verificou-se um aumento significativo da flexibilidade dos isquiotibiais, tanto através do banco de Wells (24,50±6,88 cm para 26,87±8,02 cm (p=0,002, quanto na extensão ativa do joelho (162,60±7,76 graus para 165,53 ± 6,38 graus (p=0,015 no grupo diatermia. O grupo crioterapia mostrou melhora da flexibilidade no banco de Wells (23,27±6,33 cm para 25,53±6,13 cm (p=0,002. Não ocorreu aumento significativo da força muscular em nenhum dos grupos de intervenção. Não foi verificada diferença entre os grupos do estudo. Conclusão: Tanto a diatermia quanto a crioterapia melhoraram, de forma aguda, a flexibilidade dos isquiotibiais em mulheres adultas jovens e saudáveis. A termoterapia através da diatermia por ondas curtas mostrou-se mais efetiva nessa melhora. Ambos os recursos não alteraram a força muscular produzida pelos isquiotibiais
Balsalobre-Fernández, Carlos; Tejero-González, Carlos Mª; del Campo-Vecino, Juan; Alonso-Curiel, Dionisio
The aim of this study was to determine the effects of a power training cycle on maximum strength, maximum power, vertical jump height and acceleration in seven high-level 400-meter hurdlers subjected to a specific training program twice a week for 10 weeks. Each training session consisted of five sets of eight jump-squats with the load at which each athlete produced his maximum power. The repetition maximum in the half squat position (RM), maximum power in the jump-squat (W), a squat jump (SJ), countermovement jump (CSJ), and a 30-meter sprint from a standing position were measured before and after the training program using an accelerometer, an infra-red platform and photo-cells. The results indicated the following statistically significant improvements: a 7.9% increase in RM (Z=−2.03, p=0.021, δc=0.39), a 2.3% improvement in SJ (Z=−1.69, p=0.045, δc=0.29), a 1.43% decrease in the 30-meter sprint (Z=−1.70, p=0.044, δc=0.12), and, where maximum power was produced, a change in the RM percentage from 56 to 62% (Z=−1.75, p=0.039, δc=0.54). As such, it can be concluded that strength training with a maximum power load is an effective means of increasing strength and acceleration in high-level hurdlers. PMID:23717361
Petré, Henrik; Löfving, Pontus; Psilander, Niklas
The effects of concurrent strength and endurance training have been well studied in untrained and moderately-trained individuals. However, studies examining these effects in individuals with a long history of resistance training (RT) are lacking. Additionally, few studies have examined how strength and power are affected when different types of endurance training are added to an RT protocol. The purpose of the present study was to compare the effects of concurrent training incorporating either low-volume, high-intensity interval training (HIIT, 8-24 Tabata intervals at ~150% of VO2max) or high-volume, medium-intensity continuous endurance training (CT, 40-80 min at 70% of VO2max), on the strength and power of highly-trained individuals. Sixteen highly-trained ice-hockey and rugby players were divided into two groups that underwent either CT (n = 8) or HIIT (n = 8) in parallel with RT (2-6 sets of heavy parallel squats, > 80% of 1RM) during a 6-week period (3 sessions/wk). Parallel squat performance improved after both RT + CT and RT + HIIT (12 ± 8% and 14 ± 10% respectively, p HIIT (4 ± 3%, p HIIT in athletes with a prior history of RT. This indicates that the volume and/or intensity of the endurance training does not influence the magnitude of strength improvements during short periods of concurrent training, at least for highly-trained individuals when the endurance training is performed after RT. However, since VO2max improved only after RT + HIIT and this is a time efficient protocol, we recommend this type of concurrent endurance training. Key points Lower body maximal strength is improved after concurrent strength and endurance training in highly trained individuals. The magnitude of this strength improvement is not influenced by the type of endurance training, i.e. HIIT or CT. HIIT improves VO2max and is more time efficient than CT. HIIT is recommended to athletes when concurrently training for strength and endurance. PMID:29769816
Perraton, Luke G.; Bower, Kelly J.; Adair, Brooke; Pua, Yong-Hao; Williams, Gavin P.; McGaw, Rebekah
Introduction Hand-held dynamometry (HHD) has never previously been used to examine isometric muscle power. Rate of force development (RFD) is often used for muscle power assessment, however no consensus currently exists on the most appropriate method of calculation. The aim of this study was to examine the reliability of different algorithms for RFD calculation and to examine the intra-rater, inter-rater, and inter-device reliability of HHD as well as the concurrent validity of HHD for the assessment of isometric lower limb muscle strength and power. Methods 30 healthy young adults (age: 23±5yrs, male: 15) were assessed on two sessions. Isometric muscle strength and power were measured using peak force and RFD respectively using two HHDs (Lafayette Model-01165 and Hoggan microFET2) and a criterion-reference KinCom dynamometer. Statistical analysis of reliability and validity comprised intraclass correlation coefficients (ICC), Pearson correlations, concordance correlations, standard error of measurement, and minimal detectable change. Results Comparison of RFD methods revealed that a peak 200ms moving window algorithm provided optimal reliability results. Intra-rater, inter-rater, and inter-device reliability analysis of peak force and RFD revealed mostly good to excellent reliability (coefficients ≥ 0.70) for all muscle groups. Concurrent validity analysis showed moderate to excellent relationships between HHD and fixed dynamometry for the hip and knee (ICCs ≥ 0.70) for both peak force and RFD, with mostly poor to good results shown for the ankle muscles (ICCs = 0.31–0.79). Conclusions Hand-held dynamometry has good to excellent reliability and validity for most measures of isometric lower limb strength and power in a healthy population, particularly for proximal muscle groups. To aid implementation we have created freely available software to extract these variables from data stored on the Lafayette device. Future research should examine the reliability
Koh, Kyungtaek; Kim, Dogyeum; Park, Chunjin; Ryu, Gumsung; Park, Jungjun; Lee, Janghwa
Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates
Koh, Kyungtaek; Kim, Dogyeum; Park, Chunjin; Ryu, Gumsung; Park, Jungjun; Lee, Janghwa [Korea Institute Construction Technology, Goyang (Korea, Republic of)
Concrete undergoing early frost damage in cold weather will experience significant loss of not only strength, but also of permeability and durability. Accordingly, concrete codes like ACI-306R prescribe a minimum compressive strength and duration of curing to prevent frost damage at an early age and secure the quality of concrete. Such minimum compressive strength and duration of curing are mostly defined based on the strength development of concrete. However, concrete subjected to frost damage at early age may not show a consistent relationship between its strength and durability. Especially, since durability of concrete is of utmost importance in nuclear power plant structures, this relationship should be imperatively clarified. Therefore, this study verifies the feasibility of the minimum compressive strength specified in the codes like ACI-306R by evaluating the strength development and the durability preventing the frost damage of early age concrete for nuclear power plant. The results indicate that the value of 5 MPa specified by the concrete standards like ACI-306R as the minimum compressive strength to prevent the early frost damage is reasonable in terms of the strength development, but seems to be inappropriate in the viewpoint of the resistance to chloride ion penetration and freeze-thaw. Consequently, it is recommended to propose a minimum compressive strength preventing early frost damage in terms of not only the strength development, but also in terms of the durability to secure the quality of concrete for nuclear power plants in cold climates.
Thomaz, E.C.S.; Joia, L.A.
The concrete of the bored piles of Angra 2 was submitted to a deep control, so more than five thousand core samples were analyzed to verify the quality of the concrete. Based on these samples and using statistics regression theory some conclusions could be done. It was analyzed the dependence of the concrete strength upon the depth of the pile. Also based on these samples some probability distribution functions that could simulate the concrete strength were studied applying the Kolmogorov - Smirnov fitness test. Finally, a method for evaluating a confidence interval of one of the probability function (Weibull distribution) was developed adopting the Monte Carlo simulation technique. (Author) [pt
Løkken, Nicoline; Hedermann, Gitte; Thomsen, Carsten
We investigated whether a linear relationship between muscle strength and cross-sectional area (CSA) is preserved in calf muscles of patients with Becker muscular dystrophy (BMD, n = 14) and limb-girdle type 2I muscular dystrophy (LGMD2I, n = 11), before and after correcting for muscle fat...
Forsberg, C.W.; Norman, R.E.; Reich, W.J.; Hill, L.J.
The European nuclear power industry is being restructured from an industry drawn along national lines to a European-wide industry. This, in part, reflects growth of the European Economic Community, but it also reflects changes in the international nuclear power industry. The objectives of the participants, beyond better integration of the nuclear industry in Western Europe, are to (1) obtain European leadership of the worldwide commercial nuclear power industry, (2) improve medium- and long-term safety of Eastern Europe and the former Soviet Union (FSU) power reactors, and (3) reduce domestic concerns about nuclear power. The activities to achieve these goals include (1) formation of Nuclear Power International (a joint venture of the German and French nuclear power plant vendors for design and construction of nuclear power plants), (2) formation of a utility group to forge agreement throughout Europe on what the requirements are for the next generation of nuclear power plants, and (3) agreement by regulators in multiple European countries to harmonize regulations. This is to be achieved before the end of the decade. These changes would allow a single design of nuclear power plant to be built anywhere in Europe. The creation of European-wide rules (utility requirements, engineering standards, and national regulations) would create strong economic and political forces for other European countries (Eastern Europe and FSU) to meet these standards.
Forsberg, C.W.; Norman, R.E.; Reich, W.J.; Hill, L.J.
The European nuclear power industry is being restructured from an industry drawn along national lines to a European-wide industry. This, in part, reflects growth of the European Economic Community, but it also reflects changes in the international nuclear power industry. The objectives of the participants, beyond better integration of the nuclear industry in Western Europe, are to (1) obtain European leadership of the worldwide commercial nuclear power industry, (2) improve medium- and long-term safety of Eastern Europe and the former Soviet Union (FSU) power reactors, and (3) reduce domestic concerns about nuclear power. The activities to achieve these goals include (1) formation of Nuclear Power International (a joint venture of the German and French nuclear power plant vendors for design and construction of nuclear power plants), (2) formation of a utility group to forge agreement throughout Europe on what the requirements are for the next generation of nuclear power plants, and (3) agreement by regulators in multiple European countries to harmonize regulations. This is to be achieved before the end of the decade. These changes would allow a single design of nuclear power plant to be built anywhere in Europe. The creation of European-wide rules (utility requirements, engineering standards, and national regulations) would create strong economic and political forces for other European countries (Eastern Europe and FSU) to meet these standards
Verhoeven, A.A.C.; Adriaanse, M.A.; Evers, C.; de Ridder, D.T.D.
Objective. Although increasing evidence shows the importance of habits in explaining health behaviour, many studies still rely solely on predictors that emphasize the role of conscious intentions. The present study was designed to test the importance of habit strength in explaining unhealthy
The purpose of this research work is to track down the level of relation between strength and endurance in training exercises of handball athletes. The most successful ratio has been established during work with two groups of 10 players each, all of whom are university students. They were trained, respectively, according to the general training…
Matsumura, K.; Nakano, I.
By means of magnetic resonance imaging (MRI), the proton spin-lattice relaxation times (T1 values) of the skeletal muscles were measured in Duchenne muscular dystrophy (DMD) carriers and normal controls. The bound water fraction (BWF) was calculated from the T1 values obtained, according to the fast proton diffusion model. In the DMD carriers, T1 values of the gluteus maximus and quadriceps femoris muscles were significantly higher, and BWFs of these muscles were significantly lower than in normal control. Degenerative muscular changes accompanied by interstitial edema were presumed responsible for this abnormality. No correlation was observed between the muscle T1 and serum creatine kinase values. The present study showed that MRI could be a useful method for studying the dynamic state of water in both normal and pathological skeletal muscles. Its possible utility for DMD carrier detection was discussed briefly. (orig.)
Aertssen, Wendy F M; Ferguson, Gillian D; Smits-Engelsman, Bouwien C M
There is little and conflicting information about anaerobic performance and functional strength in children with Developmental Coordination Disorder (DCD). To investigate anaerobic capacity and functional strength in children with a clinical diagnosis of DCD (clin-DCD) and if differences were larger in older (age 7-10 years) compared to younger children (age 4-6 years). Furthermore to determine the percentage of children with clin-DCD that scored Strength Measurement. A clin-DCD group (36 boys, 11 girls, mean age: 7y 1mo, SD=2y 1mo) and a typically developing group (TD) (57 boys, 53 girls, mean age: 7y 5mo, SD=1y 10mo) were compared on Muscle Power Sprint Test (MPST) and Functional Strength Measurement (FSM). Children with clin-DCD performed poorer on the MPST and FSM, especially on the muscle endurance items of the FSM. The differences were larger in the older children compared to the younger on the cluster muscle endurance and the FSM total score. Over 50% of clin-DCD group scored tested on items requiring fast repetitive movements. Copyright © 2016 Elsevier Ltd. All rights reserved.
Owusu-Agyeman, Isaac; Shen, Junjie; Schäfer, Andrea Iris
Real water pH and ionic strength vary greatly, which influences the performance of membrane processes such as nanofiltration (NF) and reverse osmosis (RO). Systematic variation of pH (3-12) and ionic strength (2-10g/L as total dissolved solids (TDS)) was undertaken with a real Tanzanian water to investigate how water quality affects retention mechanisms of fluoride (F) and natural organic matter (NOM). An autonomous solar powered NF/RO system driven by a solar array simulator was supplied with constant power from a generator. An open NF (NF270) and a brackish water RO (BW30) membrane were used. A surface water with a very high F (59.7mg/L) and NOM (110mgC/L) was used. Retention of F by NF270 was 80% at pH4, and about 99% at pH >5, due to the smaller pore size and hence a more dominant size exclusion. In consequence, only little impact of ionic strength increase was observed for BW30. The concentration of NOM in permeates of both NF270 and BW30 were typically energy fluctuations, this research emphasises on feed water quality that affects system performance and may alter due to a number of environmental factors. Copyright © 2017 Elsevier B.V. All rights reserved.
G. V. Bezprozvannych
Full Text Available Introduction. Reliability of high voltage power cables in the process of long-term operation is largely due to the intensity of polymeric insulation aging. It is now established that the aging of polyethylene, which is the main material for the insulation of high voltage power cables, under the action of the electric field is determined primarily by the presence of structural heterogeneity arising both during cable production and during use. The cable is always there deviations from the ideal structure, which manifest in a deviation of diameters of conductors from nominal values; in the arrangement of the conductor and the insulation is not strictly coaxially and eccentrically; in elliptic (oval core and insulation; change in relative dielectric constant and thickness of insulation on cable length force the formation of low molecular weight products (including water in the flow at the manufacturing stage crosslinked polyethylene insulation and moisture during operation. Such defects are structural, technological and operational irregularities, which lead to a local change in the electric field. Purpose. Analysis of the influence of the eccentricity, elliptic and spherical inclusions in the electric field distribution in the power cable of a coaxial design with cross-linked polyethylene insulation, based on numerical simulation. Methodology. The bases of the numerical method of calculation of the electrical field strength are Fredholm integral equations of the first and second kind (method of secondary sources for an axially symmetric field. Analysis of the influence of irregularities, including water treeing, the shape of the sounding signal is made using the method of discrete resistive circuit inductance and capacitance of substitution with the initial conditions. Solving systems of linear algebraic equations nodal analysis performed by the sweep method. Results. The presence of the eccentricity and ellipticity in the construction of cable has
Full Text Available Abstract Background The identification of biologically interesting genes in a temporal expression profiling dataset is challenging and complicated by high levels of experimental noise. Most statistical methods used in the literature do not fully exploit the temporal ordering in the dataset and are not suited to the case where temporal profiles are measured for a number of different biological conditions. We present a statistical test that makes explicit use of the temporal order in the data by fitting polynomial functions to the temporal profile of each gene and for each biological condition. A Hotelling T2-statistic is derived to detect the genes for which the parameters of these polynomials are significantly different from each other. Results We validate the temporal Hotelling T2-test on muscular gene expression data from four mouse strains which were profiled at different ages: dystrophin-, beta-sarcoglycan and gamma-sarcoglycan deficient mice, and wild-type mice. The first three are animal models for different muscular dystrophies. Extensive biological validation shows that the method is capable of finding genes with temporal profiles significantly different across the four strains, as well as identifying potential biomarkers for each form of the disease. The added value of the temporal test compared to an identical test which does not make use of temporal ordering is demonstrated via a simulation study, and through confirmation of the expression profiles from selected genes by quantitative PCR experiments. The proposed method maximises the detection of the biologically interesting genes, whilst minimising false detections. Conclusion The temporal Hotelling T2-test is capable of finding relatively small and robust sets of genes that display different temporal profiles between the conditions of interest. The test is simple, it can be used on gene expression data generated from any experimental design and for any number of conditions, and it
International relations urgently needs theoretical development that takes into the account the power of non-state actors, in particular business. The present paper aims to prepare the ground for such theoretical development by analysing the political power of business along three dimensions: its
Petré, Henrik; Löfving, Pontus; Psilander, Niklas
The effects of concurrent strength and endurance training have been well studied in untrained and moderately-trained individuals. However, studies examining these effects in individuals with a long history of resistance training (RT) are lacking. Additionally, few studies have examined how strength and power are affected when different types of endurance training are added to an RT protocol. The purpose of the present study was to compare the effects of concurrent training incorporating either low-volume, high-intensity interval training (HIIT, 8-24 Tabata intervals at ~150% of VO 2max ) or high-volume, medium-intensity continuous endurance training (CT, 40-80 min at 70% of VO 2max ), on the strength and power of highly-trained individuals. Sixteen highly-trained ice-hockey and rugby players were divided into two groups that underwent either CT (n = 8) or HIIT (n = 8) in parallel with RT (2-6 sets of heavy parallel squats, > 80% of 1RM) during a 6-week period (3 sessions/wk). Parallel squat performance improved after both RT + CT and RT + HIIT (12 ± 8% and 14 ± 10% respectively, p HIIT (4 ± 3%, p HIIT in athletes with a prior history of RT. This indicates that the volume and/or intensity of the endurance training does not influence the magnitude of strength improvements during short periods of concurrent training, at least for highly-trained individuals when the endurance training is performed after RT. However, since VO 2max improved only after RT + HIIT and this is a time efficient protocol, we recommend this type of concurrent endurance training.
Secomb, Josh L; Lundgren, Lina E; Farley, Oliver R L; Tran, Tai T; Nimphius, Sophia; Sheppard, Jeremy M
The purpose of this study was to determine whether any relationships were present between lower-body muscle structure and strength and power qualities. Fifteen elite male surfing athletes performed a battery of lower-body strength and power tests, including countermovement jump (CMJ), squat jump (SJ), isometric midthigh pull (IMTP), and had their lower-body muscle structure assessed with ultrasonography. In addition, lower-body muscle-tendon complex (MTC) stiffness and dynamic strength deficit (DSD) ratio were calculated from the CMJ and IMTP. Significant relationships of large to very large strength were observed between the vastus lateralis (VL) thickness of the left (LVL) and right (RVL) leg and peak force (PF) (r = 0.54-0.77, p well as IMTP PF (r = 0.53-0.60, p = 0.02-0.04). Furthermore, large relationships were found between left lateral gastrocnemius (LG) pennation angle and SJ and IMTP PF (r = 0.53, p = 0.04, and r = 0.70, p < 0.01, respectively) and between LG and IMTP relative PF (r = 0.63, p = 0.01). Additionally, large relationships were identified between lower-body MTC stiffness and DSD ratio (r = 0.68, p < 0.01), right (LG) pennation angle (r = 0.51, p = 0.05), CMJ PF (r = 0.60, p = 0.02), and jump height (r = 0.53, p = 0.04). These results indicate that greater VL thickness and increased LG pennation angle are related to improved performance in the CMJ, SJ, and IMTP. Furthermore, these results suggest that lower-body MTC stiffness explains a large amount of variance in determining an athlete's ability to rapidly apply force during a dynamic movement.
Renata Gonçalves da Silva
Full Text Available The aim of this study was to investigate the effect of a whole body vibration training program on knee extensor isokinetic peak torque, average power, and functional tests in the physically active elderly. Forty-seven subjects, who participated in a training program for the elderly, were recruited. The subjects were divided into two groups: whole body vibration group (WBV (n=24, 70.7±5.8 years, 62.7±12.3 kg and 155.9±8.0 cm and control group (n=23. 70.0±5.7 years, 65.3±10.7 kg and 157.9±6.6 cm. The WBS group underwent whole body vibration exercise and their regular training program for 13 weeks, 2 times per week, whereas the control group performed the regular training program only. Whole body vibration training was not effective in increasing isokinetic peak torque, average power, or performance in the functional tests. On the other hand, the regular training program was effective in increasing elbow flexor strength endurance, distance covered in the 6-min walk test, and speed in the timed up and go test. The results suggest that vibration training is not effective in modifying functionality or muscle strength and power in the physically active elderly.
Pamukoff, Derek N; Haakonssen, Eric C; Zaccaria, Joseph A; Madigan, Michael L; Miller, Michael E; Marsh, Anthony P
Improving muscle strength and power may mitigate the effects of sarcopenia, but it is unknown if this improves an older adult's ability to recover from a large postural perturbation. Forward tripping is prevalent in older adults and lateral falls are important due to risk of hip fracture. We used a forward and a lateral single-step balance recovery task to examine the effects of strength training (ST) or power (PT) training on single-step balance recovery in older adults. Twenty older adults (70.8±4.4 years, eleven male) were randomly assigned to either a 6-week (three times/week) lower extremity ST or PT intervention. Maximum forward (FLean(max)) and lateral (LLean(max)) lean angle and strength and power in knee extension and leg press were assessed at baseline and follow-up. Fifteen participants completed the study (ST =7, PT =8). Least squares means (95% CI) for ΔFLean(max) (ST: +4.1° [0.7, 7.5]; PT: +0.6° [-2.5, 3.8]) and ΔLLean(max) (ST: +2.2° [0.4, 4.1]; PT: +2.6° [0.9, 4.4]) indicated no differences between groups following training. In exploratory post hoc analyses collapsed by group, ΔFLean(max) was +2.4° (0.1, 4.7) and ΔLLean(max) was +2.4° (1.2, 3.6). These improvements on the balance recovery tasks ranged from ~15%-30%. The results of this preliminary study suggest that resistance training may improve balance recovery performance, and that, in this small sample, PT did not lead to larger improvements in single-step balance recovery compared to ST.
