1000 resultados para Periodicos


Relevância:

10.00% 10.00%

Publicador:

Resumo:

The effects of vibration on the human body have been documented for many years. Recently, the use of vibration is an auxiliary method of physical training in the young, elderly and athletes. Recent studies indicate an increase in gain of strength, flexibility, endurance and power of individuals trained with vibrating equipments. Despite the fairly widespread use, the physiological effects of vibration are still poorly understood, and there is great variability in the training protocols used in the literature. Future studies should be conducted as a way to better understand the physiological effects of vibration and also the affects of different protocols on physical training as strength, flexibility, endurance and power.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A set of constraints on the performance of motor skills is a determinant factor of success in many sport modalities that require from the athlete continuous adaptation to changes in the game context. Taking into account Newell's model of organism (or performer), task and environmental constraints in the acquisition of motor skills (NEWELL, 1986), the focus of this study is the set of changes that take place in motor behavior from the beginner to the high level athlete. In specific, the focus is toward changes in sports settings in which the ball is the center of the game, responsible for the relationship among athletes of the same team as well as between opponents, as in volleyball. The ball, in its trajectory, carries on a set of constraints to the player's behavior. To be able of imposing constraints on the opponent's behavior is so important as to know how to deal with a ball sent to you by the opponent in an unpredictable trajectory.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Since the sport of football field as the main focus and it is directly related to sports phenomenon up to understood of changes occurring in the rules and game systems over the years. The main aim was analyzed the historical changes in the soccer with relation to the game systems and rules, and their consequences. The research is qualitative type and uses the bibliographic collection as instrument. For this, it was searched in the published literature data about the present study subject. The results indicated for a soccer tactics and rules set that it was constructed with the evolution and consolidation of the soccer. It was concluded that the game system had suffered many alterations during the historical process of soccer development, but this process leaved poured the spectacle of the game. In the other way, the rules had suffered great alterations with regard to the soccer primaries, but after its consolidation as universal sport, they had remained almost the same, having assisted in the maintenance of the soccer characteristics and status.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The aim was to analyze the prevalence of the stages of behavior change (BCS) and the perceived barriers to physical activity in older people residents in a medium size city of São Paulo state, Brazil. Seventy-nine older people participated of the study. The BCS was assessed by the Questionnaire of Behavior Chance Stages and those on perception of barriers by the Questionnaire on Barriers to the Practice of Physical Activity in Older People (QBPPAE). Statistical analyses was comprised by the Chi-square test (p<0.05). Data showed that: a) 64,6% of the older people do not practice physical activity and only 22,8% of them have been practicing it on a regular basis for more than 6 months; b) The most perceived barriers were: "Active enough", "Too old"; "Need to rest" and; "Disease or injury"; c) The BCS seems modulate significantly the perception of barriers (p<0.05). We can conclude that: a) most of the older people are in the pre-contemplation, contemplation and preparation stages of the BCS, yet; b) gender influences almost nothing with perception of barriers and; c) the BCS interferes with the type of perceived barriers. Such conclusions support the suggestions that it is necessary to develop specific strategies for different stages of behavior change if it is to minimize the barriers. This may help to find the most effective way to change to more active lifestyle in the elderly.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

This study examined the influence of both optic flow characteristics and intention on postural control responses. Two groups of 10 adults each were exposed to the room's movement either at 0.6 cm/s (low velocity group) or 1.0 cm/s (high velocity group). All the participants stood in the upright stance inside of a moving room and were informed about the room movement only after the fourth trial as they were asked to resist to its influence. Results revealed that participants from both groups were influenced by the imposed visual stimulus in the first trials, but the coupling strength was weaker for the high velocity group. The request to resist the visual influences decreased visual influences oil body sway, but only for the low velocity group. These results indicate that intention might play a role in stimulus influences on body sway but it is stimulus dependent.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Crossing moving obstacles requires different space-time adjustments compared with stationary obstacles. Our aim was to investigate gait spatial and temporal parameters in the approach and crossing phases of a moving obstacle. We hypothesized that obstacle speed affects gait parameters, which allow us to distinguish locomotor strategies. Ten young adults walked and stepped over an obstacle that crossed their way perpendicularly, under three obstacle conditions: control-stationary obstacle, slow (1.07 m/s) and fast speed (1.71 m/s) moving obstacles. Gait parameters were different between obstacle conditions, especially on the slow speed. In the fast condition, the participants adopted predictive strategies during the approach and crossing phases. In the slow condition, they used an anticipatory strategy in both phases. We conclude that obstacle speed affects the locomotor behavior and strategies were distinct in the obstacle avoidance phases.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Locomotion generates a visual movement pattern characterized as optic flow. To explore how the locomotor adjustments are affected by this pattern, an experimental paradigm was developed to eliminate optic flow during obstacle avoidance. The aim was to investigate the contribution of optic flow in obstacle avoidance by using a stroboscopic lamp. Ten young adults walked on an 8m pathway and stepped over obstacles at two heights. Visual sampling was determined by a stroboscopic lamp (static and dynamic visual sampling). Three-dimensional kinematics data showed that the visual information about self-motion provided by the optic flow was crucial for estimating the distance from and the height of the obstacle. Participants presented conservative behavior for obstacle avoidance under experimental visual sampling conditions, which suggests that optic flow favors the coupling of vision to adaptive behavior for obstacle avoidance.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Morphological caste differences and ovary conditions were analyzed in colony of Brachygastra lecheguana. The results indicate the presence of individuals with ovary development but uninseminated (intermediates). In addition, these females were similar in morphology to workers, suggesting that, in this case, intermediates are ovary-developed workers. Queens were morphologically larger than workers and intermediates in some characters and smaller in others. Multivariate analysis showed that queens were highly distinct. These results indicate that castes are pre-imaginally determined in B. lecheguana.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Determinations of Al and Mn concentrations in the tissues (gills, hepatopancreas and muscle) of the freshwater crab Trichodactylus fluviatilis and water samples, both collected from sites on tributaries of the Corumbatai River (São Paulo, Brazil) were performed. The Bioaccumulation Factor (BAF), calculated for different sites with respect to the water concentration, ranged from 173-555 for Al and from 636 - 921 for Mn. Dissolved concentrations of Al and Mn in water samples (collected in different sites) were related to the accumulation of these metals in crabs, suggesting that T. fluviatilis is good biomonitor for Al and Mn pollution in aquatic ecosystem.