Skeletal muscle force production following repetitive contractions is preferentially reduced when muscle is evaluated with low-frequency stimulation. This selective impairment in force generation is called low-frequency fatigue (LFF) and could be dependent on the contraction type. The purpose of this study was to compare LFF after concentric and eccentric maximal and submaximal contractions of knee extensor muscles. Ten healthy male subjects (age: 23.6 ± 4.2 years; weight: 73.8 ± 7.7 kg; height: 1.79 ± 0.05 m) executed maximal voluntary contractions that were measured before a fatigue test (pre-exercise), immediately after (after-exercise) and after 1 h of recovery (after-recovery). The fatigue test consisted of 60 maximal (100%) or submaximal (40%) dynamic concentric or eccentric knee extensions at an angular velocity of 60°/s. The isometric torque produced by low- (20 Hz) and high- (100 Hz) frequency stimulation was also measured at these times and the 20:100 Hz ratio was calculated to assess LFF. One-way ANOVA for repeated measures followed by the Newman-Keuls post hoc test was used to determine significant (P < 0.05) differences. LFF was evident after-recovery in all trials except following submaximal eccentric contractions. LFF was not evident after-exercise, regardless of exercise intensity or contraction type. Our results suggest that low-frequency fatigue was evident after submaximal concentric but not submaximal eccentric contractions and was more pronounced after 1-h of recovery.

Introduction Iontophoresis is a noninvasive technique used to increase transdermal penetration of substances through the skin layer (epidermis, dermis and hypodermis) in a controlled manner. Technological advance in recent decades have provided reduced cost of equipment needed for implementation, which allowed for the expansion of this technique. Objective The aim of this paper is to present the state of the art on iontophoresis, ranging from the atomic characteristics of the ion formation to the current applications of the technique. Methods Were researched papers from databases: IOP publishing, ScienceDirect, Pubmed, Springer, IEEE Xplore, Google Scholar and books with keywords iontophoresis, ions, topical applications between 1967 and 2010. Results Were selected (number of papers and database) 1 IOP Publishing, 1 from ScienceDirect, Central, 1 from Springer, 2 from PubMed, 11 from IEEE Xplore, 35 from Google Scholar, and 15 books, totaling 66 references and websites with nationally marketed electrotherapy products. Conclusion Iontophoresis is suitable for applications such as acetic acid (calcific tendinitis and myositis ossificans), calcium chloride and magnesium sulfate (control of musculoskeletal spasms), dexamethasone (inflammation), lidocaine (inflammation of soft tissues), zinc oxide (rheumatoid arthritis). It is also used in cosmetic applications with devices attached to the skin and for eye treatment aimed at specific tissues of the eye, providing a treatment option for various eye diseases, reducing the complications secondary to traditional methods of treatment. The advantages are the significant increase in the release and control of therapeutic agents, including drugs with high molecular weight. The disadvantages of iontophoresis are the complexity of the drug release system and prolonged exposure of the skin to an electrical current.

In a time of instability caused by adolescence, sport may represent a resource to prevent future individual and social problems. Within the complex relationships developed in social sports contexts, the figure of the coach can be fundamental for the development of a beneficial environment. The objective of the research was to investigate the relationship between the teaching methods and leadership profile of the coach and outcomes on the perception of positive development of young people participating in an after school sports program. In total participated, 910 adolescents (14.0 ± 1.8 years) and 57 coaches (45.57 ± 7.25 years) in 37 public schools in the city of Curitiba, in the state of Paraná-Brazil. Ordinal logistic regression was used to verify the independent associations between the variables sex, category, sport, trainer methodology, perception of the coaches, and perception of the athletes with the tertiles of the scores of each developmental characteristic of the young athletes (personal and social skills, cognitive skills, goal setting, and initiative). Odds ratios (OR) were obtained with a 95% confidence interval (95%CI), adopting p < 0.05. The small sized games method were positively associated with cognitive skills and goal setting. Positive associations were also found between athletes’ perceptions of the leadership profile of coaches with: personal and social skills (instructor, democratic behaviour, social support, and positive feedback), cognitive skills (instructor, democratic behaviour, and social support), goal setting (instructor, social support, and positive feedback), and initiative (instructor and positive feedback). In addition, the athletes’ perception of the coaches’ autocratic behaviour was inversely associated with personal and social skills and goal setting. For the evaluated program, the results suggest the choice, on the part of the coaches, of small sized games, combined with a democratic, affective, motivating leadership profile that provides instructions on technical skills and game strategies. The combination of the designated psych-pedagogical aspects is correlated to the positive development of young people through team sports.