Influência de variáveis do treinamento contra-resistência sobre a força muscular de idosos: uma revisão sistemática com ênfase nas relações dose-resposta Influencia de las variables de entrenamiento contra-resistencia sobre la fuerza muscular de ancianos: una revisión sistemática con énfasis en las relaciones dosis-respuesta Influence of counter-resistance training variables on elderly muscular strength: a systematic review with emphasis on dose/response relationships
Nádia Lima da Silva
tiene aún muy claro cuál es la mejor combinación de esas variables para una óptima relación dosis-respuesta en personas ancianas. El objetivo de este estudio ha sido analizar las investigaciones sobre entrenamiento de fuerza para ancianos, mediante una revisión sistemática, con el propósito de identificar tendencias comunes en términos de efectos del entrenamiento provocados por la manipulación de estas variables. Una vez definidos los criterios de inclusión, fueron seleccionados 22 estudios, agrupados por semejanza de tratamiento (nº de series, frecuencia semanal, intensidad, intervalos y orden de los ejercicios. Técnicas de estadística descriptiva auxiliaron en la determinación de posibles tendencias en las relaciones dosis-respuesta. Al identificarse, esas tendencias fueron analizadas cualitativamente. De todas las variables revisadas, solamente para la intensidad de sobrecarga fueron encontradas evidencias, lo que permite afirmar que cargas mayores serían más eficaces para inducir un aumento de fuerza a esa edad. En relación a las demás variables, los resultados disponibles en la literatura no dan respaldo para realizar inferencias seguras respecto al mejor delineamiento de programas de entrenamiento que alíen, al mismo tiempo, efectividad y seguridad. Por tanto, se recomienda que estudios posteriores sean realizados para comparar experimentalmente los efectos de la manipulación de esas variables sobre la fuerza muscular de ancianos.Muscular force is considered an important component of physical exercise programs. The results of this type of training depend on the combination of the number of repetitions, series, overload, sequence and intervals between series and exercises. However, it is still not very clear yet what the best combination of these variables for a good stimulus/response relationship in elderly people is. The objective of this study was to analyze the research on power-training for elderly people by means of systematic revision
Schkade, Janette K.; And Others
Twenty-five males with Duchenne muscular dystrophy were tested to assess their potential for occupational activity. Tests measured possible sensory deficits, strength, endurance, and fatigue in response to sustained fine motor activity. Results indicate that, within limitations, persons with this diagnosis can engage in activity leading to skill…
Gillen, Zachary M; Miramonti, Amelia A; McKay, Brianna D; Jenkins, Nathaniel D M; Leutzinger, Todd J; Cramer, Joel T
Gillen, ZM, Miramonti, AA, McKay, BD, Jenkins, NDM, Leutzinger, TJ, and Cramer, JT. Reliability and sensitivity of the power push-up test for upper-body strength and power in 6-15-year-old male athletes. J Strength Cond Res 32(1): 83-96, 2018-The power push-up (PPU) test is an explosive upper-body test performed on a force plate and is currently being used in high school football combines throughout the United States. The purpose of this study was to quantify the reliability of the PPU test based on age and starting position (knees vs. toes) in young athletes. Sixty-eight boys (mean ± SD; age = 10.8 ± 2.0 years) were tested twice over 5 days. Boys were separated by age as 6-9 years (n = 16), 10-11 years (n = 26), and 12-15 years (n = 26). The PPU test was performed on a force plate while rotating from the knees vs. the toes. Measurements were peak force (PF, N), peak rate of force development (pRFD, N·s), average power (AP, W), and peak power (PP, W). Intraclass correlation coefficients (ICC2,1), SEMs, coefficients of variation (CVs), and minimum detectable changes (MDCs) were calculated to quantify reliability and sensitivity. Peak force from the knees in 10-15-year-olds, PF from the toes in 12-15-year-olds, and pRFD from the knees and toes in 12-15-year-olds were comparably reliable (ICC ≥ 0.84). Neither power measurements (AP or PP) for any age group, nor any measurements (PF, pRFD, AP, or PP) for the 6-9-year-olds were comparably reliable (ICC ≤ 0.74). When considering the reliable variables, PF was greater in the 12-15-year-olds than in 10-11-year-olds (p ≤ 0.05). In addition, in 12-15-year-olds, PF and pRFD were greater from the knees than from the toes (p ≤ 0.05). For reasons largely attributable to growth and development, the PPU test may be a reliable (ICC ≥ 0.80) and sensitive (CV ≤ 19%) measure of upper-body strength (PF), whereas pRFD was also reliable (ICC ≥ 0.80), but less sensitive (CV = 30-38%) in 10-15-year-old male athletes.
... Marie-Tooth Disease (CMT) Congenital Muscular Dystrophy (CMD) Duchenne Muscular Dystrophy (DMD) Emery-Dreifuss Muscular Dystrophy Endocrine Myopathies Metabolic Diseases of Muscle Mitochondrial Myopathies (MM) Myotonic Dystrophy (DM) Spinal-Bulbar ...
Bilsborough, Johann C; Greenway, Kate G; Opar, David A; Livingstone, Steuart G; Cordy, Justin T; Bird, Stephen R; Coutts, Aaron J
The aim of this study was to compare the anthropometry, upper-body strength, and lower-body power characteristics in elite junior, sub-elite senior, and elite senior Australian Football (AF) players. Nineteen experienced elite senior (≥4 years Australian Football League [AFL] experience), 27 inexperienced elite senior (free soft tissue mass [FFSTM], fat mass, and bone mineral content) with dual-energy x-ray absorptiometry, upper-body strength (bench press and bench pull), and lower-body power (countermovement jump [CMJ] and squat jump with 20 kg). A 1-way analysis of variance assessed differences between the playing levels in these measures, whereas relationships between anthropometry and performance were assessed with Pearson's correlation. The elite senior and sub-elite senior players were older and heavier than the elite junior players (p ≤ 0.05). Both elite playing groups had greater total FFSTM than both the sub-elite and junior elite players; however, there were only appendicular FFSTM differences between the junior elite and elite senior players (p squat performance measures (r = 0.33-0.55). Australian Football players' FFSTM are different between playing levels, which are likely because of training and partly explain the observed differences in performance between playing levels highlighting the importance of optimizing FFSTM in young players.
Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István
The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 - 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer.
Váczi, Márk; Tollár, József; Meszler, Balázs; Juhász, Ivett; Karsai, István
The aim of the present study was to investigate the effects of a short-term in-season plyometric training program on power, agility and knee extensor strength. Male soccer players from a third league team were assigned into an experimental and a control group. The experimental group, beside its regular soccer training sessions, performed a periodized plyometric training program for six weeks. The program included two training sessions per week, and maximal intensity unilateral and bilateral plyometric exercises (total of 40 – 100 foot contacts/session) were executed. Controls participated only in the same soccer training routine, and did not perform plyometrics. Depth vertical jump height, agility (Illinois Agility Test, T Agility Test) and maximal voluntary isometric torque in knee extensors using Multicont II dynamometer were evaluated before and after the experiment. In the experimental group small but significant improvements were found in both agility tests, while depth jump height and isometric torque increments were greater. The control group did not improve in any of the measures. Results of the study indicate that plyometric training consisting of high impact unilateral and bilateral exercises induced remarkable improvements in lower extremity power and maximal knee extensor strength, and smaller improvements in soccer-specific agility. Therefore, it is concluded that short-term plyometric training should be incorporated in the in-season preparation of lower level players to improve specific performance in soccer. PMID:23717351
Full Text Available In area of flat defect, predefined a gradient tireless - corrosive tensions, a double electric layer, conditioned the spatial redistribution of electronic closeness, is formed. It shows up a local rejection mikro-thermo-power at use of heating edge of tungsten thermocouple. Test approbation of method is conducted on the deformed chromel.
Full Text Available The support structure being the object of the analysis presented in the article is Tripod. According to the adopted assumptions, it is a foundation gravitationally set in the water region of 60 m in depth, not fixed to the seabed, which can be used for installing a 7MW wind turbine. Due to the lack of substantial information on designing and strength calculations of such types of structures in the world literature, authors have made an attempt to solve this problem within the framework of the abovementioned project. In the performed calculations all basic loads acting on the structure were taken into account, including: the self mass of the structure, the masses of the ballast, the tower and the turbine, as well as hydrostatic forces, and aero- and hydrodynamic forces acting on the entire object in extreme operating conditions.
Vaisman, Alex; Guiloff, Rodrigo; Rojas, Juan; Delgado, Iris; Figueroa, David; Calvo, Rafael
Achieving a symmetrical power performance (difference power between the dominant and nondominant legs in healthy young adults, (2) evaluate the effect of a single-leg-dominant sport activity performed at the professional level, and (3) propose a parameter of normality for maximal power difference in the lower limbs of this young adult population. Controlled laboratory study. A total of 78 healthy, male, young adults were divided into 2 groups according to sport activity level. Group 1 consisted of 51 nonathletes (mean ± SD age, 20.8 ± 1.5 years; weight, 71.9 ± 10.5 kg) who participated in less than 8 hours a week of recreational physical activity with nonspecific training; group 2 consisted of 27 single-leg-dominant professional soccer players (age, 18.4 ± 0.6 years; weight, 70.1 ± 7.5 kg) who specifically trained and competed at their particular activity 8 hours or more a week. For assessment of maximal leg power, both groups completed the single-leg squat jump test. Dominance was determined when participants completed 2 of 3 specific tests with the same extremity. Statistical analysis included the Student t test. No statistical difference was found for maximal power between dominant and nondominant legs for nonathletes ( t = -1.01, P = .316) or single-leg-dominant professional soccer players ( t = -1.10, P = .281). A majority (95%) of participants studied showed a power difference of less than 15% between their lower extremities. Among young healthy adults, symmetrical power performance is expected between lower extremities independent of the existence of dominance and difference in sport activity level. A less than 15% difference in power seems to be a proper parameter to define symmetrical power performance assessed by vertical single-leg jump tests.
Influência de um programa de atividade física de longa duração sobre a força muscular manual e a flexibilidade corporal de mulheres idosas Influence of a long-term physical activity program on hand muscle strength and body flexibility among elderly women
Full Text Available Objetivo: O presente trabalho examinou a influência de um programa de exercícios físicos prolongados (dois anos sobre a força muscular e a flexibilidade corporal de mulheres idosas (60-80 anos, não institucionalizadas, da Província de Salamanca (Espanha. Método: Participaram 32 sujeitos, escolhidos dentre os participantes do Programa de Revitalização Geriátrica desenvolvido pela Universidade de Salamanca. Os critérios para escolha dos sujeitos foram: serem do sexo feminino, terem entre 60 e 80 anos e terem participado de pelo menos 74% do programa de atividades físicas. Foram realizadas 174 sessões de atividade física, durante 58 semanas, com freqüência de três vezes por semana e duração de 50 a 55 minutos cada uma. No período do experimento foram realizadas quatro medidas da força muscular manual, por meio de manômetro de pressão, e da flexibilidade corporal, por meio do teste sit and reach. Os dados foram analisados por meio de ANOVA com medidas repetidas. Resultados: Tanto em relação à força muscular, quanto à flexibilidade os dados apontam para a ausência de diferenças significativas (p= 0,005. Conclusões: O programa contribuiu para a manutenção da força de preensão manual no período de dois anos e, em relação à flexibilidade corporal, os dados indicam a necessidade de reprogramação dos exercícios destinados ao desenvolvimento de tal capacidade.Objective: The present study evaluated the influence of a two-year physical activity program on muscle strength and body flexibility among non-institutionalized elderly women (60-80 years old, from Salamanca Province in Spain. Method: Thirty-two individuals were chosen to take part in the Geriatric Revitalization Program at Salamanca University. The selection criteria were that they should be female, between 60 and 80 years old, with an attendance rate of at least 74% in the physical activity program. There were 174 physical activity sessions, over a 58-week
Efeitos de diferentes esforços de luta de judô na atividade enzimática, atividade elétrica muscular e parâmetros biomecânicos de atletas de elite Los efectos de diferentes esfuerzos de lucha del judo en la actividad enzimática, actividad eléctrica muscular y biomecánica de los parámetros de atletas de élite Effects of different strengths in the judo fights, muscular electrical activity and biomechanical parameters in elite athletes
Silvia Regina Ribeiro
tensión de las luchas del judo.The sportive training causes neuromuscular adaptations and metabolic alterations aiming the competition performance. In judo competitions, the number of fights to what athletes are submitted, as well as their respective endurance and intervals are randomized, and these factors may influence the aimed training performance. This study investigated the hypothesis that different fight endurances, 90s, 180s, and 300s could influence the enzymatic and muscular electrical activity, as well as the torque peak production. Before and after each fighting, a blood sampling was collected from each athlete. After and before each fight, they performed five dynamic contractions (90º/s using an isokinetic Dynamometer (Biodex System 3. Simultaneously, it was recorded the electromyographic signal of the agonist, antagonist and synergistic muscles of the movement assessed. It was observed no alterations in the torque. The AST and ALT enzymes presented an increasing activity in the 90 sec. (p = 0.0033/p = 0.00059, 180 sec. (p = 0.0044/p = 0.0033, and in the 300 sec. (p = 0.0044/p = 0.0033 fights. It was verified an increase (p = 0.0180 in the CK activity after the 300 sec. fight. LDH decreased after the 90 sec. fight (p = 0.0392. Upon the intermuscular analysis, it was observed an increase in the electromyographic signal of the agonist muscle after the 90 sec. fight (p = 0.005, an increase of the antagonist muscle in the 180 sec. fight (p = 0.0129, and a decrease (p = 0.0137 in the activity of the agonist muscle in the 300 sec. fight. It was observed that the strength in the 300 sec. fight might reduced the injuries in the muscular tissue characterized by a raise in the plasmatic CK, although the injury was not sufficient to detect the fatigue through the isokinetic dynamometry. It can be concluded that the proposed protocol was sufficient to the enzymatic and electromyographic alteration, suggesting metabolic and neural adaptations from stress caused by the
Frost, David M; Bronson, Stefanie; Cronin, John B; Newton, Robert U
Because free weight (FW) and pneumatic (PN) resistance are characterized by different inertial properties, training with either resistance could afford unique strength, velocity, and power adaptations. Eighteen resistance-trained men completed baseline tests to determine their FW and PN bench press 1 repetition maximum (1RM). During the FW session, 4 explosive repetitions were performed at loads of 15, 30, 45, 60, 75, and 90% 1RM to assess force, velocity, and power. Participants were then assigned to a FW or PN training group, which involved three 90-minute sessions per week for 8 weeks. Both intervention groups completed identical periodized programs with the exception of the resistance used to perform all bench press movements. Free weight participants significantly increased their FW and PN 1RM (10.4 and 9.4%), and maximum (any load) force (9.8%), velocity (11.6%), and power (22.5%). Pneumatic-trained participants also exhibited increases in FW and PN 1RM (11.6 and 17.5%), and maximum force (8.4%), velocity (13.6%), and power (33.4%). Both interventions improved peak barbell velocity at loads of 15 and 30% 1RM; however, only the PN-trained individuals displayed improvements in peak force and power at these same loads. Training with PN resistance may offer advantages if attempting to improve power at lighter relative loads by affording an opportunity to consistently achieve higher accelerations and velocities (F = ma), in comparison with FW. Exploiting the inertial properties of the resistance, whether mass, elastic or PN, could afford an opportunity to develop mixed-method training strategies and/or elicit unique neuromuscular adaptations to suit the specific needs of athletes from sports characterized by varying demands.
Bartolomei, Sandro; Fukuda, David H; Hoffman, Jay R; Stout, Jeffrey R; Merni, Franco
The purpose of this study was to compare the power expressed during the bench press exercise in resistance-trained men following different pre-activation conditions. Twenty-two trained men (age 24.1 ± 1.7 years, height 178.6 ± 6.1 cm, body mass 81.1 ± 10.6 kg) completed a maximal effort bench press (1-RM) test (100.0 kg ± 8.1 kg). In a subsequent assessment, each participant performed concentric bench press movements with loads of 20%, 30%, 40% and 50% of their 1-RM preceded by either a concentric contraction (CC), a low isometric preload (LIP; 70% 1-RM) or a high isometric preload (HIP; 100% 1-RM) conditions. All movements were performed in a Smith machine with a settable quick-release device. Participants performed all three conditions in randomized fashion. Results indicated that power outputs during the bench press exercise following HIP were significantly (p < 0.05) greater than CC at 20% 1-RM (+9%), 30% 1-RM (+16%) and 40% 1-RM (+14%), and LIP at 20% 1-RM (+4%), 30% 1-RM (+20%) and 40% 1-RM (+15%). No differences were found between conditions at 50% 1-RM. Area under the force-power curve with HIP was greater (p < 0.05) than with CC and LIP. In conclusion, results of this study indicate that the use of a HIP (100% 1-RM) in trained participants results in significantly greater power output during the concentric phase of a multi-joint exercise when compared to standard concentric movement.
Blas, J. de
Following the accident at the Fukushima-Daiichi power plants, the electrical sector of nuclear generation recognised the need to reinforce the capacities that the nuclear power plants already had and which they were developing in order to satisfy the requisites of the stress tests, with the additional support of equipment and human resources common to all of them. Thus the idea arose to create a Spanish emergency Support centre. Its scope included an intervention unit, pumping equipment and electrical generation, a centralised warehouse and transfer logistics. UNESA-UME Collaboration Protocol With the collaboration of the CSN as a mediator, the UME reached an agreement with the nuclear electrical sector (UNESA) in order to be able to increase knowledge about the Spanish nuclear power plants and establish a means of collaboration to be able to act with their own human and equipment resources at a site that might suffer an accident such as the one at the Japanese plants of Fukushima-Daiichi. (Author)
van Vulpen, Liesbeth F; de Groot, Sonja; Rameckers, Eugene; Becher, Jules G; Dallmeijer, Annet J
Background. Strength training programs for children with cerebral palsy (CP) showed inconclusive evidence for improving walking, despite improvements in strength. Recent studies have suggested that strength training with high movement velocity is more effective for improving walking than traditional
Full Text Available The paper presents a method for determination of thermo-flow parameters for steam boilers. This method allows to perform the calculations of the boiler furnace chamber and heat flow rates absorbed by superheater stages. These parameters are important for monitoring the performance of the power unit. Knowledge of these parameters allows determining the degree of the furnace chamber slagging. The calculation can be performed in online mode and use to monitoring of steam boiler. The presented method allows to the operation of steam boiler with high efficiency.
Laugesen, Søren; Ohlrich, Mogens
Simple, yet reliable methods for the approximate determination of the vibratory power supplied by the internal excitation forces of a given vibrational source are of great interest. One such method that relies on the application of a number of “equivalent forces” and measurements of the mean...... squared velocity on either the source or the receiving structure is studied in this paper by means of computer simulations. The study considers a simple system of two flexural beams coupled via a pair of springs. The investigation shows that a relatively small number of equivalent forces suffice...
Ovchinnikov, A.V.; Rivkin, E.Yu.; Vasilchenko, G.S.; Zvezdin, Yu.I.
Several kinds of test specimens were produced with three types of defects of defined sizes and positions in the particular localities of weld joints. Such specimens have been used for defect parameter characterization by ultrasonic testing. The principles for schematization of such defects and the formulae for the stress intensity factor calculations for elliptical and semielliptical cracks have been worked out. Methods for defining the sizes of defect which are acceptable have been designed for use for use on operational nuclear power plant equipment and take account of the mutual effects of the force, thermal and residual stresses. The method can be used in the brittle, transitional and tough material state. (author)
PURPOSE OF REVIEW: The aim of the study was to describe the clinical spectrum of limb girdle muscular dystrophies (LGMDs), the pitfalls of the current classification system for LGMDs, and emerging therapies for these conditions. RECENT FINDINGS: Close to half of all LGMD subtypes have been...... or are registered in other classification systems for muscle disease. On the contrary, diseases that fulfill classical criteria for LGMD have found no place in the LGMD classification system. These shortcomings call for revision/creation of a new classification system for LGMD. The rapidly expanding gene sequencing...... capabilities have helped to speed up new LGMD discoveries, and unveiled pheno-/genotype relations. Parallel to this progress in identifying new LGMD subtypes, emerging therapies for LGMDs are under way, but no disease-specific treatment is yet available for nonexperimental use. SUMMARY: The field of LGMD...
Full Text Available Based on a geographical-administrative definition of the region, the theoretical assumptions of contemporary French structuralist geopolitics, cross-sectional data for 1990, 1995, 2000, 2005 and 2010 from the Updated Arctic Regional Attributes Dataset, and the technical capabilities of MS Office Excel 2010, this research (a reveals and contrasts the Arctic states’ capability constraints deriving from their longitudinal material and virtual power potential (physical potential, socio-economic potential, military potential, and symbolic potential; and (b analyses the role of this constraint in the process of preference formation in case of one specific Arctic actor, Russia, in the Arctic territorial dispute. This study confirms that Russia’s capability constraint is the lowest in the region and that the latter does not form a stable trend throughout the period studied. It also suggests the preference formation framework for Russia in the Arctic dispute based on the evolution of its polar capability constraint.
Ahmad, J.; Purbolaksono, J.; Beng, L.C.; Ahmad, A. [University of Tenaga Nas, Kajang (Malaysia). Dept. of Mechanical Engineering
This article presents failure investigation on a high-strength alloy SA213-T91 superheater tube. This failure is the first occurrence involving the material in Kapar Power Station Malaysia. The investigation includes visual inspections, hardness measurements, and microscopic examinations. The failed super-heater tube shows a wide open rupture with thin and blunt edges. Hardness readings on all the as-received tubes are used for estimating the operating metal temperature of the super-heater tubes. Microstructures of the failed tube show numerous creep cavities consisting of individual pores and chain of pores which form micro-and macro-cracks. The findings confirmed that the super-heater tube is failed by short-term overheating. Higher temperatures of the flue gas due to the inconsistent feeding of pulverized fuels into the burner is identified to cause overheating of the failed tube.
Korman, S H; Bar-Oz, B; Granot, E; Meyer, S
Smooth muscle degeneration may occur in Duchenne muscular dystrophy. We measured fasting orocaecal transit time in patients with advanced Duchenne muscular dystrophy and other muscular dystrophies and in healthy controls. No significant differences were found. In contrast to reports of gastric hypomotility in Duchenne muscular dystrophy, we found no evidence of impaired small intestinal motility.
Feriche, Bel?n; Garc?a-Ramos, Amador; Morales-Artacho, Antonio J.; Padial, Paulino
The possible muscular strength, hypertrophy, and muscle power benefits of resistance training under environmental conditions of hypoxia are currently being investigated. Nowadays, resistance training in hypoxia constitutes a promising new training strategy for strength and muscle gains. The main mechanisms responsible for these effects seem to be related to increased metabolite accumulation due to hypoxia. However, no data are reported in the literature to describe and compare the efficacy of...
Hoekstra, T.; Boreham, Colin A; Murray, Liam J; Twisk, Jos W R
BACKGROUND: It is not clear what the relative contribution is of specific components of physical fitness (aerobic and muscular) to cardiovascular disease (CVD) risk. We investigated associations between aerobic fitness (endurance) and muscular fitness (power) and CVD risk factors. METHODS: Data were
D’Angelo, Maria Grazia; Lorusso, Maria Luisa; Civati, Federica; Comi, Giacomo Pietro; Magri, Francesca; Del Bo, Roberto; Guglieri, Michela; Molteni, Massimo; Turconi, Anna Carla; Bresolin, Nereo
The presence of nonprogressive cognitive impairment is recognized as a common feature in a substantial proportion of patients with Duchenne muscular dystrophy. To investigate the possible role of mutations along the dystrophin gene affecting different brain dystrophin isoforms and specific cognitive profiles, 42 school-age children affected with Duchenne muscular dystrophy, subdivided according to sites of mutations along the dystrophin gene, underwent a battery of tests tapping a wide range of intellectual, linguistic, and neuropsychologic functions. Full-scale intelligence quotient was approximately 1 S.D. below the population average in the whole group of dystrophic children. Patients with Duchenne muscular dystrophy and mutations located in the distal portion of the dystrophin gene (involving the 140-kDa brain protein isoform, called Dp140) were generally more severely affected and expressed different patterns of strengths and impairments, compared with patients with Duchenne muscular dystrophy and mutations located in the proximal portion of the dystrophin gene (not involving Dp140). Patients with Duchenne muscular dystrophy and distal mutations demonstrated specific impairments in visuospatial functions and visual memory (which seemed intact in proximally mutated patients) and greater impairment in syntactic processing. PMID:22000308
Mascarin, Naryana Cristina; de Lira, Claudio Andre Barbosa; Vancini, Rodrigo Luiz; de Castro Pochini, Alberto; da Silva, Antonio Carlos; Dos Santos Andrade, Marilia
Imbalance in shoulder-rotator muscles has been considered a risk factor for injuries in handball. Strength training programs (STPs) may play an important preventive role. To verify the effects of an STP using elastic bands on shoulder muscles and ball-throwing speed. Randomized and prospective controlled trial. Exercise physiology laboratory. Thirty-nine female handball players were randomly assigned to an experimental (EG, n = 21, 15.3 ± 1.1 y) or a control (CG, n = 18, 15.0 ± 0.8 y) group. The EG performed the STP with elastic-band progressive exercises for 6 wk before regular handball training, and the CG underwent only their regular training. Before and after the STP, both groups underwent a ball-throwing-speed test and isokinetic test to assess shoulder internal- (IR) and external-rotator muscle performance. Average power values for IR muscles presented a significant group-vs-time interaction effect (F = 3.9, P = .05); EG presented significantly higher values after the STP (P = .03). Ball speed presented higher values in EG after the STP in standing (P = .04) and jumping (P = .03) throws. IR peak-torque values and balance in shoulder-rotator muscles presented no group-vs-time interaction effect. STP using elastic bands performed for 6 wk was effective to improve muscle power and ball speed for young female handball players.
