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Muscular Strength (muscular + strength)
Selected AbstractsThe aging male , diagnosis and therapy of late-onset hypogonadismJOURNAL DER DEUTSCHEN DERMATOLOGISCHEN GESELLSCHAFT, Issue 4 2008Gerhard Schreiber Summary Managing the clinical features of hormone insufficiency in aging men is an important field of activity for dermatologists and in particular for dermatologists specialized in andrology. Potential consequences of age-associated decrease in plasma testosterone levels include long-term changes in diverse organ systems including changes of bone architecture, body composition, muscular strength, cognitive functions, and mood as well as negative effects on skin and hair. Indications and contraindications for a hormone replacement therapy as well as therapy monitoring are well-defined. Replacement of testosterone in the case of late-onset hypogonadism is not a standardized therapy. Previous studies suggest that testosterone replacement therapy has positive clinical effects. Dermatologic effects of testosterone replacement therapy have not yet been investigated. Further research is required to identify potential benefits and risks of hormone replacement therapy in aging men. [source] Low Serum Vitamin D Does Not Predict New Disability or Loss of Muscle Strength in Older WomenJOURNAL OF AMERICAN GERIATRICS SOCIETY, Issue 5 2002René Verreault MD OBJECTIVES: To determine whether serum levels of 25-hydroxyvitamin D (25(OH)D) and parathyroid hormone (PTH) predict accelerated decline in muscular strength or onset of new disability in mobility and upper extremity functioning over a 3-year follow-up. DESIGN: A community-based prospective cohort study. PARTICIPANTS: Six hundred twenty-eight moderately to severely disabled women aged 65 and older living in the community. MEASUREMENTS: Subjects were divided into three groups of baseline 25(OH)D serum levels (deficiency: <25 nmol/L; low normal: 25,52 nmol/L; high normal: ,53 nmol/L) and into tertiles of PTH levels. Objective performance measures (hip flexor, knee extensor, and grip strengths; walking speed; and time for repeated chair stands) and disability in activities involving mobility and upper extremity function were assessed at baseline and every 6 months for 3 years. Decline in performance measures and onset of new disability were compared between 25(OH)D and PTH groups using random effects models and proportional hazards models, respectively, while adjusting for age, race, education, body mass index, baseline performance, and chronic conditions. RESULTS: The annual rate of decline over 3 years in muscular strength, walking speed, and time to perform repeated chair stands was similar across 25(OH)D groups. We observed a nonsignificantly faster decline in proximal muscle strength and walking speed with increasing PTH levels. There was no association for either measure between serum levels and the risk of incident disability in activities relating to mobility and upper extremity function. CONCLUSION: This study does not support the hypothesis that vitamin D deficiency is associated with loss in muscular strength and decline in mobility and upper extremity functioning over time in older women who were moderately to severely disabled at baseline. [source] Dynamic postural stability during sit-to-walk transitions in Parkinson disease patientsMOVEMENT DISORDERS, Issue 9 2008Thomas A. Buckley EdD Abstract In an effort to further our understanding of postural control in Parkinson's disease, we biomechanically evaluated the sit to walk task and its component tasks, sit to stand (STS) and gait initiation (GI) in 12 healthy older adults and 12 persons with Parkinson's disease (PWP). Performance was evaluated utilizing motion capture and two force plates. The major finding of this study was the inability of the PWP to appropriately merge the sequential component tasks (STS and GI) during STW. The PWP rose to nearly full height and had a longer delay between seat-off and gait initiation (P = 0.003 and P < 0.001, respectively) during STW. Additionally, the PWP moved with slower velocities leading to shorter, slower steps and decreased separation of the center of mass and center of pressure. These observed motor sequencing disturbances may be due to a disease related disability or limitations in proprioception, movement speed, muscular strength, and reduced general mobility. © 2008 Movement Disorder Society [source] Improving health through youth sports: Is participation enough?NEW DIRECTIONS FOR YOUTH DEVELOPMENT, Issue 115 2007Michael F. Bergeron The health benefits of engaging in regular physical activity are widely known: enhanced cardiorespiratory fitness, increased muscular strength and endurance, and favorable cholesterol and other profiles. Nevertheless, particularly in youth sports programs run by volunteer, and perhaps inadequately trained, coaches, many youth may not realize the health benefits of sports participation due to a number of factors, among them, inappropriate coach-child ratios, limited space, or mismatched expectations between coaches