INTRODUCTION: PediaSuit ProtocolTM is an intensive therapy with a holistic approach to the treatment of individuals with neurological disorders like cerebral palsy (CP), developmental delays, traumatic brain injuries, autism and other conditions which affect a child's motor and/or cognitive functions. OBJECTIVE: The aim of the present work is to describe the PediaSuit ProtocolTM. METHODS: The authors team remained two months observing the care provided in a clinic with physical therapists trained by the PediaSuit ProtocolTM team (USA). RESULTS: The PediaSuitTM is a therapeutic protocol which uses a suit combined with intensive physical therapy and consists of up to four hours of therapy a day, five days a week, during three or four weeks. The PediaSuit ProtocolTM is customized to fit the needs of each child, with specific functional goals, and usually involves an intensive rehabilitation program. It combines the best elements of various techniques and methods, and has a sound rationale based on exercise physiology. CONCLUSION: This protocol anticipates results obtained only with long periods of conventional physical therapy.

Falls and fall-related injuries are significant public health problems in older adults. While balance-controlling strategies have been extensively researched, there is still a lack of understanding regarding how fast the lower-limb muscles contract and coordinate in response to a sudden loss of standing balance. Therefore, this pilot study aims to investigate the speed and timing patterns of multiple joint/muscles’ activities among the different challenges in standing balance. Twelve healthy young subjects were recruited, and they received unexpected translational balance perturbations with randomized intensities and directions. Electromyographical (EMG) and mechanomyographical (MMG) signals of eight dominant-leg’s muscles, dominant-leg’s three-dimensional (3D) hip/knee/ankle joint angles, and 3D postural sways were concurrently collected. Two-way ANOVAs were used to examine the difference in timing and speed of the collected signals among muscles/joint motions and among perturbation intensities. This study has found that (1) agonist muscles resisting the induced postural sway tended to activate more rapidly than the antagonist muscles, and ankle muscles contributed the most with the fastest rate of response; (2) voluntary corrective lower-limb joint motions and postural sways could occur as early as the perturbation-induced passive ones; (3) muscles reacted more rapidly under a larger perturbation intensity, while the joint motions or postural sways did not. These findings expand the current knowledge on standing-balance-controlling mechanisms and may potentially provide more insights for developing future fall-prevention strategies in daily life.

Several pathologies can cause muscle spasticity. Modified Ashworth scale (MAS) can rank spasticity, however its results depend on the physician subjective evaluation. This study aims to show a new approach to spasticity assessment by means of MMG analysis of hamstrings antagonist muscle group (quadriceps muscle). Four subjects participated in the study, divided into two groups regarding MAS (MAS0 and MAS1). MMG sensors were positioned over the muscle belly of rectus femoris (RF), vastus lateralis (VL) and vastus medialis (VM) muscles. The range of movement was acquired with an electrogoniometer placed laterally to the knee. The system was based on a LabVIEW acquisition program and the MMG sensors were built with triaxial accelerometers. The subjects were submitted to stretching reflexes and the integral of the MMG (MMG _INT ) signal was calculated to analysis. The results showed that the MMG _INT was greater to MAS1 than to MAS0 [muscle RF (p= 0.004), VL (p= 0.001) and VM (p= 0.007)]. The results showed that MMG was viable to detect a muscular tonus increase in antagonist muscular group (quadriceps femoris) of spinal cord injured volunteers.