Full Text Available Background: β-Hydroxy-β-methylbutyrate-free acid (HMB-FA has been ingested prior to exercise to reduce muscle damage, however the effects of HMB-FA supplementation on hormonal, strength and power adaptation are unclear. Methods: Sixteen healthy men were matched and randomized into two groups and performed six-week resistance training while supplementing with either HMB-FA or placebo (3 g per day. The subjects were evaluated for 1 repetition maximum (1RM bench press and leg press and vertical jump (VJ prior to and after training intervention. In addition, blood samples were obtained before and after resistance training to evaluate resting growth hormone (GH, insulin like growth factor 1 (IGF-1, testosterone (TEST, cortisol (CORT, and adrenocorticotropic hormone (ACTH responses. The HMB-FA supplementation group showed greater gains compared with the placebo group in peak power (effect size ES = 0.26 vs. 0.01 and 1RM leg press (ES = 1.52 vs. 0.96. In addition, the HMB-FA supplementation group indicated greater decrements in ACTH and CORT responses to training in comparison to the placebo group (p < 0.05. Likewise, in GH (ES = 1.41 vs. 0.12 and IGF-1 (ES = 0.83 vs. 0.41, the HMB-FA indicated greater training effects when compared with the placebo group. Conclusions: These findings provide further support for the potential anabolic benefits associated with HMB-FA supplementation.
... of muscular dystrophy appeared in 1830, when Sir Charles Bell wrote an essay about an illness that ... linked disorder to their sons but their daughters will be carriers of that disorder. Carrier females occasionally ...
Wachter, Nikolaus Johannes; Mentzel, Martin; Krischak, Gert D; Gülke, Joachim
In the assessment of hand and upper limb function, grip strength is of the major importance. The measurement by dynamometers has been established. In this study, the effect of a simulated ulnar nerve lesion on different grip force measurements was evaluated. In 25 healthy volunteers, grip force measurement was done by the JAMAR dynamometer (Fabrication Enterprises Inc, Irvington, NY) for power grip and by a pinch strength dynamometer for tip pinch strength, tripod grip, and key pinch strength. A within-subject research design was used in this prospective study. Each subject served as the control by preinjection measurements of grip and pinch strength. Subsequent measurements after ulnar nerve block were used to examine within-subject change. In power grip, there was a significant reduction of maximum grip force of 26.9% with ulnar nerve block compared with grip force without block (P force could be confirmed. However, the assessment of other dimensions of hand strength as tip pinch, tripod pinch and key pinch had more relevance in demonstrating hand strength changes resulting from an distal ulnar nerve lesion. The measurement of tip pinch, tripod grip and key pinch can improve the follow-up in hand rehabilitation. II. Copyright © 2017 Hanley & Belfus. Published by Elsevier Inc. All rights reserved.
Full Text Available A suplementação de creatina vem sendo utilizada amplamente na tentativa de aumentar força e massa magra em sujeitos saudáveis e atletas. Além disso, diversos estudos têm sido conduzidos no intuito de desvendar os mecanismos responsáveis pelas eventuais adaptações a esse suplemento. Diante disso, essa revisão teve como objetivos: 1 discutir os principais estudos que investigaram os efeitos da suplementação de creatina na força e hipertrofia; e 2 reunir as evidências acerca dos possíveis mecanismos responsáveis pelo aumento de força e massa magra como consequência desse suplemento, enfatizando os mais recentes achados e as perspectivas sobre o tema. De fato, existem fortes evidências demonstrando que a suplementação de creatina é capaz de promover aumentos de força e hipertrofia. Os efeitos desse suplemento sobre a retenção hídrica, o balanço proteico, a expressão de genes/proteínas associados à hipertrofia e ativação de células satélites, podem explicar as adaptações musculoesqueléticas observadas. Diante desses achados, os potenciais efeitos terapêuticos desse suplemento emergem como um futuro e promissor campo de estudo.Creatine supplementation has been widely used to increase both muscle strength and lean mass in healthy individuals and athletes. Furthermore, several studies have investigated the mechanisms responsible for such adaptations. Thus, this review aimed at 1 examining the major studies investigating the effects of creatine supplementation on strength and hypertrophy, and 2 exploring the mechanisms underlying these responses, stressing the most recent findings and perspectives regarding creatine supplementation. There is strong evidence demonstrating that creatine supplementation is able to enhance strength and hypertrophy. The effects of creatine on water retention, protein balance, genes/proteins related to hypertrophy, and satellite cells activation may explain the creatine-mediated muscle
Potteiger, Jeffrey A; Smith, Dean L; Maier, Mark L; Foster, Timothy S
The purpose of this study was to examine relationships between laboratory tests and on-ice skating performance in division I men's hockey athletes. Twenty-one men (age 20.7 +/- 1.6 years) were assessed for body composition, isokinetic force production in the quadriceps and hamstring muscles, and anaerobic muscle power via the Wingate 30-second cycle ergometer test. Air displacement plethysmography was used to determine % body fat (%FAT), fat-free mass (FFM), and fat mass. Peak torque and total work during 10 maximal effort repetitions at 120 degrees .s were measured during concentric muscle actions using an isokinetic dynamometer. Muscle power was measured using a Monark cycle ergometer with resistance set at 7.5% of body mass. On-ice skating performance was measured during 6 timed 89-m sprints with subjects wearing full hockey equipment. First length skate (FLS) was 54 m, and total length skate (TLS) was 89 m with fastest and average skating times used in the analysis. Correlation coefficients were used to determine relationships between laboratory testing and on-ice performance. Subjects had a body mass of 88.8 +/- 7.8 kg and %FAT of 11.9 +/- 4.6. First length skate-Average and TLS-Average skating times were moderately correlated to %FAT ([r = 0.53; p = 0.013] and [r = 0.57; p = 0.007]) such that a greater %FAT was related to slower skating speeds. First length skate-Fastest was correlated to Wingate percent fatigue index (r = -0.48; p = 0.027) and FLS-Average was correlated to Wingate peak power per kilogram body mass (r = -0.43; p = 0.05). Laboratory testing of select variables can predict skating performance in ice hockey athletes. This information can be used to develop targeted and effective strength and conditioning programs that will improve on-ice skating speed.
Koh, Kyung Teak; Park, Chun Jin; Ryu, Gum Sung; Kim, Do Gyeum; Lee, Jang Hwa [Korea Institute of Construction Technology, Goyang (Korea, Republic of)
As a part of a Department of Energy-Nuclear According to the specifications for the construction execution for a nuclear power plant (NPP), the cold weather concrete should be facilitated that comply with the regulations of ACI-306R. Here, in terms of the standards applied to the cold weather concrete, such concrete should be applied in the case where the daily average temperature is 5 .deg. C or less. So, according to the analysis on the average temperature in winter over the last one year at each NPP construction area, it was found that such had lowered by about 0.5 - 2 .deg. C as compared to the temperature during the normal years (the last ten years) and the number of days applied to the cold weather concrete according to the ACI regulations was shown as 83, so as around 1/4 of year falls into the cold weather conditions and furthermore the recent weather is getting severe, it is necessary to perform the appropriate insulation curing for the cold weather concrete. On the other hand, according to the regulations with regards to the curing conditions for cold weather concrete, the insulation curing of such should be appropriately performed under an environment of 5 .deg. C or greater until the strength of 3.5 MPa (500 Psi) develops. Likewise, according to the regulations regarding the cold weather concrete in the domestic concrete specifications, the insulation curing should be performed until a strength development of 5 MPa (715 Psi) considering the safety factor indicated to the ACI regulation under the temperature of 5 .deg. C or greater. According to the above-mentioned regulations, the NPP structure is required to develop a minimum strength of 5 MPa or greater, and to maintain such important qualities, including strength development, early anti-freezing and duality under cold weather conditions. However, even though the early strength of 5 MPa or greater is secured under the recent abnormal weather conditions and cold weather conditions, if the structure is
Kroll, Walter; And Others
There is a degree of uniqueness in fatigue patterns, particularly between different levels of absolute maximum strength. Caution should be used when analyzing fatigue curves among subjects with unspecified strength levels. (CJ)
Testes de força e resistência muscular: confiabilidade e predição de uma repetição máxima - Revisão e novas evidências Tests de fuerza y resistencia muscular: confiabilidad de la prediccion de una repeticion máxima - Revision y nuevas evidencias Muscular strength and endurance tests: reliability and prediction of one repetition maximum - Review and new evidences
Marta Inez Rodrigues Pereira
% de 1RM debe ser considerada con mucha cautela.Intra-tester reliability is fundamental in determining the quality of data collected in research. Few controlled studies have reported the reliability of strength tests and, in spite of most published studies reporting it to be good (0.79 to 0.99, differences between test and retest are observed to be statistically significant. Thus, for research purposes, it is suggested that values should be taken from a second test, at least, so that changes in strength may be attributed to treatment effect and not simply to adaptation to the test protocol. The relationships between maximum strength tests and submaximal tests or anthropometric variables have been investigated in order to predict maximal strength without submitting subjects to a maximal load test, so as to avoid the risk of injury. Maximal load, or a percentage of it, is commonly used to better prescribe training. Prediction of one repetition maximum (1RM from submaximal tests seems to be good (in general, correlation coefficients > 0.90, although studies have mostly failed to cross-validate prediction equations. Thus, care should be taken especially in relation to specificity of the population, of the exercise, and performance technique when developing and applying these equations. Anthropometric variables have not proven to be good predictors of 1RM. The number of repetitions for a given % of 1RM is different for different exercises, so is the load for a given number of repetitions maximum (nRM when performed at different velocities. Exercise prescription based, indifferently, on number of repetitions or %1RM should be carefully considered.
Jensen, Bente Rona; Berthelsen, Martin Peter; Husu, Edith
INTRODUCTION: We studied the functional effects of combined strength and aerobic anti-gravity training in severely affected patients with Becker and Limb-Girdle muscular dystrophies. METHODS: Eight patients performed 10-week progressive combined strength (squats, calf raises, lunges) and aerobic...
Força muscular respiratória, postura corporal, intensidade vocal e tempos máximos de fonação na Doença de Parkinson Respiratory muscle strength, body posture, vocal intensity and maximum phonation times in Parkinson Disease
Fernanda Vargas Ferreira
Full Text Available TEMA: Verificar os achados de força muscular respiratória (FMR, postura corporal (PC, intensidade vocal (IV e tempos máximos de fonação (TMF, em indivíduos com Doença de Parkinson (DP e casos de controle, conforme o sexo, o estágio da DP e o nível de atividade física (AF. PROCEDIMENTOS: três homens e duas mulheres com DP, entre 36 e 63 anos (casos de estudo - CE, e cinco indivíduos sem doenças neurológicas, pareados em idade, sexo e nível de AF (casos de controle - CC. Avaliadas a FMR, PC, IV e TMF. RESULTADOS: homens: diminuição mais acentuada dos TMF, IV e FMR nos parkinsonianos, mais alterações posturais nos idosos; mulheres com e sem DP: alterações posturais similares, relação positiva entre estágio, nível de AF e as demais medidas. CONCLUSÕES: Verificou-se nas parkinsonianas, prejuízo na IV e nos parkinsonianos déficits nos TMF, IV e FMR. Sugerem-se novos estudos sob um viés interdisciplinar.PURPOSE: To check the findings on respiratory muscular strength (RMS, body posture (BP, vocal intensity (VI and maximum phonation time (MPT, in patients with Parkinson Disease (PD and control cases, according to gender, Parkinson Disease stage (PD and the level of physical activity (PA. METHODS: three men and two women with PD, between 36 and 63 year old (study cases - SC, and five subjects without neurologic diseases, of the same age, gender and PA level (control cases - CC. We evaluated RMS, BP, VI and MPT. RESULTS: men: a more pronounced decrease of MPT, VI, RMS in Parkinson patients, plus postural alterations in the elderly; women: similar postural alterations, positive relation between stages, PA level and the other measures. CONCLUSIONS: We observed in women with PD, impaired VI; in men with PD deficits in MPT, VI, RMS. We suggest further studies under an interdisciplinary bias.
Baroncelli, A B; Abellonio, F; Pagano, T B; Esposito, I; Peirone, B; Papparella, S; Paciello, O
A 3-year-old, male Labrador retriever dog was presented with clinical signs of progressive exercise intolerance, bilateral elbow extension, rigidity of the forelimbs, hindlimb flexion and kyphosis. Microscopical examination of muscle tissue showed marked variability in myofibre size, replacement of muscle with mature adipose tissue and degeneration/regeneration of muscle fibres, consistent with muscular dystrophy. Immunohistochemical examination for dystrophin showed markedly reduced labelling with monoclonal antibodies specific for the rod domain and the carboxy-terminal of dystrophin, while expression of β-sarcoglycan, γ-sarcoglycan and β-dystroglycan was normal. Immunoblotting revealed a truncated dystrophin protein of approximately 135 kDa. These findings supported a diagnosis of congenital canine muscular dystrophy resembling Becker muscular dystrophy in man. Copyright © 2014 Elsevier Ltd. All rights reserved.
Davison, Michael J; Maly, Monica R; Keir, Peter J; Hapuhennedige, Sandani M; Kron, Amie T; Adachi, Jonathan D; Beattie, Karen A
Thigh lean muscle and intramuscular fat have been implicated in the impairment of physical function observed in people with knee osteoarthritis. We investigated the relationships of quadriceps and hamstrings intramuscular fat fraction and lean muscle volume with muscle power and strength, controlling for neuromuscular activation, and physical performance in women with knee OA. Women (n=20) 55years or older with symptomatic, radiographic knee osteoarthritis underwent a 3.0T magnetic resonance imaging scan of the thigh of their most symptomatic knee. Axial fat-separated images were analyzed using software to quantify intramuscular fat and lean muscle volumes of the quadriceps and hamstrings. To quantify strength and power of the knee extensors and flexors, participants performed maximum voluntary isometric contraction and isotonic knee extensions and flexions, respectively. Electromyography of the quadriceps and hamstrings was measured. Participants also completed five physical performance tests. Quadriceps and hamstrings lean muscle volumes were related to isotonic knee extensor (B=0.624; p=0.017) and flexor (B=1.518; p=0.032) power, but not knee extensor (B=0.001; p=0.615) or flexor (B=0.001; p=0.564) isometric strength. Intramuscular fat fractions were not related to isotonic knee extensor or flexor power, nor isometric strength. No relationships were found between intramuscular fat or lean muscle volume and physical performance. Muscle power may be more sensitive than strength to lean muscle mass in women with knee osteoarthritis. Thigh lean muscle mass, but neither intramuscular nor intermuscular fat, is related to knee extensor and flexor power in women with knee osteoarthritis. Copyright © 2016 Elsevier Ltd. All rights reserved.
Full Text Available Aging sarcopenia and muscular dystrophy are two conditions characterized by lower skeletal muscle quantity, lower muscle strength, and lower physical performance. Aging is associated with a peculiar alteration in body composition called sarcopenic obesity characterized by a decrease in lean body mass and increase in fat mass. To evaluate the presence of sarcopenia and obesity in a cohort of adult patients with muscular dystrophy we have used the measurement techniques considered golden standard for sarcopenia that is for muscle mass dual energy X-ray absorptiometry (DXA, for muscle strength hand held dynamometry, and for physical performance gait speed. The study involved 14 adult patients with different types of muscular dystrophy. We were able to demonstrate that all patient were sarcopenic-obese. We showed in fact that all were sarcopenic based on appendicular lean, fat & bone free, mass index (ALMI. In addition all resulted obese according to the % of body fat determined by DXA in contrast with their body mass index ranging from underweight to obese. Skeletal muscle mass determined by DXA was markedly reduced in all patients and correlated with residual muscle strength determined by hand held dynamometry, and physical performances determined by gait speed and respiratory function. Finally we showed that ALMI was the best linear explicator of muscle strength and physical function. Altogether, our study suggest the relevance of a proper evaluation of body composition in muscular dystrophy and we propose to use, both in research and practice, the measurement techniques that has already been demonstrated effective in aging sarcopenia.
Horikawa, Hirosei; Konagaya, Masaaki; Takayanagi, Tetsuya; Otsuji, Hideaki
We quantitatively evaluated the muscular wastings of lower extremities in Duchenne muscular dystrophy (DMD) by computed tomography (CT). The subjects were 21 cases of DMD (an ambulant case and 20 wheelchair-ridden cases, ages ranging from 10 to 21 years old) and 4 control males. The CT scan was carried out at the mid-level between lesser trochanter and medial condyle of femur and the largest diameter level of lower leg. The density and the cross-sectional area of each muscle were measured on the CT image. The average CT number of normal muscle was varying from 40 to 60, as well as that of fat was -115. Then we calculated CT index of each muscle denoted as follows: CT index = [average CT number of muscle-(-115)] X(cross-sectional area of each muscle). The measurements of muscle strength and serum CK level were performed and their relationships to CT index were examined. The results were achieved as follows: 1) Wheelchair-ridden cases with DMD showed severe decrease in the average CT number and the CT index of each muscle with normal controls. With progression, the average CT number and the CT index were reduced. But gracilis muscle and sartorius muscle were relatively spared in comparison with other muscles. 2) There was positive correlation between the CT index and the muscle strength in triceps surae muscle, hamstrings muslce and quardriceps femoris muscle. 3) The CT index of whole thigh muscles and that of whole lower leg muscles were highly correlated to serum CK level. These results suggest that the quantitative analysis of muscle CT is an useful measurement for assessement of muscular wastings in DMD. (author)
Halliwell, Emma; Dittmar, Helga; Orsborn, Amber
This study examines the effects of exposure to the muscular male body ideal on body-focused negative affect among male gym users and non-exercisers. As hypothesized, the impact of media exposure depended on men's exercise status. Non-exercisers (n = 58) reported greater body-focused negative affect after exposure to images of muscular male models than after neutral images (no model controls), whereas gym users (n = 58) showed a tendency for less body-focused negative affect after the model images than after the control images. Furthermore, the extent to which gym users were motivated to increase strength and muscularity moderated these exposure effects; men who reported stronger strength and muscularity exercise motivation reported a greater degree of self-enhancement after exposure to the muscular ideal. The findings are interpreted with respect to likely differences in motives for social comparisons.
Kim, Jung Jin; Kim, Dong Joo; Kang, Su Tae; Lee, Jang Hwa
Highlights: ► The final goal is to develop a fiber reinforced concrete for containment buildings. ► We investigated the effect of S/a on the bond strength of steel fibers. ► Deformed steel fibers produced much higher interfacial bond strength. ► As S/a increased, twisted fiber showed a significant enhancement in bond strength. ► Smooth and hooked fiber showed no clear difference as S/a increased. - Abstract: The interfacial bond strength of three high strength steel fibers (smooth, hooked, and twisted fiber) in concrete of nuclear power plants was investigated to develop fiber reinforced concrete for containment building. Sand to aggregate ratio (S/a) was adjusted to compensate reduction in the workability due to adding fibers; the influence of S/a ratio on the interfacial bond strength was investigated. As the S/a ratio increased from 0.444 to 0.615, the bond strength of twisted steel fiber was significantly improved while smooth and hooked steel fiber showed no clear difference. The different sensitivity according to the S/a ratio results from the different pullout mechanism: twisted steel fiber generates more mechanical interaction during fiber pullout at the interface between fiber and matrix than smooth and hooked fibers. The microscopic observation by scanning electron microscope back-scattered electrons images discovered lower porosity at the interfacial transition zone between fiber and concrete with higher S/a ratio.
Adigüzel, Niyazi Sidki; Günay, Mehmet
The purpose of this study was to investigate the effect of eight weeks plyometric training on anaerobic power, counter movement jumping and isokinetic strength in 15-18 years aged basketball players. This study was including 30 male Basketball players. The subjects were divided into two groups as: the experimental group (n = 15) and the control…
Feasibility of protein-sparing modified fast by tube (ProMoFasT) in obesity treatment: a phase II pilot trial on clinical safety and efficacy (appetite control, body composition, muscular strength, metabolic pattern, pulmonary function test).
Sukkar, S G; Signori, A; Borrini, C; Barisione, G; Ivaldi, C; Romeo, C; Gradaschi, R; Machello, N; Nanetti, E; Vaccaro, A L
Anecdotal data in the last few years suggest that protein-sparing modified diet (PSMF) delivered by naso-gastric tube enteral (with continuous feeding) could attain an significant weight loss and control of appetite oral feeding, but no phase II studies on safety and efficacy have been done up to now. To verify the safety and efficacy of a protein-sparing modified fast administered by naso-gastric tube (ProMoFasT) for 10 days followed by 20 days of a low-calorie diet, in patients with morbid obesity (appetite control, fat free mass maintenance, pulmonary function tests and metabolic pattern, side effects), 26 patients with a BMI ≥30 kg/m 2 have been selected. The patients had to follow a protein-sparing fast by enteral nutrition (ProMoFasT) for 24 h/day, for 10 days followed by 20 days of low-calorie diet (LCD). The endpoint was represented by body weight, BMI, abdominal circumference, Haber's appetite test, body composition by body impedance assessment (BIA), handgrip strength test, metabolic pattern, pulmonary function test. Safety was assessed by evaluation of complications and side effects of PSMF and/or enteral nutrition. In this report the results on safety and efficacy are described after 10 and 30 days of treatment. After the recruiting phase, a total of 22 patients out of 26 enrolled [14 (63.6 %) females] were evaluated in this study. Globally almost all clinical parameters changed significantly during first 10 days. Total body weight significantly decreased after 10 days (∆-6.1 ± 2; p < 0.001) and this decrease is maintained in the following 20 days of LCD (∆ = -5.88 ± 1.79; p < 0.001). Also the abdominal circumference significantly decreased after 10 days [median (range): -4.5 (-30 to 0); p < 0.001] maintained then in the following 20 days of LCD [median (range) = -7 (-23.5 to -2); p < 0.001]. All BIA parameters significantly changed after 10 and 30 days from baseline. All parameters except BF had a significant
Diaz-Lara, Francisco Javier; Del Coso, Juan; García, Jose Manuel; Portillo, Luis J; Areces, Francisco; Abián-Vicén, Javier
Scientific information about the effects of caffeine intake on combat sport performance is scarce and controversial. The aim of this study was to investigate the effectiveness of caffeine to improve Brazilian Jiu-jitsu (BJJ)-specific muscular performance. Fourteen male and elite BJJ athletes (29.2 ± 3.3 years; 71.3 ± 9.1 kg) participated in a randomized double-blind, placebo-controlled and crossover experiment. In two different sessions, BJJ athletes ingested 3 mg kg(-1) of caffeine or a placebo. After 60 min, they performed a handgrip maximal force test, a countermovement jump, a maximal static lift test and bench-press tests consisting of one-repetition maximum, power-load, and repetitions to failure. In comparison to the placebo, the ingestion of the caffeine increased: hand grip force in both hands (50.9 ± 2.9 vs. 53.3 ± 3.1 kg; respectively p caffeine also increased the one-repetition maximum (90.5 ± 7.7 vs. 93.3 ± 7.5 kg; p = .02), maximal power obtained during the power-load test (750.5 ± 154.7 vs. 826.9 ± 163.7 W; p caffeine increased dynamic and isometric muscular force, power, and endurance strength in elite BJJ athletes. Thus, caffeine might be an effective ergogenic aid to improve physical performance in BJJ.
Andersen, H; Gadeberg, P C; Brock, B
Diabetic patients with polyneuropathy develop motor dysfunction. To establish whether motor dysfunction is associated with muscular atrophy the ankle dorsal and plantar flexors of the non-dominant leg were evaluated with magnetic resonance imaging in 8 patients with symptomatic neuropathy, in 8 non...... confirmed that the atrophy predominated distally. We conclude that muscular atrophy underlies motor weakness at the ankle in diabetic patients with polyneuropathy and that the atrophy is most pronounced in distal muscles of the lower leg indicating that a length dependent neuropathic process explains...
Martín Martín, Laura
Fundamentos: Cada vez son más las personas que realizan algún tipo de actividad física, pero pocas son las que poseen un verdadero conocimiento de los procesos que se desencadenan a nivel muscular y la influencia de la alimentación en la misma. El objetivo de este trabajo es ofrecer información de manera general sobre el metabolismo muscular. Métodos: Revisión bibliográfica de artículos y documentos consultando bases de datos y libros. La mayor parte del análisis ha sido ext...
... difficulty breathing. Children with this type often have joint deformities (contractures) that impair movement. In severe cases, ... Proximal spinal muscular atrophy Washington University, St. Louis: Neuromuscular Disease Center: Spinal Muscular Atrophy Patient Support and ...
Wohlgemuth, M.; Horlings, G.C.; Kooi, E.L. van der; Gilhuis, H.J.; Hendriks, J.C.M.; Maarel, S.M. van der; Engelen, B.G.M. van; Heijdra, Y.F.; Padberg, G.W.A.M.