and those of children and their parents. There are specific strategies that can be implemented to ensure that youth receive the maximize benefits from participation in sports. These strategies are presented in the following areas: frequency, intensity, and duration; cross-training or complementary exercise; access points; utilization of space and time; nutrition; and rest. For instance, with regard to the frequency of physical activity, some sports, including soccer, basketball, and singles tennis, require extensive physical effort over an extended period of time, while others, such as baseball and football, have a lot of downtime. Thus, in order for children and youth to meet the recommendation of participating in moderate or vigorous physical activity at least four times per week, sports programs need to have opportunities for all athletes to practice hard. Finally, the author discusses the point at which participation in sports might be too much, leading to significant injuries, frustration, and resentment. [source] Creatine supplementation for patients with COPD receiving pulmonary rehabilitation: A systematic review and meta-analysisRESPIROLOGY, Issue 5 2010Fahad AL-GHIMLAS ABSTRACT Background and objective: Creatine improves muscle strength in exercising healthy individuals, and in patients with neuromuscular disease and heart failure. The aim of this study was to assess whether creatine supplementation improves pulmonary rehabilitation (PR) outcomes in patients with COPD. Methods: A systematic review and meta-analysis was performed of randomized controlled trials published between January 1966 and February 2009 that evaluated the effect of creatine compared with placebo on exercise capacity, muscle strength and health-related quality of life (HR-QoL) in patients undergoing PR for COPD. The pooled estimates were expressed as mean differences (MD) or standardized mean differences (SMD). Results: Four randomized controlled trials that included 151 patients were identified. There was no effect of creatine supplementation on exercise capacity (SMD ,0.01, 95% CI: ,0.42 to 0.22, n = 151). Creatine supplementation did not improve lower extremity muscle strength (SMD 0.03, 95% CI: ,0.55 to 0.61, n = 140) or upper limb muscular strength (SMD 0.02, 95% CI: ,0.33 to 0.38, n = 128) compared with placebo. Two studies (n = 48) assessed quality of life using the St. George's Respiratory Disease Questionnaire. There were no differences in HR-QoL according to domain or total scores. Overall, creatine appeared to be safe and was well tolerated. Quality assessment of the studies showed important limitations. Conclusions: Creatine supplementation does not improve exercise capacity, muscle strength or HR-QoL in patients with COPD receiving PR. However, important limitations were identified in the quality of the available evidence, suggesting that further research is required in this area. [source] Effects of nest temperature and moisture on phenotypic traits of hatchling snakes (Tropidonophis mairii, Colubridae) from tropical AustraliaBIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 1 2006GREGORY P. BROWN Previous research on developmentally plastic responses by reptile embryos has paid relatively little attention to tropical species, or to possible interactions between the effects of thermal and hydric regimes. In the present study, eggs of keelback snakes (Tropidonophis mairii), from a tropical area with strong temporal and spatial variation in soil temperatures and moisture levels, were incubated. The phenotypic traits of hatchling snakes (body size, shape, muscular strength) were affected by moisture content of the incubation medium (vermiculite plus 100% vs. 50% water by mass), by mean incubation temperatures (25.7 vs. 27.9 °C) and by diel thermal variation (diel range 6.0 vs. 8.4 °C). Interactions between these factors were negligible. Cooler, more thermostable, moister conditions resulted in larger offspring, a trait under strong selection in this population. Thermal and hydric conditions covary in potential nest-sites (e.g. deeper nests are more thermostable as well as moister). This covariation may influence the evolution of reaction norms for embryogenesis. For example, if moister nests enhance offspring fitness and are cooler, then selection will favour the ability to develop in cool as well as moist conditions. Thus, the evolution of optimal incubation conditions with respect to one variable (e.g. temperature) may be driven by patterns of association with another variable (e.g. soil moisture) among natural nest-sites. Perhaps for this reason, the thermal optimum for incubation is surprisingly low in this tropical species. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 89, 159,168. [source] Terrestrial locomotion in sea snakes: the effects of sex and species on cliff-climbing ability in sea kraits (Serpentes, Elapidae, Laticauda)BIOLOGICAL JOURNAL OF THE LINNEAN SOCIETY, Issue 4 2005X. BONNET Ecomorphological theory predicts a match between an organism's environment and its locomotor abilities, such that animals function most effectively under the conditions they experience in nature. However, amphibious species must simultaneously optimize performance in two different habitats posing incompatible demands on locomotor morphology and physiology. This situation may generate a mismatch between environment and locomotor function, with performance optimized only for the more important habitat type; alternatively, selection may fine-tune locomotor abilities for both types of challenges. Two species of sea kraits in New Caledonia offer an opportunity to examine this question: Laticauda laticaudata is more highly aquatic than L. colubrina, and males are more terrestrial than females within each taxon. We examined an aspect of locomotor performance that is critical to coming ashore on steep-walled rocky islets: the ability to climb steep cliffs. We also measured the muscular strength of these animals, a character that is likely critical to climbing performance. Laticauda colubrina was heavier-bodied and stronger (even relative to its body mass) than the more aquatic L. laticaudata; and within each species, males were heavier-bodied and stronger than females. The same patterns were evident in cliff-climbing ability. Thus, the ability of different species and sexes of sea kraits to climb steep cliffs correlates with their body shape even though these primarily aquatic animals use terrestrial habitats only rarely. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society, 2005, 85, 433,441. [source] Effect of exercise on upper extremity pain and dysfunction in head and neck cancer survivorsCANCER, Issue 1 2008A randomized controlled trial Abstract BACKGROUND. Shoulder pain and disability are well recognized complications associated with surgery for head and neck cancer. This study was designed to examine the effects of progressive resistance exercise training (PRET) on upper extremity pain and dysfunction in postsurgical head and neck cancer survivors. METHODS. Fifty-two head and neck cancer survivors were assigned randomly to PRET (n = 27) or a standardized therapeutic exercise protocol (TP) (n = 25) for 12 weeks. The primary endpoint was change in patient-rated shoulder pain and disability from baseline to postintervention. Secondary endpoints were upper extremity strength and endurance, range of motion, fatigue, and quality of life. RESULTS. Follow-up assessment for the primary outcome was 92%, and adherence to the supervised PRET and TP programs were 95% and 87%, respectively. On the basis of intention-to-treat analyses, PRET was superior to TP for improving shoulder pain and disability (,9.6; 95% confidence interval [95% CI], ,16.4 to ,4.5; P = .001), upper extremity strength (+10.8 kg; 95% CI, 5.4,16.2 kg; P < .001), and upper extremity endurance (+194 repetitions × kg; 95% CI, 10,378 repetitions × kg; P = .039). Changes in neck dissection impairment, fatigue, and quality of life favored the PRET group but did not reach statistical significance. CONCLUSIONS. The PRET program significantly reduced shoulder pain and disability and improved upper extremity muscular strength and endurance in head and neck cancer survivors who had shoulder dysfunction because of spinal accessory nerve damage. Clinicians should consider the addition of PRET in the rehabilitation of postsurgical head and neck cancer survivors. Cancer 2008. © 2008 American Cancer Society. [source] Effects of detraining on muscle strength and mass after high or moderate intensity of resistance training in older adultsCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 4 2009Savvas P. Tokmakidis Summary This study examined the effects of a 12 weeks detraining period on muscle strength and mass in older adults who had previously participated in a 12 weeks resistance training programme of high [80% of one repetition maximum (1-RM)] or moderate (60% of 1-RM) intensity. Twenty older adults (60,74 years), separated into a high (HI; n = 10; age: 65 ± 5 years) and a moderate (MI; n = 10; age: 66 ± 4 years) intensity resistance training group, were measured in the 1-RM knee extension and flexion strength, and the midthigh cross sectional areas (CSAs) of quadriceps, hamstrings and total thigh before and after a 12 weeks training period as well as after a 12 weeks detraining period. Maximum knee extension and flexion strength and the CSAs of all muscles decreased significantly (P<0·05) with detraining but remained higher (P<0·05) than pretraining levels for both groups. The HI group had a greater decrement (P<0·05) in maximum strength and the CSA of total thigh compared to the MI group but strength levels and the CSA following detraining were higher (P<0·05) for the HI group. The above data suggest that after a short detraining period of 12 weeks, muscle strength and hypertrophy levels of older adults decrease but remain greater than pretraining irrespective of training intensity. Greater declines in muscle strength are observed following HI training but still muscular strength and muscle mass are retained at a higher level than with MI probably due to the higher gains achieved during the training period. [source] |