To test the hypothesis that wheelchair dependency and (kypho-)scoliosis are risk factors for developing respiratory insufficiency in facioscapulohumeral muscular dystrophy, we examined 81 patients with facioscapulohumeral muscular dystrophy 1 of varying degrees of severity ranging from ambulatory
... muscular dystrophy? There are more than 30 forms of muscular dystrophy (MD), with information on the primary types included in the table below. 1 Duchenne (DMD) What It Is Common Symptoms How It ...
Pallarés, J G; Martínez-Abellán, A; López-Gullón, J M; Morán-Navarro, R; De la Cruz-Sánchez, E; Mora-Rodríguez, R
It is habitual for combat sports athletes to lose weight rapidly to get into a lower weight class. Fluid restriction, dehydration by sweating (sauna or exercise) and the use of diuretics are among the most recurrent means of weight cutting. Although it is difficult to dissuade athletes from this practice due to the possible negative effect of severe dehydration on their health, athletes may be receptive to avoid weight cutting if there is evidence that it could affect their muscle performance. Therefore, the purpose of the present study was to investigate if hypohydration, to reach a weight category, affects neuromuscular performance and combat sports competition results. We tested 163 (124 men and 39 woman) combat sports athletes during the 2013 senior Spanish National Championships. Body mass and urine osmolality (UOSM) were measured at the official weigh-in (PRE) and 13-18 h later, right before competing (POST). Athletes were divided according to their USOM at PRE in euhydrated (EUH; UOSM 250-700 mOsm · kgH2O(-1)), hypohydrated (HYP; UOSM 701-1080 mOsm · kgH2O(-1)) and severely hypohydrated (S-HYP; UOSM 1081-1500 mOsm · kgH2O(-1)). Athletes' muscle strength, power output and contraction velocity were measured in upper (bench press and grip) and lower body (countermovement jump - CMJ) muscle actions at PRE and POST time-points. At weigh-in 84 % of the participants were hypohydrated. Before competition (POST) UOSM in S-HYP and HYP decreased but did not reach euhydration levels. However, this partial rehydration increased bench press contraction velocity (2.8-7.3 %; p < 0.05) and CMJ power (2.8 %; p < 0.05) in S-HYP. Sixty-three percent of the participants competed with a body mass above their previous day's weight category and 70 of them (69 % of that sample) obtained a medal. Hypohydration is highly prevalent among combat sports athletes at weigh-in and not fully reversed in the 13-18 h from weigh-in to competition. Nonetheless, partial rehydration recovers
McMaster, Daniel Travis; Gill, Nicholas; Cronin, John; McGuigan, Michael
Strength and power are crucial components to excelling in all contact sports; and understanding how a player's strength and power levels fluctuate in response to various resistance training loads is of great interest, as it will inevitably dictate the loading parameters throughout a competitive season. This is a systematic review of training, maintenance and detraining studies, focusing on the development, retention and decay rates of strength and power measures in elite rugby union, rugby league and American football players. A literature search using MEDLINE, EBSCO Host, Google Scholar, IngentaConnect, Ovid LWW, ProQuest Central, ScienceDirect Journals, SPORTDiscus and Wiley InterScience was conducted. References were also identified from other review articles and relevant textbooks. From 300 articles, 27 met the inclusion criteria and were retained for further analysis. STUDY QUALITY: Study quality was assessed via a modified 20-point scale created to evaluate research conducted in athletic-based training environments. The mean ± standard deviation (SD) quality rating of the included studies was 16.2 ± 1.9; the rating system revealed that the quality of future studies can be improved by randomly allocating subjects to training groups, providing greater description and detail of the interventions, and including control groups where possible. Percent change, effect size (ES = [Post-Xmean - Pre-Xmean)/Pre-SD) calculations and SDs were used to assess the magnitude and spread of strength and power changes in the included studies. The studies were grouped according to (1) mean intensity relative volume (IRV = sets × repetitions × intensity; (2) weekly training frequency per muscle group; and (3) detraining duration. IRV is the product of the number of sets, repetitions and intensity performed during a training set and session. The effects of weekly training frequencies were assessed by normalizing the percent change values to represent the weekly changes in
Full Text Available Abstract Background It is well documented that both balance and resistance training have the potential to mitigate intrinsic fall risk factors in older adults. However, knowledge about the effects of simultaneously executed balance and resistance training (i.e., resistance training conducted on unstable surfaces [URT] on lower-extremity muscle strength, power and balance in older adults is insufficient. The objective of the present study was to compare the effects of machine-based stable resistance training (M-SRT and two types of URT, i.e., machine-based (M-URT and free-weight URT (F-URT, on measures of lower-extremity muscle strength, power and balance in older adults. Methods Seventy-five healthy community-dwelling older adults aged 65–80 years, were assigned to three intervention groups: M-SRT, M-URT and F-URT. Over a period of ten weeks, all participants exercised two times per week with each session lasting ~60 min. Tests included assessment of leg muscle strength (e.g., maximal isometric leg extension strength, power (e.g., chair rise test and balance (e.g., functional reach test, carried out before and after the training period. Furthermore, maximal training load of the squat-movement was assessed during the last training week. Results Maximal training load of the squat-movement was significantly lower in F-URT in comparison to M-SRT and M-URT. However, lower-extremity resistance training conducted on even and uneven surfaces meaningfully improved proxies of strength, power and balance in all groups. M-URT produced the greatest improvements in leg extension strength and F-URT in the chair rise test and functional reach test. Conclusion Aside from two interaction effects, overall improvements in measures of lower-extremity muscle strength, power and balance were similar across training groups. Importantly, F-URT produced similar results with considerably lower training load as compared to M-SRT and M-URT. Concluding, F-URT seems an
It is well documented that both balance and resistance training have the potential to mitigate intrinsic fall risk factors in older adults. However, knowledge about the effects of simultaneously executed balance and resistance training (i.e., resistance training conducted on unstable surfaces [URT]) on lower-extremity muscle strength, power and balance in older adults is insufficient. The objective of the present study was to compare the effects of machine-based stable resistance training (M-SRT) and two types of URT, i.e., machine-based (M-URT) and free-weight URT (F-URT), on measures of lower-extremity muscle strength, power and balance in older adults. Seventy-five healthy community-dwelling older adults aged 65-80 years, were assigned to three intervention groups: M-SRT, M-URT and F-URT. Over a period of ten weeks, all participants exercised two times per week with each session lasting ~60 min. Tests included assessment of leg muscle strength (e.g., maximal isometric leg extension strength), power (e.g., chair rise test) and balance (e.g., functional reach test), carried out before and after the training period. Furthermore, maximal training load of the squat-movement was assessed during the last training week. Maximal training load of the squat-movement was significantly lower in F-URT in comparison to M-SRT and M-URT. However, lower-extremity resistance training conducted on even and uneven surfaces meaningfully improved proxies of strength, power and balance in all groups. M-URT produced the greatest improvements in leg extension strength and F-URT in the chair rise test and functional reach test. Aside from two interaction effects, overall improvements in measures of lower-extremity muscle strength, power and balance were similar across training groups. Importantly, F-URT produced similar results with considerably lower training load as compared to M-SRT and M-URT. Concluding, F-URT seems an effective and safe alternative training program to mitigate
Far Saeed Jamshidi
Full Text Available Purpose : The purpose of this study describes the results of a survey of the practices of Iranian Wrestling League strength and conditioning (IWL S&C coaches. Material: The response rate was 88.5% (100 of 113. The contents survey examines include: (a background information, (b physical testing, (c flexibility development, (d speed development, (e plyometrics, (f strength/power development, (g unique aspects, and (h comments from coaches providing additional information. Results: Results indicate, in part, that coaches assess an average of 7.3 parameters of fitness, with tests speed being the most common. All coaches used a variety of flexibility development strategies. Results reveal that all of IWL S&C coaches follow a periodization model. Speed as the first priority (100% and muscular endurance, power and strength as second priority (97% of importance in evaluating their athletes. Sixty-six percent coaches (66% indicated that their athletes used Olympic-style lifts. All coaches employed plyometric exercises with their athletes. Ninety-two percent (92% of the coaches reported that used plyometric trainings for increasing the speed of their wrestlers and 82% of the coaches used plyometric jump in place exercises as regular practice in their trainings. Conclusions: The squat and its variations, as well as the Olympic-style lifts and their variations, were the most frequently used exercises. The survey serves as a review and a source of applied information and new ideas.
Wohlgemuth, M.; Swart, B.J.M. de; Kalf, J.G.; Joosten, F.B.M.; Vliet, A.M. van der; Padberg, G.W.A.M.
Dysphagia is not considered a symptom of facioscapulohumeral muscular dystrophy (FSHD). In this study, the authors found that dysphagia does occur in patients with advanced FSHD showing mild involvement of the jaw and lingual muscles. Dysphagia is seldom life threatening in these patients. The
J Gordon Millichap
Full Text Available Investigators at the Dubowitz Neuromuscular Centre, Great Ormond Street Hospital, and other centers in the UK, conducted a prospective longitudinal study across 17 neuromuscular centers in the UK of 360 boys aged 3-15 years with Duchenne muscular dystrophy who were treated with daily or intermittent (10 days on/10 days off prednisolone for a mean duration of 4 years.
Full Text Available Muscularity is a potential indicator for the selection of more productive cattle. Mapping quantitative trait loci (QTL for traits related to muscularity is useful to identify the genomic regions where the genes affecting muscularity reside. QTL analysis from a Limousin-Jersey double backcross herd was conducted using QTL Express software with cohort and breed as the fixed effects. Nine QTL suggested to have an association with muscularity were identified on cattle chromosomes BTA 1, 2, 3, 4, 5, 8, 12, 14 and 17. The myostatin gene is located at the centromeric end of chromosome 2 and not surprisingly, the Limousin myostatin F94L variant accounted for the QTL on BTA2. However, when the myostatin F94L genotype was included as an additional fixed effect, the QTL on BTA17 was also no longer significant. This result suggests that there may be gene(s that have epistatic effects with myostatin located on cattle chromosome 17. Based on the position of the QTL in base pairs, all the genes that reside in the region were determined using the Ensembl data base (www.ensembl.org. There were two potential candidate genes residing within these QTL regions were selected. They were Smad nuclear interacting protein 1 (SNIP1 and similar to follistatin-like 5 (FSTL5. (JIIPB 2010 Vol 20 No 1: 1-10
Cardamone, Michael; Darras, Basil T.; Ryan, Monique M.
The inherited myopathies and muscular dystrophies are a diverse group of muscle diseases presenting with common complaints and physical signs: weakness, motor delay, and respiratory and bulbar dysfunction. The myopathies are caused by genetic defects in the contractile apparatus of muscle, and
Effects of an aquatic versus non-aquatic respiratory exercise program on the respiratory muscle strength in healthy aged persons Efeitos de um programa de cinesioterapia respiratória desenvolvido em dois meios diferentes - aquático e solo - na força muscular respiratória de idosos saudáveis
Maiza Ritomy Ide
Full Text Available Aging of the worldwide population is a concern of most governmental entities, spanning practically all areas of prevention and rehabilitation. Aging leads to physiological alterations that result in adverse social and financial effects. There is a trend to emphasize prevention, which is less expensive and socially more desirable than therapeutic intervention. PURPOSE: To assess the effect of a program of aquatic versus non-aquatic respiratory exercises on respiratory muscle strength in healthy aged persons. METHODS: The respiratory muscle strength was measured in 81 subjects between 60 and 65 years, 59 of which completed the program. Subjects were randomized into 3 groups. Gaquatic undertook a program of respiratory exercise in an aquatic environment. Gnon-aquatic undertook the same program in a non-aquatic environment. Gcontrol acted as the negative control. Programs were applied three times a week for 10 consecutive weeks. Subsequently, subjects were reevaluated, and results compared to each individual's pre-treatment own result and between the groups. The data were statistically analyzed using the paired t test and the Sign test. Comparisons between the groups were performed through parametric and nonparametric variance. A comparison of Gaquatic and Gnon-aquatic versus Gcontrol was performed using the Dunnett test. RESULTS: A significant improvement in the inspiratory muscle strength in the Gaquatic group compared to the Gcontrol, group was found, suggesting beneficial effects mediated by the aquatic exercise. The expiratory muscles did not show significant alterations. CONCLUSION: Aquatic respiratory exercise improves the inspiratory muscle strength of healthy aged persons. However, neither aquatic nor non-aquatic respiratory exercise influences the expiratory muscle strength.O envelhecimento da população mundial é uma preocupação para grande parte das entidades governamentais. Acarreta alterações fisiológicas em todo o organismo e
Thomas, Adam; Tod, David A; Edwards, Christian J; McGuigan, Michael R
This study examined the mediating role of drive for muscularity and social physique anxiety (SPA) in the perceived muscular male ideal physique and muscle dysmorphia relationship in weight training men. Men (N = 146, mean ± SD; age, 22.8 ± 5.0 years; weight, 82.0 ± 11.1 kg; height, 1.80 ± 0.07 m; body mass index, 25.1 ± 3.0) who participated in weight training completed validated questionnaires measuring drive for muscularity, SPA, perceived muscular male ideal physique, global muscle dysmorphia, and several characteristics of muscle dysmorphia (exercise dependence, diet manipulation, concerns about size/symmetry, physique protection behavior, and supplementation). Perceived ideal physique was an independent predictor of muscle dysmorphia measures except physique protection (coefficients = 0.113-0.149, p ≤ 0.05). Perceived ideal physique also predicted muscle dysmorphia characteristics (except physique protection and diet) through the indirect drive for muscularity pathway (coefficients = 0.055-0.116, p ≤ 0.05). Perceived ideal physique also predicted size/symmetry concerns and physique protection through the indirect drive for muscularity and SPA pathway (coefficients = 0.080-0.025, p ≤ 0.05). These results extend current research by providing insights into the way correlates of muscle dysmorphia interact to predict the condition. The results also highlight signs (e.g., anxiety about muscularity) that strength and conditioning coaches can use to identify at-risk people who may benefit from being referred for psychological assistance.
Efeitos da crioterapia e facilitação neuromuscular proprioceptiva sobre a força muscular nas musculaturas flexora e extensora de joelho Effects of cryotherapy and proprioceptive neuromuscular facilitation on muscle strength at the flexor and extensor muscles of the knee
Daiana Moreira Mortari
Full Text Available As musculaturas flexora e extensora do joelho são freqüentemente lesionadas devido a um desequilíbrio entre esses grupos. Recursos térmicos, como a crioterapia, e técnicas de alongamento, como a técnica mantém-relaxa da facilitação neuromuscular proprioceptiva (FNP, influenciam a flexibilidade e força muscular, proporcionando maior homogeneidade entre essas musculaturas e diminuindo a incidência de lesões. Este estudo objetivou verificar os efeitos da crioterapia e da FNP sobre a força das musculaturas flexora e extensora de joelho. A amostra foi composta por 18 mulheres com idade entre 18 e 24 anos, não-praticantes de atividade física regular, divididas em dois grupos: um submetido a crioterapia e o outro à técnica mantém-relaxa da FNP. Antes e após uma sessão de aplicação das técnicas foi feita avaliação isocinética. A aplicação da técnica mantém-relaxa provocou aumento da força em ambas as musculaturas em ambos os membros, atingindo nível de significância nos flexores do membro inferior direito (p=0,04. A crioterapia diminuiu a força dos extensores e exerceu efeito contrário sobre os flexores, tendo gerado aumento significativo nos flexores do membro inferior direito (p=0,035. Quando comparadas as técnicas, a técnica mantém-relaxa gerou maiores valores de pico de torque, principalmente nos extensores do membro inferior esquerdo (p=0,042. Conclui-se que a técnica mantém-relaxa da FNP gerou maiores valores no pico de torque em relação à crioterapia.Knee extensor and flexor muscles are often injured due to an imbalance between these groups, which may lead to a deficit in muscle performance. Thermal resources, such as cryotherapy, and stretching techniques, such as the "hold-relax" of proprioceptive neuromuscular facilitation (PNF, influence flexibility and muscle strength and may reduce the chances of muscle tendon injuries. The aim of the study was to verify the effects of cryotherapy and of the PNF
Roemers, P; Mazzola, P N; De Deyn, P P; Bossers, W J; van Heuvelen, M J G; van der Zee, E A
BACKGROUND: Voluntary strength training methods for rodents are necessary to investigate the effects of strength training on cognition and the brain. However, few voluntary methods are available. NEW METHOD: The current study tested functional and muscular effects of two novel voluntary strength
Rubini, Alessandro; Rizzato, Alex; Fava, Simone; Olivato, Nicola; Mangar, Devanand; Camporesi, Enrico M; Bosco, Gerardo
An increased sympathetic activity during muscular effort is a well established physiological response, whose intensity is known to increase with the muscular load. Spirometry was described to improve as an effect of swimming training in healthy and asthmatic subjects, suggesting a decrease in airway resistance The aim was to investigate the possible effect of muscular exercise (swimming) on spirometry, in particular searching for possible differences because of different swimming times. The measurements were performed on 9 highly trained male competitive swimmers (age: 41±12.79 years, height: 1.69±0.06 meters, weight: 66.14±14.28 kg, BMI: 22.8±3.61 kg/m2) during an official competition. The data were collected at the border of the swimming-pool before (control, C) and few minutes after the swimming sessions (exercise, E), which consisted either of 800 meter (7 subjects) or 1500 meter (5 subjects) free style. A general trend indicating a postexercise increase in spirometry was observed. We found post-exercise significant increments in FEV1 and in MEF75 for both the 800 and 1500 meter swimming sessions, and in FEF25-75 and in MEF25 for the shorter distance. We conclude that, as it may be expected, muscular exercise induces an improvement of spirometry both because of a smooth muscle relaxation-induced modulation of airway diameter and resistance to airflow, and because of an enhanced expiratory muscle contraction strength. Both of these mechanisms are related to an increased sympathetic activity which is well known to accompany muscular exercise.
Smith, Derek T; Judge, Stacey; Malone, Ashley; Moynes, Rebecca C; Conviser, Jason; Skinner, James S
Reduced strength, balance, and functional independence diminish quality of life and increase health care costs. Sixty adults (82.2 ± 4.9 years) were randomized to a control or three 12-week intervention groups: bioDensity (bD); Power Plate (PP) whole-body vibration (WBV); or bD+PP. bD involved one weekly 5-s maximal contraction of four muscle groups. PP involved two 5-min WBV sessions. Primary outcomes were strength, balance, and Functional Independence Measure (FIM). No groups differed initially. Strength significantly increased 22-51% for three muscle groups in bD and bD+PP (P Balance significantly improved in PP and bD+PP but not in control or bD. bD, PP, and bD+PP differentially improved FIM self-care and mobility. Strength improvements from weekly 5-min sessions of bD may impart health/clinical benefits. Balance and leg strength improvements suggest WBV beneficially impacts fall risk and incidence. Improved FIM scores are encouraging and justify larger controlled trials on bD and bD+PP efficacy.
Kim, Jung Jin, E-mail: email@example.com [Department of Civil and Environmental Engineering, SeJong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Kim, Dong Joo, E-mail: firstname.lastname@example.org [Department of Civil and Environmental Engineering, SeJong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747 (Korea, Republic of); Kang, Su Tae, E-mail: email@example.com [Department of Civil Engineering, Daegu University, 201 Daegudae-ro, Jillyang, Gyeongsan, Gyeongbuk 712-714 (Korea, Republic of); Lee, Jang Hwa, E-mail: firstname.lastname@example.org [Korea Institute of Construction Technology, 2311 Daewha-Dong, Ilsan-Gu, Goyang-Si, Gyeonggi-Do 411-712 (Korea, Republic of)
Highlights: Black-Right-Pointing-Pointer The final goal is to develop a fiber reinforced concrete for containment buildings. Black-Right-Pointing-Pointer We investigated the effect of S/a on the bond strength of steel fibers. Black-Right-Pointing-Pointer Deformed steel fibers produced much higher interfacial bond strength. Black-Right-Pointing-Pointer As S/a increased, twisted fiber showed a significant enhancement in bond strength. Black-Right-Pointing-Pointer Smooth and hooked fiber showed no clear difference as S/a increased. - Abstract: The interfacial bond strength of three high strength steel fibers (smooth, hooked, and twisted fiber) in concrete of nuclear power plants was investigated to develop fiber reinforced concrete for containment building. Sand to aggregate ratio (S/a) was adjusted to compensate reduction in the workability due to adding fibers; the influence of S/a ratio on the interfacial bond strength was investigated. As the S/a ratio increased from 0.444 to 0.615, the bond strength of twisted steel fiber was significantly improved while smooth and hooked steel fiber showed no clear difference. The different sensitivity according to the S/a ratio results from the different pullout mechanism: twisted steel fiber generates more mechanical interaction during fiber pullout at the interface between fiber and matrix than smooth and hooked fibers. The microscopic observation by scanning electron microscope back-scattered electrons images discovered lower porosity at the interfacial transition zone between fiber and concrete with higher S/a ratio.
Tornøe, Birte; Andersen, Lars L; Skotte, J H
Frequent or chronic tension-type headache in children is a prevalent and debilitating condition for the child, often leading to medication overuse. To explore the relationship between physical factors and tension-type headache in children, the quality of repeated measures was examined. The aim of...... of the present study was to determine the test-retest repeatability of parameters determining isometric neck and shoulder strength and stability, aerobic power, and pericranial tenderness in children....
Tornoe, Birte; Andersen, Lars L; Skotte, Jørgen H
BACKGROUND: Tension-type headaches (TTH) are common among children worldwide and mean a potential risk of disability and medication overuse headache. The associated mechanisms, however, remain unsolved. Our study investigated muscle strength in the neck-shoulder region, aerobic power and pericran......BACKGROUND: Tension-type headaches (TTH) are common among children worldwide and mean a potential risk of disability and medication overuse headache. The associated mechanisms, however, remain unsolved. Our study investigated muscle strength in the neck-shoulder region, aerobic power...... and pericranial tenderness in girls with TTH compared with healthy controls. METHODS: A blinded case-control study comprising 41 girls with TTH and 41 age-matched healthy controls. Standardised testing of isometric maximal voluntary contraction (MVC) and force steadiness of neck flexion and extension, as well.......3 (95% CI 1.0-1.6) and 5.2 (95% CI: 1.4-19.6) for each unit of decrease in VO2 max. CONCLUSIONS: Reduced neck-shoulder strength and aerobic power together with increased pericranial tenderness are associated with TTH in girls. Future interventions should be directed towards health promoting patient...
Pérez-Bey, Alejandro; Segura-Jiménez, Víctor; Fernández-Santos, Jorge Del Rosario; Esteban-Cornejo, Irene; Gómez-Martínez, Sonia; Veiga, Oscar L; Marcos, Ascensión; Castro-Piñero, José
To test the associations of muscular fitness and body mass index (BMI), individually and combined, with clustered cardiovascular disease risk factors in children and adolescents and to analyze the mediator role of BMI in the association between muscular fitness and clustered cardiovascular disease risk factors. In total, 239 children (113 girls) and 270 adolescents (128 girls) participated in this cross-sectional study. Height and weight were assessed, and BMI was calculated. A cardiovascular disease risk factors index (CVDRF-I) was created from the combination of the following variables: waist circumference, systolic blood pressure, triglycerides, high-density lipoprotein cholesterol, and glucose. Handgrip strength/weight and standing long jump tests were used to assess muscular fitness. A muscular fitness index was computed from the combination of both tests. Muscular fitness index was associated with CVDRF-I in children of both sexes and adolescent boys; however, these associations disappeared after accounting for BMI. BMI was associated with CVDRF-I in both children and adolescents, even after adjusting for muscular fitness (all P < .001). In male and female children and in adolescent boys, the association between muscular fitness and CVDRF-I was mediated by BMI (all P < .001). Because there was no association between muscular fitness and CVDRF-I in adolescent girls, the mediation hypothesis was discarded. BMI is an independent predictor of CVDRF-I in children and adolescents of both sexes. Conversely, the effect of muscular fitness on CVDRF-I seems to be fully mediated by BMI levels in male and female children and in adolescent boys. Copyright © 2018 Elsevier Inc. All rights reserved.
Kalyani, Rita Rastogi; Tra, Yolande; Yeh, Hsin-Chieh; Egan, Josephine M; Ferrucci, Luigi; Brancati, Frederick L
To examine the independent association between diabetes mellitus (and its duration and severity) and quadriceps strength, quadriceps power, and gait speed in a national population of older adults. Cross-sectional nationally representative survey. United States. Two thousand five hundred seventy-three adults aged 50 and older in the National Health and Nutrition Examination Survey 1999-2002 who had assessment of quadriceps strength. Diabetes mellitus was ascertained according to questionnaire. Measurement of isokinetic knee extensor (quadriceps) strength was performed at 60º/s. Gait speed was assessed using a 20-foot walk test. Multiple linear regression analyses were used to assess the association between diabetes mellitus status and outcomes, adjusting for potential confounders or mediators. Older U.S. adults with diabetes mellitus had significantly slower gait speed (0.96 ± 0.02 m/s) than those without (1.08 ± 0.01 m/s; P diabetes mellitus was also associated with significantly lower quadriceps strength (-4.6 ± 1.9 Nm; P = .02) and power (-4.9 ± 2.0 W; P = .02) and slower gait speed (-0.05 ± 0.02 m/s; P = .002). Associations remained significant after adjusting for physical activity and C-reactive protein. After accounting for comorbidities (cardiovascular disease, peripheral neuropathy, amputation, cancer, arthritis, fracture, chronic obstructive pulmonary disease), diabetes mellitus was independently associated only with gait speed (-0.04 ± 0.02 m/s; P = .02). Diabetes mellitus duration in men and women was negatively associated with age-adjusted quadriceps strength (-5.7 and -3.5 Nm/decade of diabetes mellitus, respectively) and power (-6.1 and -3.8 W/decade of diabetes mellitus, respectively) (all P ≤ .001, no significant interactions according to sex). Glycosylated hemoglobin was not associated with outcomes after accounting for body weight. Older U.S. adults with diabetes mellitus have lower quadriceps strength and quadriceps power that is related
CT scans of muscles in patients with limb girdle type (LG), myotonic type (MYD) and Duchenne type (DMD) dystrophies were obtained at five different body levels: the neck, L3 vertebral body, pelvic girdle, thigh and lower leg. CT numbers, cross sectional areas (CSA) and %CSA of muscle or fat were evaluated in each muscle. The characteristic CT patterns for each type of muscular dystrophy were obtained. Compared with DMD, the gracilis and soleus were more severely damaged in LG and the biceps femoris remained relatively preserved among the hamstrings. In addition, the multifidus of the neck and sternocleidomastoid also were more severely damaged in MYD. This study suggests that CT scan will be useful in the differential diagnosis of these types of muscular dystrophy as well as in planning appropriate rehabilitation and detecting damaged muscles. (author)
Muscular Dystrophies; Muscular Dystrophy, Duchenne; Muscular Disorders, Atrophic; Muscular Diseases; Neuromuscular Diseases; Nervous System Diseases; Genetic Diseases, X-Linked; Genetic Diseases, Inborn
赵年生; 马继政; 程广振
Strength training has become one of the most popular physical activities for increasing characteristics such as absolute muscular strength,endurance,hypertrophy and muscular power.Strength training is broken down into five disciplines：basic strength or resistance training,bodybuilding,power lifting,style-dependant strength sports,and Olympic-style weightlifting.Each style has its own principal injuries,both acute and chronic,related to the individual technique.It is important to know basic rules,common injuries involved in strength training either as their primary or secondary activity on how to prevent injuries related to the sport.%力量训练是体能训练中最受欢迎的运动方式之一,有利于提高肌肉的力量、耐力、肥大程度和爆发力。力量训练可分为5种类型：基础力量训练、健美、爆发举、力量性项目和举重。每种类型力量训练有着特定急性和慢性损伤,和运动技术相关。了解力量训练中常见的损伤、基本原理有助于预防和治疗力量训练的相关损伤。
Gschwind, Yves J; Kressig, Reto W; Lacroix, Andre; Muehlbauer, Thomas; Pfenninger, Barbara; Granacher, Urs
With increasing age neuromuscular deficits (e.g., sarcopenia) may result in impaired physical performance and an increased risk for falls. Prominent intrinsic fall-risk factors are age-related decreases in balance and strength / power performance as well as cognitive decline. Additional studies are needed to develop specifically tailored exercise programs for older adults that can easily be implemented into clinical practice. Thus, the objective of the present trial is to assess the effects of a fall prevention program that was developed by an interdisciplinary expert panel on measures of balance, strength / power, body composition, cognition, psychosocial well-being, and falls self-efficacy in healthy older adults. Additionally, the time-related effects of detraining are tested. Healthy old people (n = 54) between the age of 65 to 80 years will participate in this trial. The testing protocol comprises tests for the assessment of static / dynamic steady-state balance (i.e., Sharpened Romberg Test, instrumented gait analysis), proactive balance (i.e., Functional Reach Test; Timed Up and Go Test), reactive balance (i.e., perturbation test during bipedal stance; Push and Release Test), strength (i.e., hand grip strength test; Chair Stand Test), and power (i.e., Stair Climb Power Test; countermovement jump). Further, body composition will be analysed using a bioelectrical impedance analysis system. In addition, questionnaires for the assessment of psychosocial (i.e., World Health Organisation Quality of Life Assessment-Bref), cognitive (i.e., Mini Mental State Examination), and fall risk determinants (i.e., Fall Efficacy Scale - International) will be included in the study protocol. Participants will be randomized into two intervention groups or the control / waiting group. After baseline measures, participants in the intervention groups will conduct a 12-week balance and strength / power exercise intervention 3 times per week, with each training session lasting 30 min
Amaral, Josária F.; Alvim, Felipe C.; Castro, Eliane A.; Doimo, Leonice A.; Silva, Marcus V.; Novo, José M.
Background Aging is a multifactorial process that leads to changes in the quantity and quality of skeletal muscle and contributes to decreased levels of muscle strength. Objective This study sought to investigate whether the isometric muscle strength, fat-free mass (FFM) and power of the electromyographic (EMG) signal of the upper and lower limbs of women are similarly affected by aging. Method The sample consisted of 63 women, who were subdivided into three groups (young (YO) n=33, 24.7±3.5 years; middle age (MA) n=15, 58.6±4.2 years; and older adults (OA). n=15, 72.0±4.2 years). Isometric strength was recorded simultaneously with the capture of the electrical activity of the flexor muscles of the fingers and the vastus lateralis during handgrip and knee extension tests, respectively. FFM was assessed using dual-energy X-ray absorptiometry. Results The handgrip strength measurements were similar among groups (p=0.523), whereas the FFM of the upper limbs was lower in group OA compared to group YO (p=0.108). The RMSn values of the hand flexors were similar among groups (p=0.754). However, the strength of the knee extensors, the FFM of the lower limbs and the RMSn values of the vastus lateralis were lower in groups MA (p=0.014, p=0.006 and p=0.013, respectively) and OA (p=0.000, p=0.000 and pisometric muscle strength in MLG and electromyographic activity of the lower limbs are more pronounced with the aging process of the upper limb. PMID:24676705
Muehlbauer, Thomas; Gollhofer, Albert; Granacher, Urs
It has frequently been reported that balance and lower-extremity muscle strength/power are associated with sports-related and everyday activities. Knowledge about the relationship between balance, strength, and power are important for the identification of at-risk individuals because deficits in these neuromuscular components are associated with an increased risk of sustaining injuries and falls. In addition, this knowledge is of high relevance for the development of specifically tailored health and skill-related exercise programs. The objectives of this systematic literature review and meta-analysis were to characterize and, if possible, quantify associations between variables of balance and lower-extremity muscle strength/power in healthy individuals across the lifespan. A computerized systematic literature search was performed in the electronic databases PubMed, Web of Science, and SPORTDiscus up to March 2015 to capture all relevant articles. A systematic approach was used to evaluate the 996 articles identified for initial review. Studies were included only if they investigated healthy individuals aged ≥6 years and tested at least one measure of static steady-state balance (e.g., center of pressure [CoP] displacement during one-legged stance), dynamic steady-state balance (e.g., gait speed), proactive balance (e.g., distance in the functional-reach-test), or reactive balance (e.g., CoP displacement during perturbed one-legged stance), and one measure of maximal strength (e.g., maximum voluntary contraction), explosive force (e.g., rate of force development), or muscle power (e.g., jump height). In total, 37 studies met the inclusionary criteria for review. The included studies were coded for the following criteria: age (i.e., children: 6-12 years, adolescents: 13-18 years, young adults: 19-44 years, middle-aged adults: 45-64 years, old adults: ≥65 years), sex (i.e., female, male), and test modality/outcome (i.e., test for the assessment of balance
KIm, Baek Joong; Yi, Chong Ku
In Korea, attempts have been made to develop high strength concrete for the safety and design life improvement of nuclear power plants. In this study, the cracking potentials of nuclear power plant-high strength concretes (NPP-HSCs) containing industrial by-products with W/B 0.34 and W/B 0.28, which are being reviewed for their application in the construction of containment structures, were evaluated through autogenous shrinkage, unrestrained drying shrinkage, and restrained drying shrinkage experiments. The cracking potentials of the NPP-HSCs with W/B 0.34 and W/B 0.28 were in the order of 0.34FA25 > 0.34FA25BFS25 > 0.34BFS50 > 0.34BFS65SF5 and 0.28FA25SF5 >> 0.28BFS65SF5 > 0.28BFS45SF5 > 0.28 FA20BFS25SF5, respectively. The cracking potentials of the seven mix proportions excluding 0.28FA25SF5 were lower than that of the existing nuclear power plant concrete; thus, the durability of a nuclear power plant against shrinkage cracking could be improved by applying the seven mix proportions with low cracking potentials
KIm, Baek Joong; Yi, Chong Ku [School of Civil, Environmental and Architectural Engineering, Korea University, Seoul (Korea, Republic of)
In Korea, attempts have been made to develop high strength concrete for the safety and design life improvement of nuclear power plants. In this study, the cracking potentials of nuclear power plant-high strength concretes (NPP-HSCs) containing industrial by-products with W/B 0.34 and W/B 0.28, which are being reviewed for their application in the construction of containment structures, were evaluated through autogenous shrinkage, unrestrained drying shrinkage, and restrained drying shrinkage experiments. The cracking potentials of the NPP-HSCs with W/B 0.34 and W/B 0.28 were in the order of 0.34FA25 > 0.34FA25BFS25 > 0.34BFS50 > 0.34BFS65SF5 and 0.28FA25SF5 >> 0.28BFS65SF5 > 0.28BFS45SF5 > 0.28 FA20BFS25SF5, respectively. The cracking potentials of the seven mix proportions excluding 0.28FA25SF5 were lower than that of the existing nuclear power plant concrete; thus, the durability of a nuclear power plant against shrinkage cracking could be improved by applying the seven mix proportions with low cracking potentials.
Bakke, M; Kirkeby, S; Jensen, B L
Histologic examination of muscle biopsies and functional examination comprising electromyography and force measurements in a 19-yr-old boy with muscular dystrophy showed different wasting patterns of mandibular elevator and depressor muscles. Pronounced histopathologic changes were present...... depressor strength corresponded more to reference values. This difference of muscular wasting might be caused by protective enzymes in the digastric muscle and/or functionally induced damage of the masseter. As affection from muscular dystrophy may vary greatly between the masticatory muscles, structural...... in the masseter muscle, whereas pathologic findings in the anterior digastric muscle were limited to increased number of cells in slightly enlarged interfiber connective tissue. The masticatory pattern was distorted, and strength of mandibular elevator muscles was less than one third of the norm, whereas...
Williams, Gavin; Banky, Megan; Olver, John
The main aim of this project was to determine the impact of plantarflexor spasticity on muscle performance for ambulant people with traumatic brain injury (TBI). A large metropolitan rehabilitation hospital. Seventy-two ambulant people with TBI who were attending physiotherapy for mobility limitations. Twenty-four participants returned for a 6-month follow-up reassessment. Cross-sectional cohort study. Self-selected walking speed, Tardieu scale, ankle plantarflexor strength, and ankle power generation (APG). Participants with ankle plantarflexor spasticity had significantly lower self-selected walking speed; however, there was no significant difference in ankle plantarflexor strength or APG. Participants with ankle plantarflexor spasticity were not restricted in the recovery of self-selected walking speed, ankle plantarflexor strength, or APG, indicating equivalent ability to improve their mobility over time despite the presence of spasticity. Following TBI, people with ankle plantarflexor spasticity have significantly greater mobility limitations than those without spasticity, yet retain the capacity for recovery of self-selected walking speed, ankle plantarflexor strength, and APG.
Jiménez Díaz, José Fernando
Full Text Available ResumenDurante la práctica de la actividad física hay una gran incidencia de lesiones musculares, si bien se han llevado a cabo pocos estudios clínicos sobre el tratamiento y la resolución de las mismas. Desde el punto de vista etiopatogénico, hay que señalar que la incidencia de lesión es mayor en aquellos músculos poliarticulares en condiciones de acumulación de fatiga y con condiciones ambientales desfavorables. La clasificación de las lesiones musculares permite distinguir entre aquellas que no afectan a la fascia produciéndose un sangrado dentro del mismo (intramuscular o bien si la fascia también se rompe, el sangrado se sitúa entre los diferentes músculos (intermuscular. El tratamiento de estas lesiones se realizará combinando reposo, compresión, aplicación de frío y elevación del área lesionada así como el desarrollo de un adecuado programa de readaptación funcional que permita al jugador incorporarse lo antes posible a la dinámica del equipo. En la actualidad se está llevando a cabo opciones terapéuticas con factores de crecimiento, terapia génica y células madre, si bien todavía no están lo suficientemente desarrolladas.AbstractDuring the practice of the physical activity there is a great effect of muscular injuries, though few clinical studies have been carried out on the treatment and the resolution of the same ones. Inside the reasons it is necessary to indicate that the effect of injury is major in those muscles you will polyarticulate in situation of fatigue and with environmental unfavorable conditions.The classification of the muscular injuries allows to distinguish between those that do not affect the fascia producing the bled intramuscular or if the fascia also breaks, the bled one places between the different muscles (intermuscular.The treatment will be realized combining rest, compression, application of cold and elevation of these injuries as well as the development of a program of functional
Trombetti, A; Reid, K F; Hars, M; Herrmann, F R; Pasha, E; Phillips, E M; Fielding, R A
This 3-year longitudinal study among older adults showed that declining muscle mass, strength, power, and physical performance are independent contributing factors to increased fear of falling, while declines of muscle mass and physical performance contribute to deterioration of quality of life. Our findings reinforce the importance of preserving muscle health with advancing age. The age-associated loss of skeletal muscle quantity and function are critical determinants of independent physical functioning in later life. Longitudinal studies investigating how decrements in muscle components of sarcopenia impact fear of falling (FoF) and quality of life (QoL) in older adults are lacking. Twenty-six healthy older subjects (age, 74.1 ± 3.7; Short Physical Performance Battery (SPPB) score ≥10) and 22 mobility-limited older subjects (age, 77.2 ± 4.4; SPPB score ≤9) underwent evaluations of lower extremity muscle size and composition by computed tomography, strength and power, and physical performance at baseline and after 3-year follow-up. The Falls Efficacy Scale (FES) and Short Form-36 questionnaire (SF-36) were also administered at both timepoints to assess FoF and QoL, respectively. At 3-year follow-up, muscle cross-sectional area (CSA) (p < 0.013) and power decreased (p < 0.001), while intermuscular fat infiltration increased (p < 0.001). These decrements were accompanied with a longer time to complete 400 m by 22 ± 46 s (p < 0.002). Using linear mixed-effects regression models, declines of muscle CSA, strength and power, and SPPB score were associated with increased FES score (p < 0.05 for each model). Reduced physical component summary score of SF-36 over follow-up was independently associated with decreased SPPB score (p < 0.020), muscle CSA (p < 0.046), and increased 400 m walk time (p < 0.003). In older adults with and without mobility limitations, declining muscle mass, strength, power, and physical
Miltner, O; Siebert, C; Tschaepe, R; Maus, U; Kieffer, O
The aim of this study was to analyse the efficiency of muscular activity in the trunk stabilisation of professional volleyball players compared to a group of amateur hobby players. The results were compared amongst the groups as well as with a reference group consisting of asymptomatic individuals. The question to be answered was whether or not professional volleyball players possess a characteristic strength profile in their trunk musculature and if differences exist with regard to the individuals' competitive playing level. In this comparative study 12 professional volleyball players (German Bundesliga) and 18 non-professional volleyball players were analysed with regard to their isometric strength profile in all three planes. The reference group was provided by the Proxomed company, which had previously analysed healthy untrained individuals (n = 1045) of various age groups. A sports-specific profile for the musculature of volleyball players revealed a significant reduction in the flexion and rotation strength as well as a well-developed lateral flexion strength (highly significant when compared to the reference group). With reference to the level played, better strength values in flexion and lateral flexion were found among the professional athletes. Professional volleyball players present with a characteristic trunk musculature strength profile. A detailed analysis of the muscle strength of the spine as part of a sports medicine work-up could prove helpful in preventing injuries and overuse problems in professional and hobby volleyball players.
Gabriela Palhares Campolina Diniz
Full Text Available OBJECTIVE: Evaluate muscle force and motor function in patients with Duchenne muscular dystrophy (DMD in a period of six months. METHOD: Twenty children and adolescents with diagnosis of DMD were evaluated trough: measurement of the strength of the flexors and extensors of the shoulder, elbow, wrist, knee and ankle through the Medical Research Council (MRC, and application of the Motor Function Measure (MFM. The patients were evaluated twice within a six-month interval. RESULTS: Loss of muscle strength was identified in the MRC score for upper proximal members (t=-2.17, p=0.04. In the MFM, it was noted significant loss in the dimension 1 (t=-3.06, p=0.006. Moderate and strong correlations were found between the scores for muscular strength and the MFM dimensions. CONCLUSION: The MFM scale was a useful instrument in the follow up of patients with DMD. Moreover, it is a more comprehensive scale to assess patients and very good for conducting trials to evaluate treatment.
Bennett, Jane G.; Murphy, Debra J.
Physical education teachers should incorporate the concept of muscular balance into their daily curricula and select activities that work the muscles as they are used in everyday activities. The article focuses on maintaining normal strength between the anterior and posterior trunk muscles, detailing appropriate exercises. (SM)
Full Text Available Stretching is a physical therapeutical way for maintaining the standard parameters of the body functions from a tender to anadvanced age. The most important parameter that is influenced by the different techniques of stretching, especially byhydrostretching, is flexibility. This article presents the technique and the effects of hydrostretching on human body (onmuscular balance, strength, muscular metabolism and circulation.
... Boost from Existing Medication Spotlight on Research Experimental Treatment for Duchenne Muscular Dystrophy Gets Boost from Existing Medication By Colleen Labbe, M.S. | March 1, 2013 A mouse hanging on a wire during a test of muscle strength. Mice with a mutant dystrophin gene, which ...
Morais, Jorge E; Silva, António J; Garrido, Nuno D; Marinho, Daniel A; Barbosa, Tiago M
The purpose of this study was to learn the interplay between dry-land strength and conditioning, and stroke biomechanics in young swimmers, during a 34-week training programme. Twenty-seven swimmers (overall: 13.33 ± 0.85 years old; 11 boys: 13.5 ± 0.75 years old; 16 girls: 13.2 ± 0.92 years old) competing at regional- and national-level competitions were evaluated. The swimmers were submitted to a specific in-water and dry-land strength training over 34 weeks (and evaluated at three time points: pre-, mid-, and post-test; M1, M2, and M3, respectively). The 100-m freestyle performance was chosen as the main outcome (i.e. dependent variable). The arm span (AS; anthropometrics), throwing velocity (TV; strength), stroke length (SL), and stroke frequency (SF; kinematics) were selected as independent variables. There was a performance enhancement over time (M1 vs. M3: 68.72 ± 5.57 s, 66.23 ± 5.23 s; Δ = -3.77%; 95% CI: -3.98;-3.56) and an overall improvement of the remaining variables. At M1 and M2, all links between variables presented significant effects (p biomechanics parameters (SL and SF) increased. The model predicted 89%, 88%, and 92% of the performance at M1, M2, and M3, respectively, with a reasonable adjustment (i.e. goodness-of-fit M1: χ 2 /df = 3.82; M2: χ 2 /df = 3.08; M3: χ 2 /df = 4.94). These findings show that strength and conditioning parameters have a direct effect on the stroke biomechanics, and the latter one on the swimming performance.
FAREED AHMED MEMON
Full Text Available This research study comprises of concrete cubes made with Ordinary Portland Cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25%, 50%, 75% and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10%, 25%, 50%, and 75% of cement with fly ash. The cubes were 6\\" x 6\\" in cross-section, and the mix design was aimed for 5000 psi. After proper curing of all 81 cubes, they were tested at 3, 7 and 28 days curing age. The cubes were tested in Forney Universal Testing Machine. By analyzing the test results of all the concrete cubes, the following main findings have been drawn. The compressive strength of concrete cubes made by replacing 100 % fine aggregate by fly ash was higher than the concrete cubes made with Ordinary Portland Cement at all 3, 7 and 28 days curing ages. On the other hand, the compressive strength of concrete cubes made by replacing 10 % and 25 % cement by fly ash was slightly lower than the concrete cubes made with Ordinary Portland Cement at all curing ages, whereas, the compressive strength of concrete cubes made by replacing 50 % and 75 % of cement by fly ash were quite lower than the concrete cubes made with Ordinary Portland Cement at all curing ages.
Løkken, Nicoline; Hedermann, Gitte; Thomsen, Carsten; Vissing, John
We investigated whether a linear relationship between muscle strength and cross-sectional area (CSA) is preserved in calf muscles of patients with Becker muscular dystrophy (BMD, n = 14) and limb-girdle type 2I muscular dystrophy (LGMD2I, n = 11), before and after correcting for muscle fat infiltration. The Dixon magnetic resonance imaging technique was used to quantify fat and calculate a fat-free contractile CSA. Strength was assessed by dynamometry. Muscle strength/CSA relationships were significantly lower in patients versus controls. The strength/contractile-CSA relationship was still severely lowered in BMD, but was almost normalized in LGMD2I. Our findings suggest close to intact contractile properties in LGMD2I, which are severely disrupted in BMD. Ann Neurol 2016;80:466-471. © 2016 American Neurological Association.
Yoon, Dong Hyun; Kang, Dongheon; Kim, Hee-Jae; Kim, Jin-Soo; Song, Han Sol; Song, Wook
The effectiveness of resistance training in improving cognitive function in older adults is well demonstrated. In particular, unconventional high-speed resistance training can improve muscle power development. In the present study, the effectiveness of 12 weeks of elastic band-based high-speed power training (HSPT) was examined. Participants were randomly assigned into a HSPT group (n = 14, age 75.0 ± 0.9 years), a low-speed strength training (LSST) group (n = 9, age 76.0 ± 1.3 years) and a control group (CON; n = 7, age 78.0 ± 1.0 years). A 1-h exercise program was provided twice a week for 12 weeks for the HSPT and LSST groups, and balance and tone exercises were carried out by the CON group. Significant increases in levels of cognitive function, physical function, and muscle strength were observed in both the HSPT and LSST groups. In cognitive function, significant improvements in the Mini-Mental State Examination and Montreal Cognitive Assessment were seen in both the HSPT and LSST groups compared with the CON group. In physical functions, Short Physical Performance Battery scores were increased significantly in the HSPT and LSST groups compared with the CON group. In the 12 weeks of elastic band-based training, the HSPT group showed greater improvements in older women with mild cognitive impairment than the LSST group, although both regimens were effective in improving cognitive function, physical function and muscle strength. We conclude that elastic band-based HSPT, as compared with LSST, is more efficient in helping older women with mild cognitive impairment to improve cognitive function, physical performance and muscle strength. Geriatr Gerontol Int 2017; 17: 765-772. © 2016 Japan Geriatrics Society.
Kabiri, Laura S; Mitchell, Katy; Brewer, Wayne; Ortiz, Alexis
The growth and unregulated structure of homeschooling creates an unknown population in regard to muscular and cardiorespiratory fitness. The purpose of this research was to compare muscular and cardiorespiratory fitness between elementary school aged homeschool and public school children. Homeschool children ages 8-11 years old (n = 75) completed the curl-up, 90° push-up, and Progressive Aerobic Capacity Endurance Run (PACER) portions of the FitnessGram to assess abdominal and upper body strength and endurance as well as cardiorespiratory fitness. Comparisons to public school children (n = 75) were made using t tests and chi-square tests. Homeschool children showed significantly lower abdominal (t(148) = -11.441, p fitness by total PACER laps (t(108) = 0.879, p = .381) or estimated VO 2max (t(70) = 1.187, p = .239; χ 2 (1) = 1.444, p = .486). Homeschool children showed significantly lower levels of both abdominal and upper body muscular fitness compared with their age and gender matched public school peers but no difference in cardiorespiratory fitness.
Myers, Kenneth A; Ramage, Barbara; Khan, Aneal; Mah, Jean K
Duchenne muscular dystrophy is an X-linked recessive muscular dystrophy. Clinical management primarily involves rehabilitation strategies aimed at preserving functional mobility as long as possible. Side-alternating vibration therapy is a rehabilitation intervention that has shown promise in a number of different neuromuscular disorders, and has the potential to preserve strength, functional mobility, and bone mass. There has been little research regarding the tolerance to side-alternating vibration therapy in muscle diseases such as Duchenne muscular dystrophy. Four patients were recruited for a pilot study assessing the safety and tolerance of side-alternating vibration therapy in individuals with Duchenne muscular dystrophy. All patients participated in a 4-week training period involving side-alternating vibration therapy sessions three times per week. Serum creatine kinase was measured, and adverse effects reviewed at each session with functional mobility assessed before and after the training period. All patients tolerated the training protocol well, and there were no major changes in functional mobility. One patient had a transient increase in creatine kinase during the study; however, levels of this enzyme were stable overall when comparing the pretraining and posttraining values. Some patients reported subjective improvement during the training period. Side-alternating vibration therapy is well tolerated in children with Duchenne muscular dystrophy and may have potential to improve or maintain functional mobility and strength in these patients. Copyright © 2014 Elsevier Inc. All rights reserved.
Mills, Robin W; Uhl, Alexander; Blackwell, Gordon B; Jandt, Klaus D
The clinical performance of light polymerized dental composites is greatly influenced by the quality of the light curing unit (LCU) used. Commonly used halogen LCUs have some specific drawbacks such as decreasing light output with time. This may result in a low degree of monomer conversion of the composites with negative clinical implications. Previous studies have shown that blue light emitting diode (LED) LCUs have the potential to polymerize dental composites without having the drawbacks of halogen LCUs. Since these studies were carried out LED technology has advanced significantly and commercial LED LCUs are now becoming available. This study investigates the Barcol hardness as a function of depth, and the compressive strength of dental composites that had been polymerized for 40 or 20s with two high power LED LCU prototypes, a commercial LED LCU, and a commercial halogen LCU. In addition the radiometric properties of the LCUs were characterized. The two high power prototype LED LCUs and the halogen LCU showed a satisfactory and similar hardness-depth performance whereas the hardness of the materials polymerized with the commercial LED LCU rapidly decreased with sample depth and reduced polymerization time (20 s). There were statistically significant differences in the overall compressive strengths of composites polymerized with different LCUs at the 95% significance level (p = 0.0016) with the two high power LED LCU prototypes and the halogen LCU forming a statistically homogenous group. In conclusion, LED LCU polymerization technology can reach the performance level of halogen LCUs. One of the first commercial LED LCUs however lacked the power reserves of the high power LED LCU prototypes.
Lopes, Thiago Jambo Alves; Simic, Milena; Alves, Daniel de Souza; Bunn, Priscila Dos Santos; Rodrigues, Allan Inoue; Terra, Bruno de Souza; Lima, Maicom da Silva; Ribeiro, Fabrício Miranda; Vilão, Patrick; Pappas, Evangelos
The objectives were to provide normative data on commonly used physical performance tests that may be associated with musculoskeletal injuries in Navy cadets, and assess for sex and limb dominance differences. A large cohort of Navy cadets were assessed for physical performance tests of flexibility (ankle dorsiflexion range of motion and sit and reach), isometric hip strength, lower limb power (single leg hop), and trunk endurance (plank and side plank tests). Besides providing normative data tables, sex and limb dominance differences were assessed by a two-way mixed ANOVA. A total of 545 Brazilian Navy cadets (394 males) representing 79% of the cadets in the Academy participated. Normative reference values were reported as mean±SD, 95%CI and percentiles. For tests of muscle strength, power and endurance, males performed better than females (p<0.001). For flexibility tests, females achieved greater distances than males for the sit and reach test (p<0.001), but no difference for ankle dorsiflexion (p=0.51). Overall, there were no clinically relevant differences between limbs. In conclusion, normative data for commonly used physical performance tests were provided. Although no clinically relevant side-to-side differences were found, males presented higher values for lower limb strength and power, as well as trunk endurance than females, while females demonstrated increased flexibility. Valuable normative data are provided to professionals who work with young, active populations from the injury prevention or rehabilitation perspective; as the current study may help professionals to identify athletes or cadets whose performance is outside the normative values and may be at risk for injury.
Fields, Karl B; Rigby, Michael D
Calf pain is a common complaint among runners of all ages but is most frequent in masters athletes. This article focuses on injuries to the triceps surae or true 'calf muscles.' The most common calf injury is a tear of the medial gastrocnemius muscle (Tennis Leg) but other structures including the lateral gastrocnemius, plantaris and soleus also may be the cause of muscular pain. This article looks at the presentation, evaluation, and treatment of these injuries. We also highlight some examples of musculoskeletal ultrasound which is a valuable tool for rapid diagnosis of the cause and extent of injury.
Jason L. Buckner
Full Text Available Duchenne muscular dystrophy (DMD is an X-linked recessive disorder characterized by progressive muscle weakness, with eventual loss of ambulation and premature death. The approved therapy with corticosteroids improves muscle strength, prolongs ambulation, and maintains pulmonary function. However, the osteoporotic impact of chronic corticosteroid use further impairs the underlying reduced bone mass seen in DMD, leading to increased fragility fractures of long bones and vertebrae. These serious sequelae adversely affect quality of life and can impact survival. The current clinical issues relating to bone health and bone health screening methods in DMD are presented in this review. Diagnostic studies, including biochemical markers of bone turnover and bone mineral density by dual energy X-ray absorptiometry (DXA, as well as spinal imaging using densitometric lateral spinal imaging, and treatment to optimize bone health in patients with DMD are discussed. Treatment with bisphosphonates offers a method to increase bone mass in these children; oral and intravenous bisphosphonates have been used successfully although treatment is typically reserved for children with fractures and/or bone pain with low bone mass by DXA.
Lee, Gun Cheol; Han, Min Cheol; Baek, Dae Hyun; Koh, Kyung Taek
The objective of this study was to experimentally investigate the effect of heat curing methods on the temperature history and strength development of slab concrete exposed to -10 degrees Celsius. The goal was to determine proper heat curing methods for the protection of nuclear power plant structures against early-age frost damage under adverse (cold) conditions. Two types of methods were studied: heat insulation alone and in combination with a heating cable. For heat curing with heat insulation alone, either sawdust or a double layer bubble sheet (2-BS) was applied. For curing with a combination of heat insulation and a heating cable, an embedded heating cable was used with either a sawdust cover, a 2-BS cover, or a quadruple layer bubble sheet (4-BS) cover. Seven different slab specimens with dimensions of 1200, 600, 200 mm and a design strength of 27 MPa were fabricated and cured at -10 degrees Celsius for 7 d. The application of sawdust and 2-BS allowed the concrete temperature to fall below 0 degrees Celsius within 40 h after exposure to -10 degrees Celsius, and then, the temperature dropped to -10 degrees Celsius and remained there for 7 d owing to insufficient thermal resistance. However, the combination of a heating cable plus sawdust or 2-BS maintained the concrete temperature around 5 degrees Celsius for 7 d. Moreover, the combination of the heating cable and 4-BS maintained the concrete temperature around 10 degrees Celsius for 7 d. This was due to the continuous heat supply from the heating cable and the prevention of heat loss by the 4-BS. For maturity development, which is an index of early-age frost damage, the application of heat insulation materials alone did not allow the concrete to meet the minimum maturity required to protect against early-age frost damage after 7 d, owing to poor thermal resistance. However, the combination of the heating cable and the heat insulating materials allowed the concrete to attain the minimum maturity level after
Cherif, M; Chtourou, H; Souissi, N; Aouidet, A; Chamari, K
This study was designed to assess the effect of strength and power training on throwing velocity and muscle strength in handball players according to their playing positions. Twenty-two male handball players were assigned to either an experimental group (n=11) or a control group (n=11) (age: 22.1 ± 3.0 years). They were asked to complete (i) the ball throwing velocity test and (ii) the one-repetition maximum (1-RM) tests for the half-back squat, the pull-over, the bench press, the developed neck, and the print exercises before and after 12 weeks of maximal power training. The training was designed to improve strength and power with an intensity of 85-95% of the 1RM. In addition to their usual routine handball training sessions, participants performed two sessions per week. During each session, they performed 3-5 sets of 3-8 repetitions with 3 min of rest in between. Then, they performed specific shots (i.e., 12 to 40). Ball-throwing velocity (p<0.001) was higher after the training period in rear line players (RL). The training programme resulted in an improvement of 1RM bench press (p<0.001), 1RM developed neck (p<0.001) and 1RM print (p<0.001) in both front line (FL) and RL. The control group showed a significant improvement only in ball-throwing velocity (p<0.01) and 1RM bench press (p<0.01) in RL. A significantly greater improvement was found in ball-throwing velocity (p<0.001), 1RM bench press (p<0.001), and 1RM half-back squat exercises in players of the central axis (CA) compared to the lateral axis (LA) (p<0.01). The power training programme induced significantly greater increases in ball-throwing velocity and muscle strength in FL than RL and in CA than LA axis players.
Kalsen, Anders; Hostrup, Morten; Backer, Vibeke
The aim was to investigate the effect of the long-acting β2-adrenergic agonist formoterol on muscle strength and power output, muscle metabolism and phosphorylation of CaMKII Thr(287) and FXYD1 during maximal sprinting. In a double-blind crossover study, thirteen males (VO2max: 45.0±0.2 (mean±SE) m......L min(-1) kg(-1)) performed a 30-s cycle ergometer sprint after inhalation of either 54 µg formoterol (FOR) or placebo (PLA). Before and after the sprint, muscle biopsies were collected from vastus lateralis and maximal voluntary contraction (MVC) and contractile properties of quadriceps were measured...
José Antonio Levy
Full Text Available Com base em trabalhos anteriores, 13 casos de distrofia muscular progressiva foram tratados com lactato de sódio 1/6 molar associado a ATP e complexo B. O exame da força muscular, realizado antes e após o tratamento — salvo em dois casos nos quais ocorreram melhoras muito discretas — não mostrou qualquer efeito favorável da medicação. Os autores sugerem a verificação de possíveis alterações enzimáticas provocadas pelo lactato de sódio, o que serviria para melhor avaliação do efeito terapêutico.Thirteen cases of progressive muscular dystrophy were treated with 1/6 M. sodium lactate plus ATP and B complex. Examinations of muscle strength, before and after the treatment, did not show any favourable effects, except in two of the cases which showed slight improvement. The authors suggest that possible enzimatic alterations caused by the sodium lactate be checked up on, since this checking could be employed in the evaluation of the therapeutic effects.
Khirani, Sonia; Ramirez, Adriana; Aubertin, Guillaume; Boulé, Michèle; Chemouny, Chrystelle; Forin, Véronique; Fauroux, Brigitte
Duchenne muscular dystrophy (DMD) causes progressive respiratory muscle weakness. The aim of the study was to analyze the trend of a large number of respiratory parameters to gain further information on the course of the disease. Retrospective study. 48 boys with DMD, age range between 6 and 19 year old, who were followed in our multidisciplinary neuromuscular clinic between 2001 and 2011. Lung function, blood gases, respiratory mechanics, and muscle strength were measured during routine follow-up over a 10-year period. Only data from patients with at least two measurements were retained. The data of 28 patients were considered for analysis. Four parameters showed an important decline with age. Gastric pressure during cough (Pgas cough) was below normal in all patients with a mean decline of 5.7 ± 3.8 cmH2 O/year. Sniff nasal inspiratory pressure (SNIP) tended to increase first followed by a rapid decline (mean decrease 4.8 ± 4.9 cmH2 O; 5.2 ± 4.4% predicted/year). Absolute forced vital capacity (FVC) values peaked around the age of 13-14 years and remained mainly over 1 L but predicted values showed a mean 4.1 ± 4.4% decline/year. Diaphragmatic tension-time index (TTdi) increased above normal values after the age of 14 years with a mean increase of 0.04 ± 0.04 point/year. This study confirms the previous findings that FVC and SNIP are among the most important parameters to monitor the evolution of DMD. Expiratory muscle strength, assessed by Pgas cough, and the endurance index, TTdi, which are reported for the first time in a large cohort, appeared to be informative too, even though measured through an invasive method. © 2013 Wiley Periodicals, Inc.
Elisângela Valevein Rodrigues
Full Text Available AbstractIntroduction Physical exercise is indicated to reduce the incidence of musculoskeletal symptoms in teachers.Objective To evaluate the effects of muscular endurance training on muscle strength and musculoskeletal symptoms related to the lower limbs of public elementary school teachers.Materials and methods Thirty-one female teachers were divided into two groups: control (CG, n = 15 and muscular endurance training (TG, n = 16. The training consisted of two sets of 15 repetitions of exercises for quadriceps and hamstring muscle groups, twice a week, for 7 weeks, which were conducted with 50% of 10 repetition maximum(10RM (first to fourth week and 60% of 10 RM (fifth to seventh week. Musculoskeletal symptoms (Nordic Musculoskeletal Questionnaire, isometric peak torque (Load cell and muscle strength (10RM were assessed before and after intervention. ANOVA for repeated measures and Tukey post hoc were used to analyse strength and peak torque of quadriceps and hamstrings and Chi-square goodness-of-fit test were used to analyse the frequency of occurrence of osteomuscular symptoms.Results The highest incidence of symptoms was found in the lumbar region in both groups. Training caused increased muscle strength of the quadriceps and hamstrings, but there were no significant differences in either the peak torque in the quadriceps and hamstrings or in the reduction of musculoskeletal symptoms.Conclusion The exercise program performed in this study increased the dynamic strength in the TG in relation to the CG, but did not alter the incidence of symptoms in the lumbar region and lower limbs in neither of the groups. Thus, results suggest that the duration of intervention may not have been enough to increase peak torque and decrease musculoskeletal symptoms.
Park, Junsu [Department of Nano-Manufacturing Technology, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103 (Korea, Republic of); Sin, Young-Gwan [Department of Nano-Mechatronics, Korea University of Science and Technology (UST), 217 Gajeong-Ro, Yuseong-Gu, Daejeon 34113 (Korea, Republic of); Kim, Jae-Hyun [Department of Nano-Mechanics, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103 (Korea, Republic of); Kim, Jaegu, E-mail: email@example.com [Department of Nano-Manufacturing Technology, Korea Institute of Machinery and Materials, 156 Gajeongbuk-Ro, Yuseong-Gu, Daejeon 34103 (Korea, Republic of)
Highlights: • Fundamental relationship between laser irradiation and adhesion strength, between gallium-nitride light emitted diode and sapphire substrate, is proposed during selective laser lift-off. • Two competing mechanisms affect adhesion at the irradiated interface between the GaN LED and sapphire substrate. • Ga precipitation caused by thermal decomposition and roughened interface caused by thermal damage lead to the considerable difference of adhesion strength at the interface. - Abstract: Selective laser lift-off (SLLO) is an innovative technology used to manufacture and repair micro-light-emitting diode (LED) displays. In SLLO, laser is irradiated to selectively separate micro-LED devices from a transparent sapphire substrate. The light source used is an ultraviolet (UV) laser with a wavelength of 266 nm, pulse duration of 20 ns, and repetition rate of 30 kHz. Controlled adhesion between a LED and the substrate is key for a SLLO process with high yield and reliability. This study examined the fundamental relationship between adhesion and laser irradiation. Two competing mechanisms affect adhesion at the irradiated interface between the GaN LED and sapphire substrate: Ga precipitation caused by the thermal decomposition of GaN and roughened interface caused by thermal damage on the sapphire. The competition between these two mechanisms leads to a non-trivial SLLO condition that needs optimization. This study helps understand the SLLO process, and accelerate the development of a process for manufacturing micro-LED displays via SLLO for future applications.
Thakker, P B; Sharma, A
A 15 year old boy who presented with passing painless dark urine was found to have myoglobinuria. His creatine phosphokinase was raised, and a muscle biopsy specimen showed non-specific dystrophic changes. Subsequent DNA analysis led to the diagnosis of Becker muscular dystrophy. Myoglobinuria may be a presenting symptom of Becker muscular dystrophy.
Dreesen, JCFM; Bras, M; de Die-Smulders, C; Dumoulin, JCM; Cobben, JM; Evers, JLH; Smeets, HJM; Geraedts, JPM
After Duchenne muscular dystrophy, spinal muscular atrophy (SMA) is the most common severe neuromuscular disease in childhood. Since 1995, homozygous deletions in exon 7 of the survival motor neuron (SMN) gene have been described in >90-95% of SMA patients. However, the presence of a highly
A survey of roentgenological findings in muscular alterations of extremities based on the author's experiences and on the literature is presented. Following a description of the normal roentgen anatomy, the alterations in different diseases of interstitial lipomatosis are demonstrated. By roentgenological examinations differt muscular lesions of the extremities can be differentiated and the clinical follow-up verified. (orig.) [de
Roig, Marc; Eng, Janice J.; MacIntyre, Donna L.
associations of the SCPT with muscle strength (force-generating capacity) and functional performance. DESIGN: The study was a cross-sectional investigation. METHODS: Twenty-one people with COPD and a predicted mean (SD) percentage of forced expiratory volume in 1 second of 47.2 (12.9) and 21 people who were......: The observational design of the study and the use of a relatively small convenience sample limit the generalizability of the findings. CONCLUSIONS: The SCPT is a simple and safe test associated with measures of functional performance in people with COPD. People with COPD show deficits on the SCPT. However, the SCPT......BACKGROUND: The Stair Climb Power Test (SCPT) is a functional test associated with leg muscle power in older people. OBJECTIVE: The purposes of this study were to compare the results of the SCPT in people with chronic obstructive pulmonary disease (COPD) and people who were healthy and to explore...
The properties of a constructional material determining life are strength, plasticity, and crack resistance. Loss of properties occurs as the result of corrosion, temperature action, actual and residual stresses, and neutron and gamma-radiation. Corrosion leads to a decrease in thickness, loss of density, changes in the composition and structure of the surface layers, and a reduction in strength, plasticity, and crack resistance of constructional materials. The influence of temperature on the loss of properties of materials is revealed as possible phase and structural transformations of the metal and the surface layers and a reduction in the stress-rupture, plastic, and thermal-fatigue properties. The actual and residual stresses not only strengthen the influence of corrosive media but also directly determine the stress-rupture strength and cyclic life. The influence of neutron and gamma-radiation is based o the change in composition of the corrosive medium (radiolysis), radiation embrittlement of the material, and the change in properties of the surface and oxide layers. The authors discuss the concepts and design of automated monitoring systems for determining the fitness of the components of on atomic power plant
Full Text Available Study aim: The aim of the present study was to determine a strength profile which characterizes young male athletes from different sports and to use the method of allometry to synthetically evaluate the muscular strength with respect to body mass.
Witting, Nanna; Duno, M; Vissing, J
Becker muscular dystrophy features progressive proximal weakness, wasting and often focal hypertrophy. We present a patient with pain and cramps from adolescence. Widespread muscle hypertrophy, preserved muscle strength and a 10-20-fold raised CPK were noted. Muscle biopsy was dystrophic......, and Western blot showed a 95% reduction of dystrophin levels. Genetic analyses revealed a non-sense mutation in exon 2 of the dystrophin gene. This mutation is predicted to result in a Duchenne phenotype, but resulted in a mild Becker muscular dystrophy with widespread muscle hypertrophy. We suggest...
Hong, Y; Chan, K; Wang, Y
A study on the data of the physique investigated in teenagers was carried out between Hong Kong and inland cities to compare their cardiopulmonary endurance and muscular fitness. Results revealed that cardiopulmonary endurance in school teenagers of both sex at different ages in inland cities was better than that in Hong Kong. Muscular strength and endurance of sports performance of teenagers, except for standing long jump, in Hong Kong were weaker than that in inland cities. It suggests that attention should be paid to the involvement of teenagers in physical education with the increase of people's living standard.
Rogers, Benjamin H.; Brown, Justin C.; Gater, David R.; Schmitz, Kathryn H.
Objective One-repetition maximum (1-RM) bench press strength is considered the gold standard to quantify upper-body muscular strength. Isometric handgrip strength is frequently used as a surrogate for 1-RM bench press strength among breast cancer (BrCa) survivors. The relationship between 1-RM bench press strength and isometric handgrip strength, however, has not been characterized among BrCa survivors. Design Cross-sectional study. Setting Laboratory. Participants Community-dwelling BrCa survivors. Interventions Not applicable. Main Outcome Measure 1-RM bench press strength was measured with a barbell and exercise bench. Isometric handgrip strength was measured using an isometric dynamometer with three maximal contractions of left and right hands. All measures were conducted by staff with training in clinical exercise testing. Results Among 295 BrCa survivors, 1-RM bench press strength was 18.2±6.1 kg (range: 2.2-43.0) and isometric handgrip strength was 23.5±5.8 kg (range: 9.0-43.0). The strongest correlate of 1-RM bench press strength was the average isometric handgrip strength of both hands (r=0.399; Pisometric handgrip strength of both hands overestimated 1-RM bench press strength by 4.7 kg (95% limits of agreement: −8.2 to 17.6). In a multivariable linear regression model, the average isometric handgrip strength of both hands (β=0.31; Pstrength (R2=0.23). Conclusions Isometric handgrip strength is a poor surrogate for 1-RM bench press strength among BrCa survivors. 1-RM bench press and isometric handgrip strength quantify distinct components of muscular strength. PMID:27543047
Khun, N W; Liu, E
Nitrogen doped diamond-like carbon (DLC:N) thin films were deposited on highly conductive p-Si substrates using a DC magnetron sputtering deposition system. The DLC:N films were characterized using X-ray photoelectron spectroscopy (XPS), micro-Raman spectroscopy, atomic force microscopy (AFM), contact angle measurement and micro-scratch test. The XPS and Raman results indicated that the sputtering power significantly influenced the properties of the films in terms of bonding configuration in the films. The corrosion performance of the DLC:N films was investigated in a 0.6 M NaCl solution by means of potentiodynamic polarization testing. It was found that the corrosion performance of the films could be enhanced by higher sputtering powers.
Andersen, Grete; Prahm, Kira P; Dahlqvist, Julia R
) and women (n = 20) with FSHD (age 19-65 years) to 2 training groups-training with protein supplement (n = 18) and training with placebo supplement (n = 13)-and a nonintervention control group (n = 10). We assessed fitness, walking speed, muscle strength, questionnaires, and daily activity levels before......%-15%], 18% [CI 10%-26%], 7% [CI 4%-11%], respectively, p physical capacity and health (Short Form-36) also improved. Muscle strength and daily activity levels did not change with training. Protein-carbohydrate supplementation did not result in further......OBJECTIVE: To investigate the effect of regular aerobic training and postexercise protein-carbohydrate supplementation in patients with facioscapulohumeral muscular dystrophy (FSHD). METHODS: In this randomized, double-blind, placebo-controlled parallel study, we randomized untrained men (n = 21...
Full Text Available Background: It is theorized that the development of the ability to stabilize the trunk may improve the performance of a judoka because it improves body balance control and optimizes force transmission from the lower extremities to the upper limbs. However, there is a lack of scientific evidence to establish a clear relationship between trunk stability and performance in judo.Aim: The purpose of this study was to determine whether the quantification of trunk stability and muscular strength and endurance allowed differentiation between national level (n = 7 and international level judoka (n = 6. In addition, the relationship between trunk stability and muscular strength and endurance of the muscles involved in trunk stability control was analyzed.Method: To assess trunk stability, trunk responses to sudden loads applied by a pneumatic mechanism were analyzed, as well as trunk postural control through an unstable sitting paradigm. Muscular strength and endurance were assessed via a flexion and extension trunk test using an isokinetic dynamometer.Results/Conclusions: International level judokas showed lower CoP displacement in the most complex task in unstable seat (7.00 ± 1.19 vs 8.93 ± 1.45 mm, T = .025 and higher absolute and relative peak torque in extensor muscles (7.05 ± 0.87 vs 5.74 ± 0.72 Nm, T = .013 than national level judoka. According to these results, core stability and trunk muscular condition are important qualities in the physical training of elite judoka. Correlational analysis found no relation between the analyzed variables, thus muscular strength and endurance appear to have a non-significant effect on performance in the trunk stability tests.
Huckabee, M.L.; Buljan, S.T.; Neil, J.T.
A powder mixture and a green body for producing a silicon nitride-based article of improved fracture toughness and strength are disclosed. The powder mixture includes (a) a bimodal silicon nitride powder blend consisting essentially of about 10-30% by weight of a first silicon nitride powder of an average particle size of about 0.2 [mu]m and a surface area of about 8-12m[sup 2]g, and about 70-90% by weight of a second silicon nitride powder of an average particle size of about 0.4-0.6 [mu]m and a surface area of about 2-4 m[sup 2]/g, (b) about 10-50 percent by volume, based on the volume of the densified article, of refractory whiskers or fibers having an aspect ratio of about 3-150 and having an equivalent diameter selected to produce in the densified article an equivalent diameter ratio of the whiskers or fibers to grains of silicon nitride of greater than 1.0, and (c) an effective amount of a suitable oxide densification aid. The green body is formed from the powder mixture, an effective amount of a suitable oxide densification aid, and an effective amount of a suitable organic binder. No Drawings
Zeidan, Leonardo C; Esteves, Camila M; Oliveira, Juliana A; Brugnera, Aldo; Cassoni, Alessandra; Rodrigues, José Augusto
The aim of this study was to evaluate the effect of different output powers of Er,Cr:YSGG laser and the association with tribochemical silica coating on the bond strength between zirconia ceramic and two resin cements. One hundred ninety-two zirconia ceramic bars (IPS e-max ZirCAD Ivoclar Vivadent-) were sectioned (6 × 6 × 4 mm), sintered, and randomly divided into 12 groups for each cement system according to the surface treatment (n = 8): C-without treatment (control); R-tribochemical coating + resin cement (control); 2L-laser (2.0 W) + resin cement; 2LR-laser (2.0 W) + tribochemical coating + resin cement; R2L-tribochemical coating + laser (2.0 W) + resin cement; 2.5L-laser (2.5 W) + resin cement; 2.5LR-laser (2.5 W) + tribochemical coating + resin cement; R2.5L-tribochemical coating + laser (2.5 W) + resin cement; 3L-laser (3.0 W) + resin cement; 3LR-laser (3.0 W) + tribochemical coating + resin cement, R3L-tribochemical coating + laser (3.0 W) + resin cement; and RPHO-tribochemical + resin cement + photoactivation (control). After the surface treatment, the respective primers were applied, and resin cements, Multilink N, Ivoclar Vivadent (M), and Panavia F 2.0, Kuraray Medical Inc. (P), were inserted into Tygon molds which were bonded to the zirconia bars. Each specimen received two cements bars. After 24 h of storage in a relative humidity (100%) at 37 °C, they were evaluated by the microshear test speed of 1 mm/min. The microshear values were analyzed by one-way ANOVA and Tukey's test (α = 0.05). ANOVA showed statistically significant differences among the evaluated groups. The highest bond strength was observed in RPHO, which statistically differed from all groups. The lowest bond strength was observed in M2.5L (Multilink N) and in P3LR (Panavia F 2.0). It can be concluded that the lowest power output tested was suitable and showed bond strength values similar to tribochemical silica deposition. The light curing is important to
Travis A. Ryan
Full Text Available The Drive for Muscularity Attitudes Questionnaire (DMAQ was developed to measure men’s desire to attain an idealized muscular body. To date, the cross-cultural suitability of this measure has received limited attention. The current study addressed this omission by testing the psychometric properties of the DMAQ using an online sample of Irish men (N = 327. Confirmatory factor analysis revealed that a unidimensional model adequately matched observed data (i.e., fit indices suggested acceptable model fit. Analyses also showed that the DMAQ yielded reliable and construct valid scores, suggesting that the scale holds promise as an indicant of the drive for muscularity among Irish men. Strengths and limitations associated with this study are discussed, such as advantages and disadvantages of Internet research. Directions for future research are given, including the need for more psychometric work.
Lacroix, André; Kressig, Reto W; Muehlbauer, Thomas; Gschwind, Yves J; Pfenninger, Barbara; Bruegger, Othmar; Granacher, Urs
Losses in lower extremity muscle strength/power, muscle mass and deficits in static and particularly dynamic balance due to aging are associated with impaired functional performance and an increased fall risk. It has been shown that the combination of balance and strength training (BST) mitigates these age-related deficits. However, it is unresolved whether supervised versus unsupervised BST is equally effective in improving muscle power and balance in older adults. This study examined the impact of a 12-week BST program followed by 12 weeks of detraining on measures of balance and muscle power in healthy older adults enrolled in supervised (SUP) or unsupervised (UNSUP) training. Sixty-six older adults (men: 25, women: 41; age 73 ± 4 years) were randomly assigned to a SUP group (2/week supervised training, 1/week unsupervised training; n = 22), an UNSUP group (3/week unsupervised training; n = 22) or a passive control group (CON; n = 22). Static (i.e., Romberg Test) and dynamic (i.e., 10-meter walk test) steady-state, proactive (i.e., Timed Up and Go Test, Functional Reach Test), and reactive balance (e.g., Push and Release Test), as well as lower extremity muscle power (i.e., Chair Stand Test; Stair Ascent and Descent Test) were tested before and after the active training phase as well as after detraining. Adherence rates to training were 92% for SUP and 97% for UNSUP. BST resulted in significant group × time interactions. Post hoc analyses showed, among others, significant training-related improvements for the Romberg Test, stride velocity, Timed Up and Go Test, and Chair Stand Test in favor of the SUP group. Following detraining, significantly enhanced performances (compared to baseline) were still present in 13 variables for the SUP group and in 10 variables for the UNSUP group. Twelve weeks of BST proved to be safe (no training-related injuries) and feasible (high attendance rates of >90%). Deficits of balance and lower extremity muscle power can be
Ho, Hsin-Mei; Tseng, Ying-Hua; Hsin, Yu-Mei; Chou, Fan-Hao; Lin, Wei-Ting
The aim of this study was to explore the lived experiences of patients afflicted with spinal muscular atrophy. Existing research studies on spinal muscular atrophy address the physical and psychological effects and complications of the disease; they also provide suggestions for how to improve the current management of this disease. However, information is limited on the disease process and the lived experience of spinal muscular atrophy patients. A phenomenological approach was conducted. Through 18 in-depth interviews recorded by a pen voice recorder, this study collected data obtained from a purposive sample of nine patients from the, 'Taiwan spinal muscular atrophy Families,' between November 2010-August 2011. The audio recordings were transcribed verbatim and data were analysed using Colaizzi's steps. Four themes and eight subthemes were identified: a loss of control (loss of muscular strength and independence), breaking limitations (assistive device use and mobility design), transcending limitations (independence/autonomy and social development) and living with hope (cherishing life and self-control). The results showed that the lived experiences of the spinal muscular atrophy patients involved living with illness, transcending the self and pursuing the meaning of life. Facing a life-threatening illness, these patients made self-adjustments in their lifestyles and exerted themselves to positively cope with hardships and maintain dignity and self-control. These findings could serve as evidence-based practice resources for healthcare professionals in helping individuals and their family members gain an in-depth understanding of spinal muscular atrophy's progression and life course and assist individuals in improving self-integrity to with hope. © 2016 John Wiley & Sons Ltd.
Abian-Vicen, Javier; Castanedo, Adrián; Abian, Pablo; Gonzalez-Millan, Cristina; Salinero, Juan José; Del Coso, Juan
The aim was to analyze the influence of competitive round on muscle strength, body-fluid balance, and renal function in elite badminton players during a real competition. Body mass, jump height during a countermovement jump, handgrip force, and urine samples were obtained from 13 elite badminton players (6 men and 7 women) before and after the 2nd-round and quarterfinal matches of the national Spanish badminton championship. Sweat rate was determined by using prematch-to-postmatch body-mass change and by weighing individually labeled fluid bottles. Sweat rates were 1.04 ± 0.62 and 0.98 ± 0.43 L/h, while rehydration rate was 0.69 ± 0.26 and 0.91 ± 0.52 L/h for the 2nd round and quarterfinals, respectively. Thus, dehydration was 0.47% ± 1.03% after the 2nd round and 0.23% ± 0.43% after the quarterfinals. There were no differences in prematch-to-postmatch jump height, but jump height was reduced from 37.51 ± 8.83 cm after the 2nd-round game to 34.82 ± 7.37 cm after the quarterfinals (P badminton competition were effective to prevent dehydration. A badminton match did not affect jump height or handgrip force, but jump height was progressively reduced by the competitive round. Badminton players' renal responses reflected diminished renal flux due to the high-intensity nature of this racket sport.
Full Text Available Latent TGFβ binding proteins (LTBPs regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular dystrophy, we created transgenic mice overexpressing the protective murine allele of LTBP4 specifically in mature myofibers using the human skeletal actin promoter. Overexpression of LTBP4 protein was associated with increased muscle mass and proportionally increased strength compared to age-matched controls. In order to assess the effects of LTBP4 in muscular dystrophy, LTBP4 overexpressing mice were bred to mdx mice, a model of Duchenne muscular dystrophy. In this model, increased LTBP4 led to greater muscle mass with proportionally increased strength, and decreased fibrosis. The increase in muscle mass and reduction in fibrosis were similar to what occurs when myostatin, a related TGFβ family member and negative regulator of muscle mass, was deleted in mdx mice. Supporting this, we found that myostatin forms a complex with LTBP4 and that overexpression of LTBP4 led to a decrease in myostatin levels. LTBP4 also interacted with TGFβ and GDF11, a protein highly related to myostatin. These data identify LTBP4 as a multi-TGFβ family ligand binding protein with the capacity to modify muscle disease through overexpression.
Lamar, Kay-Marie; Bogdanovich, Sasha; Gardner, Brandon B; Gao, Quan Q; Miller, Tamari; Earley, Judy U; Hadhazy, Michele; Vo, Andy H; Wren, Lisa; Molkentin, Jeffery D; McNally, Elizabeth M
Latent TGFβ binding proteins (LTBPs) regulate the extracellular availability of latent TGFβ. LTBP4 was identified as a genetic modifier of muscular dystrophy in mice and humans. An in-frame insertion polymorphism in the murine Ltbp4 gene associates with partial protection against muscular dystrophy. In humans, nonsynonymous single nucleotide polymorphisms in LTBP4 associate with prolonged ambulation in Duchenne muscular dystrophy. To better understand LTBP4 and its role in modifying muscular dystrophy, we created transgenic mice overexpressing the protective murine allele of LTBP4 specifically in mature myofibers using the human skeletal actin promoter. Overexpression of LTBP4 protein was associated with increased muscle mass and proportionally increased strength compared to age-matched controls. In order to assess the effects of LTBP4 in muscular dystrophy, LTBP4 overexpressing mice were bred to mdx mice, a model of Duchenne muscular dystrophy. In this model, increased LTBP4 led to greater muscle mass with proportionally increased strength, and decreased fibrosis. The increase in muscle mass and reduction in fibrosis were similar to what occurs when myostatin, a related TGFβ family member and negative regulator of muscle mass, was deleted in mdx mice. Supporting this, we found that myostatin forms a complex with LTBP4 and that overexpression of LTBP4 led to a decrease in myostatin levels. LTBP4 also interacted with TGFβ and GDF11, a protein highly related to myostatin. These data identify LTBP4 as a multi-TGFβ family ligand binding protein with the capacity to modify muscle disease through overexpression.
Po'ad, F. A.; Ismail, W.; Jusoh, J. F.
This paper describes the experiments and analysis conducted on 2.4 GHz embedded active Radio Frequency Identification (RFID) - Wireless Sensor Network (WSN) based system that has been developed for the purposes of location tracking and monitoring in indoor and outdoor environments. Several experiments are conducted to test the effectiveness and performance of the developed system and two of them is by measuring the Radio Frequency (RF) transmitting power and Received Signal Strength (RSS) to prove that the embedded active RFID tag is capable to generate higher transmit power during data transmission and able to provide better RSS reading compared to standalone RFID tag. Experiments are carried out on two RFID tags which are active RFID tag embedded with GPS and GSM (ER2G); and standalone RFID tag communicating with the same active RFID reader. The developed ER2G contributes 12.26 % transmit power and 6.47 % RSS reading higher than standalone RFID tag. The results conclude that the ER2G gives better performance compared to standalone RFID tag and can be used as guidelines for future design improvements.
Chen Junjie; Liao Weixian; Zhang Zhaoxiang; Xiong Yuanbo
A mechanical model has been set up to analyze the bracket structure in the containment of a nuclear power plant. Its stress and displacement distributions were studied with both FEM and photoelastic experiments. Results of the two methods are consistent. It is shown that the rear reinforcing plate has less strengthening effect on the bracket. Therefore, several modified bracket structures were investigated and a reasonable simplified bracket is proposed here, i.e., the rear reinforcing plate is cancelled, the web is an inverted ladder-shaped plate and part of the lower wing is cut off. The new structure can meet the loading demands without any major difference from the original and may save steel, simplify manufacturing technique. It is helpful to alleviate the welding residual stress and the tendency of cracking of the welding seams. (9 figs., 9 tabs.)
Matsumura, Kiichiro; Nakano, Imaharu; Fukuda, Nobuo; Ikehira, Hiroo; Tateno, Yukio.
Proton NMR-CT (magnetic field strength 0.1 Tesla, resonant frequency 4.5 MHz) was performed in 10 normal females and 19 Duchenne muscular dystrophy (DMD) carriers. The mean age was 39 ± 12 years for the normal females and 42 ± 6 years for the DMD carriers. In DMD carriers, there were 4 definite, 4 probable, and 11 possible carriers. T 1 (spin-lattice relaxation time) image was obtained for a slice at the buttock, mid-thigh and calf levels respectively. T 1 values were measured for the medial portion of the gluteus maximus, the vastus lateralis of the quadriceps femoris, and the gastrocnemius. The bound water fraction (BWF) was calculated from Fullerton's equation based on the fast proton diffusion model. The following results were obtained: (1) In normal females, muscle T 1 value was highest in the gastrocnemius and lowest in the gluteus maximus. (2) In DMD carriers, T 1 values of the gluteus maximus and quadriceps femoris were significantly higher than those of the normal females. There was, however, no significant difference in T 1 value of the gastrocnemius between DMD carriers and normal females. (3) In DMD carriers, BWFs of the gluteus maximus and quadriceps femoris were significantly lower than those of the normal females. (4) In DMD carriers, no significant correlation was observed between the muscle T 1 values and the serum creatine phosphokinase values. Increased tissue water content in the lower parts of the body due to gravity is considered to be the primary cause of the high T 1 value in the gastrocnemius of normal females. The presence of the degenerating muscle fibers are presumed responsible for the high T 1 value and low BWF in the proximal muscles of DMD carriers. (author)
Matsumura, Kiichiro; Nakano, Imaharu; Ikehira, Hiroo; Fukuda, Nobuo; Tateno, Yukio.
Proton NMR-CT (magnetic field strength 0.1 Tesla, resonant frequency 4.5 MHz) was performed in 15 normal (NC) and 20 Duchenne muscular dystrophy (DMD) males. The age ranged from 3 to 47 years for the NC males, and 1 to 14 years for the DMD males. In the DMD group there were one subclinical stage, 4 stage 1, 6 stage 2, 4 stage 3, and 5 stage 5 or higher patients. T 1 (longitudinal relaxation) images were obtained for three slices at the buttock, midthigh, and calf levels. The T 1 values were measured for the medial portion of the gluteus maximus, the vastus lateralis of the quadriceps femoris, the adductors, the sartorius, the gracilis, and the gastrocnemius muscles. Bound water fraction (BWF) was calculated from Fullerton's equation based on the fast diffusion model. The following results were obtained: (1) In the NC group, muscle T 1 values declined gradually with maturation under the age of 10, and became constant beyond that. The average T 1 value was 280 ms for the age group between 3 and 6 years, 270 ms for 7 and 10 years, and 260 ms for those older than 10 years. (2) Muscle BWF increased with maturation in the NC group. (3) In the DMD group, T 1 values were initially higher than normal (300 ms), declined rapidly with the progress of the disease, and reached the same low level as the subcutaneous fat (190 ms). (4) This decrease of T 1 value in DMD was not uniform for all muscles, being most prominent in the gluteus maximus and least so in the sartorius and gracilis. (5) In the early stages of DMD, the BWF was lower than normal. (J.P.N.)
Paillard, Thierry; Noé, Frédéric; Passelergue, Philippe; Dupui, Philippe
Electrical stimulation (ES) reverses the order of recruitment of motor units (MU) observed with voluntary muscular contraction (VOL) since under ES, large MU are recruited before small MU. The superimposition of ES onto VOL (superimposed technique: application of an electrical stimulus during a voluntary muscle action) can theoretically activate more motor units than VOL performed alone, which can engender an increase of the contraction force. Two superimposed techniques can be used: (i) the twitch interpolation technique (ITT), which consists of interjecting an electrical stimulus onto the muscle nerve; and (ii) the percutaneous superimposed electrical stimulation technique (PST), where the stimulation is applied to the muscle belly. These two superimposed techniques can be used to evaluate the ability to fully activate a muscle. They can thus be employed to distinguish the central or peripheral nature of fatigue after exhausting exercise. In general, whatever the technique employed, the superimposition of ES onto volitional exercise does not recruit more MU than VOL, except with eccentric actions. Nevertheless, the neuromuscular response associated with the use of the superimposed technique (ITT and PST) depends on the parameter of the superimposed current. The sex and the training level of the subjects can also modify the physiological impact of the superimposed technique. Although the motor control differs drastically between training with ES and VOL, the integration of the superimposed technique in training programmes with healthy subjects does not reveal significant benefits compared with programmes performed only with voluntary exercises. Nevertheless, in a therapeutic context, training programmes using ES superimposition compensate volume and muscle strength deficit with more efficiency than programmes using VOL or ES separately.
Influence of noninvasive ventilation by BiPAP® on exercise tolerance and respiratory muscle strength in chronic obstructive pulmonary disease patients (COPD Influencia de la ventilación no evasiva mediante el BiPAP® sobre la tolerancia al ejercicio físico y fuerza muscular respiratoria en pacientes con enfermedad pulmonar obstrutiva crónica (EPOC Influência da ventilação não invasiva por meio do BiPAP® sobre a tolerância ao exercício físico e força muscular respiratória em pacientes com doença pulmonar obstrutiva crônica (DPOC
Full Text Available This study aimed to assess the effect of BiPAP®, by nasal mask, on exercise tolerance and respiratory muscle strength in patients with a clinical and spirometric diagnosis of moderate/severe COPD (FEV1 El objetivo de esto estudio fue evaluar el efecto del BiPAP®, por medio de la máscara nasal, sobre la tolerancia al ejercicio físico y el desempeño muscular respiratorio en pacientes con diagnosis clínico y espirométrico de EPOC moderada/grave (VEF1 O objetivo deste estudo foi avaliar o efeito do BiPAP®, através de máscara nasal, na tolerância ao exercício físico e no desempenho muscular respiratório em pacientes com diagnóstico clínico e espirométrico de DPOC, moderado/grave (VEF1 < 60% do previsto. Com VEF1/CVF <70% do previsto e idade média de 59,4±8,9 anos, dez pacientes com doença pulmonar obstrutiva crônica (DPOC foram tratados com 30 minutos de BiPAP® (IPAP=10-15 e EPAP=4 cmH2O, em três sessões semanais, durante dois meses. Antes e após o tratamento mediu-se a espirometria, a força muscular inspiratória (PImax e expiratória (PEmax e a distância percorrida em seis minutos (TC6. Foram constatados aumentos significativos (Wilcoxon, p<0,05 na média da PImax (de -55±17 para -77±19 cmH2O, da PEmax (de 75±20 para 109±36 cmH2O e da distância percorrida (de 349±67 para 448±75 metros. Com base nesses resultados conclui-se que o BiPAP® melhorou o desempenho muscular respiratório e a tolerância ao exercício físico nesses pacientes com DPOC.
Kanat Kambarovich Akhmetov; Irina Yurievna Chidunchi
The issue of structural organization of muscular elements of a trematodes’ skin-muscular sac is considered in the study. Special attention is paid to an analysis of materials of preceding researches, study of foreign authors and also to additional literature reflecting peculiarities of structure of a trematodes’ body muscular system. The stated issue is insufficiently studied and calls for further researches. A comparative analysis of places of trematodes’ localization, taking into considerat...
Horvat, Michael; Ray, Christopher; Nocera, Joe; Croce, Ron
For many populations the ability to move efficiently is compromised by an impaired muscular functioning. Strength development is necessary to overcome the effects of gravity to maintain posture and generate movement responses for mobility. The strength and power capabilities of individuals with total blindness (n = 12) were compared to those with partial vision (n = 12) to evaluate effects of vision on performance. Results indicate that (1) no significant differences were apparent between total blindness and partial vision, (2) significant sex differences were evident in each group, and (3) better performance was apparent at lower velocities. It was concluded that physical performance in individuals with blindness and partial vision are equally deficient.
Carroll, Kate; de Valle, Katy; Kornberg, Andrew; Ryan, Monique; Kennedy, Rachel
To report the effects of below-knee serial casting in two boys with Duchenne muscular dystrophy who presented with well-preserved strength and calf shortening. Bilateral below-knee serial casts were applied over two weeks with follow-up of daily stretching and wearing of customized night splints. Outcome measures were performed at baseline, 1, 3, 6, and 12 months post-casting. These included measures of calf length, leg strength, motor function, endurance, and spatio-temporal gait parameters. Both boys completed serial casting with gains in muscle length. No adverse effects on strength or motor function were observed over a 12-month follow-up period.
Erčulj, Frane; Blas, Mateja; Bračič, Mitja
The aim of the study was to determine and analyze the level of certain motor abilities (acceleration and agility, the explosive strength of arms, and take-off power) of young elite European female basketball players. We also wanted to establish whether there were any differences between 3 groups of female basketball players who differed in terms of their playing performance. The sample of subjects consists of 65 female basketball players aged 14.49 (± 0.61) years who were divided into 3 groups (divisions A, B, and C of the European Championships). We compare the groups by using 8 motor tests. p Values training status, this is also 1 of the key reasons for these players' lower playing efficiency compared to those from divisions A and B. We hope the findings of this study will enable the generation of model values, which can assist basketball coaches for this age category in basketball clubs, high schools, national teams, and basketball camps.
de Visser, M.; Bakker, E.; Defesche, J. C.; Bolhuis, P. A.; van Ommen, G. J.
We report on 5 brothers with slowly progressive limbgirdle weakness. Calf hypertrophy was absent. The levels of creatine kinase, electromyography, and findings from a muscle biopsy specimen were compatible with muscular dystrophy. The propositus's biopsy specimen also showed numerous rimmed
Physical Therapy & FSHD Facioscapulohumeral Muscular Dystrophy A Guide for Patients & Physical Therapists Authors: Wendy M. King, P.T., Assistant ... Shree Pandya, P.T., M.S., Assistant Professor, Neurology & Physical Medicine and Rehabilitation A publication of the FSH ...
... topic are answered in this section. How do people cope with muscular dystrophy (MD)? Although MD presents ... improve health and quality of life. Almost all people with any form of MD experience a worsening ...
McBride, Jeffrey M; Triplett-McBride, Travis; Davie, Allan; Newton, Robert U
The purpose of this investigation was to examine the effect of an 8-week training program with heavy- vs. light-load jump squats on various physical performance measures and electromyography (EMG). Twenty-six athletic men with varying levels of resistance training experience performed sessions of jump squats with either 30% (JS30, n = 9) or 80% (JS80, n = 10) of their one repetition maximum in the squat (1RM) or served as a control (C, n = 7). An agility test, 20-m sprint, and jump squats with 30% (30J), 55% (55J), and 80% (80J) of their 1RM were performed before and after training. Peak force, peak velocity (PV), peak power (PP), jump height, and average EMG (concentric phase) were calculated for the jumps. There were significant increases in PP and PV in the 30J, 55J, and 80J for the JS30 group (p squats results in increased movement velocity capabilities and that velocity-specific changes in muscle activity may play a key role in this adaptation.
Gardner, Adrian C.; Roper, Helen P.; Chikermane, Ashish A.; Tatman, Andrew J.
This study summaries the current management of scoliosis in patients with Duchenne Muscular Dystrophy. A literature review of Medline was performed and the collected articles critically appraised. This literature is discussed to give an overview of the current management of scoliosis within Duchenne Muscular Dystrophy. Importantly, improvements in respiratory care, the use of steroids and improving surgical techniques have allowed patients to maintain quality of life and improved life expectancy in this patient group. PMID:27757431
Koschate, J; Drescher, U; Baum, K; Eichberg, S; Schiffer, T; Latsch, J; Brixius, K; Hoffmann, U
Pulmonary oxygen uptake (V˙O2) kinetics and heart rate kinetics are influenced by age and fitness. Muscular V˙O2 kinetics can be estimated from heart rate and pulmonary V˙O2. In this study the applicability of a test using pseudo-random binary sequences in combination with a model to estimate muscular V˙O2 kinetics was tested. Muscular V˙O2 kinetics were expected to be faster than pulmonary V˙O2 kinetics, slowed in aged subjects and correlated with maximum V˙O2 and heart rate kinetics. 27 elderly subjects (73±3 years; 81.1±8.2 kg; 175±4.7 cm) participated. Cardiorespiratory kinetics were assessed using the maximum of cross-correlation functions, higher maxima implying faster kinetics. Muscular V˙O2 kinetics were faster than pulmonary V˙O2 kinetics (0.31±0.1 vs. 0.29±0.1 s; p=0.004). Heart rate kinetics were not correlated with muscular or pulmonary V˙O2 kinetics or maximum V˙O2. Muscular V˙O2 kinetics correlated with maximum V˙O2 (r=0.35; p=0.033). This suggests, that muscular V˙O2 kinetics are faster than estimates from pulmonary V˙O2 and related to maximum V˙O2 in aged subjects. In the future this experimental approach may help to characterize alterations in muscular V˙O2 under various conditions independent of motivation and maximal effort. © Georg Thieme Verlag KG Stuttgart · New York.
Rogers, Benjamin H; Brown, Justin C; Gater, David R; Schmitz, Kathryn H
To characterize the relationship between 1-repetition maximum (1-RM) bench press strength and isometric handgrip strength among breast cancer survivors. Cross-sectional study. Laboratory. Community-dwelling breast cancer survivors (N=295). Not applicable. 1-RM bench press strength was measured with a barbell and exercise bench. Isometric handgrip strength was measured using an isometric dynamometer, with 3 maximal contractions of the left and right hands. All measures were conducted by staff with training in clinical exercise testing. Among 295 breast cancer survivors, 1-RM bench press strength was 18.2±6.1kg (range, 2.2-43.0kg), and isometric handgrip strength was 23.5±5.8kg (range, 9.0-43.0kg). The strongest correlate of 1-RM bench press strength was the average isometric handgrip strength of both hands (r=.399; Pisometric handgrip strength of both hands overestimated 1-RM bench press strength by 4.7kg (95% limits of agreement, -8.2 to 17.6kg). In a multivariable linear regression model, the average isometric handgrip strength of both hands (β=.31; Pstrength (R 2 =.23). Isometric handgrip strength is a poor surrogate for 1-RM bench press strength among breast cancer survivors. 1-RM bench press strength and isometric handgrip strength quantify distinct components of muscular strength. Copyright © 2016 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.
Full Text Available Birte Tornøe,1,2,5,6 Lars L Andersen,3 Jørgen H Skotte,3 Rigmor Jensen,4 Gunvor Gard,1 Liselotte Skov,2 Inger Hallström1 1Department of Health Sciences, Lund University, Scania, Sweden; 2Children's Headache Clinic, Department of Pediatrics, University of Copenhagen, Herlev Hospital, Herlev, Denmark; 3National Research Centre for the Working Environment, Copenhagen, Denmark; 4Danish Headache Center, Department of Neurology, University of Copenhagen, Glostrup Hospital, Glostrup, Denmark; 5Department of Physiotherapy and Occupational Therapy, University of Copenhagen, Glostrup Hospital, Glostrup, Denmark; 6Department of Physiotherapy, Medical Department, University of Copenhagen, Herlev Hospital, Herlev, Denmark Background: Frequent or chronic tension-type headache in children is a prevalent and debilitating condition for the child, often leading to medication overuse. To explore the relationship between physical factors and tension-type headache in children, the quality of repeated measures was examined. The aim of the present study was to determine the test-retest repeatability of parameters determining isometric neck and shoulder strength and stability, aerobic power, and pericranial tenderness in children. Methods: Twenty-five healthy children, 9 to 18 years of age, participated in test-retest procedures within a 1-week interval. A computerized padded force transducer was used for testing. The tests included the isometric maximal voluntary contraction and force steadiness of neck flexion and extension, and the isometric maximal voluntary contraction and rate of force of the dominant shoulder. Pericranial tenderness was recorded by means of standardized manual palpation, and a submaximal cycle ergometer test predicted maximal oxygen uptake (VO2 max. The measurements were evaluated in steps, using the intraclass correlation coefficient (ICC; changes in the mean between the two test occasions; the levels of agreement, visualized in Bland
Brumitt, Jason W; Essman, Stephanie C; Kornegay, Joe N; Graham, John P; Weber, William J; Berry, Clifford R
Golden Retriever muscular dystrophy is an inherited, degenerative myopathy due to the absence of dystrophin and is used as a model of Duchenne muscular dystrophy of young boys. This report describes the radiographic abnormalities of Golden Retriever muscular dystrophy in 26 dogs. The thoracic abnormalities included diaphragmatic asymmetry (18/26), diaphragmatic undulation (18/26), and gastro-esophageal hiatal hernia (6/26). Pelvic abnormalities included narrowing of the body of the ilia (14/19), ventral deviation and curvature of the tuber ischii (14/19), elongation of the obturator foramen with a decrease in opacity of the surrounding bone (12/19), and lateral flaring of the wings of the ilia (12/19). Abdominal abnormalities consisted of hepatomegaly (14/22) and poor serosal detail (12/22). The unique thoracic abnormalities were a consistent finding in affected Golden Retriever muscular dystrophy dogs. The diagnosis of muscular dystrophy should be included in the differential list if the combination of diaphragm undulation and asymmetry, and gastro-esophageal hiatal hernia are identified. These diaphragmatic abnormalities are related to hypertrophy and hyperplasia of the diaphragm. Additionally, the skeletal changes of pelvic tilt, elongation of the pelvis, widening of the obturator foramina and thinning of the ischiatic tables appear to be specific to Golden Retriever muscular dystrophy in dogs. These pelvic abnormalities are most likely secondary to bone remodeling associated with the progressive skeletal myopathy and subsequent contracture/fibrosis.
Wilson, Jacob M; Flanagan, Eamonn P
The purpose of this article is to provide strength and conditioning practitioners with an understanding of the role of elastic energy in activities with high force and power requirements. Specifically, the article covers 1) the nature of elasticity and its application to human participants, 2) the role of elastic energy in activities requiring a stretch-shorten cycle such as the vertical jump, 3) the role of muscular stiffness in athletic performance, 4) the control of muscular stiffness through feedforward and feedback mechanisms, and 5) factors affecting muscular stiffness. Finally, practical applications are provided. In this section, it is suggested that the storage and reuse of elastic energy is optimized at relatively higher levels of stiffness. Because stiffness decreases as fatigue ensues as well as with stretching before an event, the article emphasizes the need for proper preparation phases in a periodized cycle and the avoidance of long static stretches before high-force activities. The importance of teaching athletes to transition from eccentric to concentric movements with minimal time delays is also proposed due to the finding that time delays appear to decrease the reuse of elastic energy. In addition to teaching within the criterion tasks, evidence is provided that minimizing transitions in plyometric training, a technique demonstrated to increase musculotendinous stiffness, can optimize power output in explosive movements. Finally, evidence is provided that training and teaching programs designed to optimize muscular stiffness may protect athletes against sports-related injuries.
Lieberman, Andrew P
Spinal and bulbar muscular atrophy (SBMA) is an adult-onset degenerative disorder of the neuromuscular system resulting in slowly progressive weakness and atrophy of the proximal limb and bulbar muscles. The disease is caused by the expansion of a CAG/glutamine tract in the amino-terminus of the androgen receptor. That SBMA exclusively affects males reflects the fact that critical pathogenic events are hormone-dependent. These include translocation of the polyglutamine androgen receptor from the cytoplasm to the nucleus and unfolding of the mutant protein. Studies of the pathology of SBMA subjects have revealed nuclear aggregates of the mutant androgen receptor, loss of lower motor neurons in the brainstem and spinal cord, and both neurogenic and myopathic changes in skeletal muscle. Mechanisms underlying disease pathogenesis include toxicity in both lower motor neurons and skeletal muscle, where effects on transcription, intracellular transport, and mitochondrial function have been documented. Therapies to treat SBMA patients remain largely supportive, although experimental approaches targeting androgen action or promoting degradation of the mutant androgen receptor protein or the encoding RNA are under active study. Copyright © 2018 Elsevier B.V. All rights reserved.
Faigenbaum, A D
The potential benefits of youth strength training extend beyond an increase in muscular strength and may include favorable changes in selected health- and fitness-related measures. If appropriate training guidelines are followed, regular participation in a youth strength-training program has the potential to increase bone mineral density, improve motor performance skills, enhance sports performance, and better prepare our young athletes for the demands of practice and competition. Despite earlier concerns regarding the safety and efficacy of youth strength training, current public health objectives now aim to increase the number of boys and girls age 6 and older who regularly participate in physical activities that enhance and maintain muscular fitness. Parents, teachers, coaches, and healthcare providers should realize that youth strength training is a specialized method of conditioning that can offer enormous benefit but at the same time can result in serious injury if established guidelines are not followed. With qualified instruction, competent supervision, and an appropriate progression of the volume and intensity of training, children and adolescents cannot only learn advanced strength training exercises but can feel good about their performances, and have fun. Additional clinical trails involving children and adolescents are needed to further explore the acute and chronic effects of strength training on a variety of anatomical, physiological, and psychological parameters.
Cliff Jolly developed a causal model of human origins in his paper "The Seed-Eaters," published in 1970. He was one of the first to attempt this, and the paper has since become a classic. I do not have such grand goals; instead, I seek to understand a major difference between the living great apes and humans. More than 50 years ago, Maynard Smith and Savage (1956) showed that the musculoskeletal systems of mammals can be adapted for strength at one extreme and speed at the other but not both. Great apes are adapted for strength--chimpanzees have been shown to be about four times as strong as fit young humans when normalized for body size. The corresponding speed that human limb systems gain at the expense of power is critical for effective human activities such as running, throwing, and manipulation, including tool making. The fossil record can shed light on when the change from power to speed occurred. I outline a hypothesis that suggests that the difference in muscular performance between the two species is caused by chimpanzees having many fewer small motor units than humans, which leads them, in turn, to contract more muscle fibers earlier in any particular task. I outline a histological test of this hypothesis.
Sveen, Marie-Louise; Thune, Jens Jakob; Køber, Lars
OBJECTIVE: To investigate the extent of cardiac involvement in patients with 1 of the 12 groups of recessively inherited limb-girdle muscular dystrophy type 2 (LGMD2A-L) and Becker muscular dystrophy (BMD). DESIGN: Prospective screening. SETTING: Neuromuscular Clinic and Department of Cardiology...
Full Text Available Duchenne muscular dystrophy (DMD, clinically featured as progressive skeletal muscle atrophy with gradual loss of muscle strength and activity abilities, is the most common genetic muscular disease in children throughout the world. The core and continuous characteristic of DMD is motor dysfunction. Motor function assessments of DMD are now focusing on muscle strength, walking ability, range of motion and ability of activities, still without unified standards. Confirming the comprehensive, scientific, reasonable and accurate evaluation tools for DMD assessment is the premise of research in motor developmental rules of DMD, which will help to better understand the motor progress of DMD and to supply evidences for choosing treatment methods, confirming timing of intervention, assessing effect of treatments and designing rehabilitation plans. DOI: 10.3969/j.issn.1672-6731.2015.06.002
Recruitment rate, feasibility and safety of power training in individuals with Parkinson's disease: a proof-of-concept study Taxa de recrutamento, viabilidade e segurança de um treinamento de potência muscular em indivíduos com doença de Parkinson: um estudo prova de conceito
Lidiane O. Lima
Full Text Available BACKGROUND: It has been suggested that power training should be implemented in interventions in Parkinson's disease (PD. However, it is necessary to determine the feasibility and safety of training rapid movements in such individuals. OBJECTIVES: To determine the rate of recruitment of potential participants, the rate of attendance at training sessions, the levels of adherence to the intervention, and the rate of adverse events. METHOD: Patients with PD, users of the national public health system underwent power training of the lower limb muscles three times a week for 10 weeks. The number of people who were screened and recruited was recorded, as well as the rate of attendance at the training sessions and adherence to the intervention protocol. Safety was assessed by the presence of adverse events, pain, number of falls, and risk of injury associated with the intervention. RESULTS: Over the course of eight months, 62 individuals were screened and only 13 completed the program. The rates of attendance and adherence were 88% and 97%, respectively. There were no adverse events during training. Two participants reported joint pain and one reported falls during the training period. CONCLUSIONS: The recruitment rate was low due to the subjects' difficulties with transportation and lack of interest. The high rates of adherence and attendance and the absence of adverse events suggest that power training is feasible and safe in PD.CONTEXTUALIZAÇÃO: Sugeriu-se que treinamento de potência muscular deve ser implementado em programas de exercícios na doença de Parkinson (DP. Entretanto, há necessidade de se determinar a viabilidade e a segurança associadas ao treinamento de movimentos rápidos em tais indivíduos. OBJETIVOS: Determinar a taxa de recrutamento dos participantes; a taxa de presença nas sessões de treinamento; o nível de adesão ao protocolo de intervenção e a taxa de eventos adversos relacionados. MÉTODO: Indivíduos com DP, usu
Winwood, Paul W; Keogh, Justin W L; Harris, Nigel K
This study describes the results of a survey of the strength and conditioning practices of strongman competitors. A 65-item online survey was completed by 167 strongman competitors. The subject group included 83 local, 65 national, and 19 international strongman competitors. The survey comprised 3 main areas of enquiry: (a) exercise selection, (b) training protocols and organization, and (c) strongman event training. The back squat and conventional deadlift were reported as the most commonly used squat and deadlift (65.8 and 88.0%, respectively). Eighty percent of the subjects incorporated some form of periodization in their training. Seventy-four percent of subjects included hypertrophy training, 97% included maximal strength training, and 90% included power training in their training organization. The majority performed speed repetitions with submaximal loads in the squat and deadlift (59.9 and 61.1%, respectively). Fifty-four percent of subjects incorporated lower body plyometrics into their training, and 88% of the strongman competitors reported performing Olympic lifts as part of their strongman training. Seventy-eight percent of subjects reported that the clean was the most performed Olympic lift used in their training. Results revealed that 56 and 38% of the strongman competitors used elastic bands and chains in their training, respectively. The findings demonstrate that strongman competitors incorporate a variety of strength and conditioning practices that are focused on increasing muscular size, and the development of maximal strength and power into their conditioning preparation. The farmers walk, log press, and stones were the most commonly performed strongman exercises used in a general strongman training session by these athletes. These data provide information on the training practices required to compete in the sport of strongman.
Full Text Available Abstract Background Hydatidosis is a zoonosis caused by Echinococcus granulosus, and ingesting eggs released through the faeces from infected dogs infects humans. The location of the hydatid cysts is mostly hepatic and/or pulmonary, whereas musculoskeletal hydatidosis is very rare. Case presentation We report an unusual case of primary muscular hydatidosis in proximity of the big adductor in a young Sicilian man. The patient, 34 years old, was admitted to the Department of Infectious and Tropical Diseases for ultrasonographic detection, with successive confirmation by magnetic resonance imaging, of an ovular mass (13 × 8 cm in the big adductor of the left thigh, cyst-like, and containing several small cystic formations. Serological tests for hydatidosis gave negative results. A second drawing of blood was done 10 days after the first one and showed an increase in the antibody titer for hydatidosis. The patient was submitted to surgical excision of the lesion with perioperatory prophylaxis with albendazole. The histopathological examination of the bioptic material was not diriment in the diagnosis, therefore further tests were performed: additional serological tests for hydatidosis for the evaluation of IgE and IgG serotype (Western Blot and REAST, and molecular analysis of the excised material. These more specific serological tests gave positive results for hydatidosis, and the sequencing of the polymerase chain reaction products from the cyst evidenced E. granulosus DNA, genotype G1. Any post-surgery complications was observed during 6 following months. Conclusion Cystic hydatidosis should always be considered in the differential diagnosis of any cystic mass, regardless of its location, also in epidemiological contests less suggestive of the disease. The diagnosis should be achieved by taking into consideration the clinical aspects, the epidemiology of the disease, the imaging and immunological tests but, as demonstrated in this case, without
Correa, Cleiton S; Cunha, Giovani; Marques, Nise; Oliveira-Reischak, Ãlvaro; Pinto, Ronei
Previous studies presented different results regarding the maintenance time of muscular adaptations after strength training and the ability to resume the gains on muscular performance after resumption of the training programme. This study aimed to verify the effect of strength training on knee extensors and elbow flexor muscle strength, rectus femoris muscle volume and functional performance in older female adults after 12 weeks of strength training, 1 year of detraining and followed by 12 weeks of retraining. Twelve sedentary older women performed 12 weeks of strength training, 1 year of detraining and 12 weeks of retraining. The strength training was performed twice a week, and the assessment was made four times: at the baseline, after the strength training, after the detraining and after the retraining. The knee extensor and elbow flexor strength, rectus femoris muscle volume and functional task were assessed. Strength of knee extensor and elbow flexor muscles, rectus femoris muscle volume and 30-s sit-to-stand increased from baseline to post-training (respectively, 40%, 70%, 38% and 46%), decreased after detraining (respectively, -36%, -64%, -35% and -43%) and increased again these parameters after retraining (35%, 68%, 36% and 42%). Strength training induces gains on strength and hypertrophy, also increased the performance on functional tasks after the strength training. The stoppage of the strength caused strength loss and reduction of functional performance. The resumption of the strength training promoted the same gains of muscular performance in older female adults. © 2015 Scandinavian Society of Clinical Physiology and Nuclear Medicine. Published by John Wiley & Sons Ltd.
Grandys, M; Majerczak, J; Kulpa, J; Duda, K; Rychlik, U; Zoladz, J A
Acute exercise-induced changes in cortisol concentration (C) and training related adaptation within hypothalamic-pituitary-adrenal (HPA) axis has been widely examined, but their influence on muscle strength performance is at best uncertain. Twenty four young healthy men were randomly assigned to an endurance training group (ET, n=12) or to a non-exercising controls (CON, n=12). ET performed supervised endurance training on cycle ergometer for 20 weeks. Endurance training program improved exercise capacity (14 % increase in power output generated at peak oxygen uptake - VO(2peak)), muscle strength performance (increase in MVC - maximal voluntary contraction - by 9 % and in TTF 50 % MVC - time to fatigue at 50 % MVC - by 21 %) and led to a decrease in basal serum C concentration (P=0.006) and an increase in basal testosterone to cortisol (T/C) and free testosterone to cortisol (fT/C) ratios (P=0.01 and P=0.02, respectively). It was found that the decrease in C concentration (deltaC) was positively correlated to the increase in local muscular endurance (deltaTTF 50 % MVC). No significant hormonal changes were seen in CON group. It is concluded that greater decrease in cortisol concentration after the endurance training is accompanied by poorer improvement in skeletal muscle performance in previously untrained subjects.
Full Text Available By measuring very early changes in muscle strength and functional performance after fast-track total hip arthroplasty (THA, post-operative rehabilitation, introduced soon after surgery, can be designed to specifically target identified deficits.Firstly, to quantify changes (compared to pre-operative values in hip muscle strength, leg-press power, and functional performance in the first week after THA, and secondly, to explore relationships between the muscle strength changes, and changes in hip pain, systemic inflammation, and thigh swelling.Prospective, cohort study.Convenience sample of patients receiving a THA at Copenhagen University Hospital, Hvidovre, Denmark, between March and December 2011.Thirty-five patients (65.9 ± 7.2 years undergoing THA.Hip muscle strength, leg-press power, performance-based function, and self-reported disability were determined prior to, and 2 and 8 days after, THA (Day 2 and 8, respectively. Hip pain, thigh swelling, and C-Reactive Protein were also determined.Five patients were lost to follow-up. Hip muscle strength and leg press power were substantially reduced at Day 2 (range of reductions: 41-58%, P<0.001, but less pronounced at Day 8 (range of reductions: 23-31%, P<0.017. Self-reported symptoms and function (HOOS: Pain, Symptoms, and ADL improved at Day 8 (P<0.014. Changes in hip pain, C-Reactive Protein, and thigh swelling were not related to the muscle strength and power losses.Hip muscle strength and leg-press power decreased substantially in the first week after THA - especially at Day 2 - with some recovery at Day 8. The muscle strength loss and power loss were not related to changes in hip pain, systemic inflammation, or thigh swelling. In contrast, self-reported symptoms and function improved. These data on surgery-induced changes in muscle strength may help design impairment-directed, post-operative rehabilitation to be introduced soon after surgery.ClinicalTrials.gov NCT01246674.
Andersen, Grete; Dahlqvist, Julia R; Vissing, Christoffer R
There is no effective treatment available for facioscapulohumeral muscular dystrophy type 1 (FSHD1), but emerging therapies are under way that call for a better understanding of natural history in this condition. In this prospective, longitudinal study, we used quantitative MRI to assess yearly...... disease progression in patients with FSHD1. Ambulatory patients with confirmed diagnosis of FSHD1 (25/20 men/women, age 20-75 years, FSHD score: 0-12) were tested with 359-560-day interval between tests. Using the MRI Dixon technique, muscle fat replacement was evaluated in paraspinal, thigh, and calf...... muscles. Changes were compared with those in FSHD score, muscle strength (hand-held dynamometry), 6-minute-walk-distance, 14-step-stair-test, and 5-time-sit-to-stand-test. Composite absolute fat fraction of all assessed muscles increased by 0.036 (CI 0.026-0.046, P
Shefner, Jeremy M
Loss of muscle strength is a cardinal feature of all motor neuron diseases. Functional loss over time, including respiratory dysfunction, inability to ambulate, loss of ability to perform activities of daily living, and others are due, in large part, to decline in strength. Thus, the accurate measurement of limb muscle strength is essential in therapeutic trials to best understand the impact of therapy on vital function. While qualitative strength measurements show declines over time, the lack of reproducibility and linearity of measurement make qualitative techniques inadequate. A variety of quantitative measures have been developed; all have both positive attributes and limitations. However, with careful training and reliability testing, quantitative measures have proven to be reliable and sensitive indicators of both disease progression and the impact of experimental therapy. Quantitative strength measurements have demonstrated potentially important therapeutic effects in both amyotrophic lateral sclerosis and spinobulbar muscular atrophy, and have been shown feasible in children with spinal muscular atrophy. The spectrum of both qualitative and quantitative strength measurements are reviewed and their utility examined in this review.
Schapira, G; Dreyfus, J C; Schapira, F
Two hereditary muscular dystrophies similar to human progressive muscular dystrophy (P.M.D. Duchenne type) have been isolated in animals, one in mouse, the other in chicken. The decrease in the activity of glycogenolytic enzymes is similar to that observed in denervated muscle. Isozymic fetal types for several muscular enzymes have been observed as well in chicken as in man, but this fetal type may also be found in neurogenic atrophy. The release in circulation of muscle enzymes seems more specific. But the origin of the genetic lesion is still unknown. We describe here the three different theories about this problem: i.e. neurogenic, vascular, or myogenic. This last theory implies a trouble of membrane permeability.
D. A. Kharlamov
Full Text Available The literature review gives data on the role of mitochondrial disorders in the pathogenesis of different progressive muscular dystrophies. It describes changes in Duchenne, limb-girdle, facial scapulohumeral (Landuzi—Degerina muscular dystrophies. The review is based on both clinical and experimental animal studies. Along with the implication o