An adaptive process model of motor learning: insights for the teaching of motor skills

This article presents an outline of a non-equilibrium model, in which motor learning is explained as a continuous process of stabilization and adaptation. The article also shows how propositions derived from this model have been tested, and discusses possible practical implications of some supporting evidence to the teaching of motor skills. The stabilization refers to a process of functional stabilization that is achieved through negative feedback mechanisms. Initially, inconsistent and incorrect responses are gradually reduced, leading to a spatial-temporal patterning of the action. The adaptation is one in which new skills are formed from the reorganization of those already acquired through the flexibility of the system, reorganization of the skill structure, or self-organization. In order to provide learners with competency for adaptation, teachers should (a) guide students to learn motor skills taking into account that the stabilization of performance is just a transitory state that must be dismantled to achieve higher levels of complexity; (b) be clear which parts (micro) compose the skills and how they interact in order to form the whole (macro); (c) manipulate the skills in terms of their temporal, spatial, and/or spatiotemporal dimensions; (d) organize practice initially in a constant way, and then in a varied regimen (random) when the motor skills involve requirements of time and force; and, inversely for motor skills with spatial demands; and (e), provide a moderate frequency of feedback.

Professional preparation in physical education: changing labor market and competence

Professional preparation is indeed a complex and dynamic process because it involves a number of interacting elements, which change in time. The objective of the present essay is to analyze the professional preparation in physical education, with the focus on the relation between the very dynamic labor market and the required competence of the professionals to deal with the associated demands. There is no doubt that the professional preparation must not aim to train professionals to merely repeat means for solving practical problems, but professionals with the capacity to repeat the process of solving problems. Consequently, professional preparation programs need to be formative instead of informative and prepare professionals capable of using scientific thinking and method to solve practical problems of intervention.

Prior knowledge of final testing improves sensorimotor learning through self-scheduled practice

The elaboration of learning strategies has been considered a key factor to explain sensorimotor learning gains obtained in self-scheduled practice conditions. Nevertheless, the effect of prior knowledge of the testing context (i.e., the learning goal) on that process has been neglected. This study sought to determine whether: (a) learners in a self-controlled condition make different choices contingent on having or not having a learning goal; (b) providing a learning goal would modify the effects of a self-controlled practice condition, and (c) the effect of providing a learning goal would be due to the augmented cognitive effort or to the practice schedule resulting from the learning strategies. The results show that prior knowledge of a variable testing context affects the elaboration of learning strategies and improves skill acquisition in a self-scheduled practice condition. Furthermore, learning gains can be attributed to the self-imposed practice schedule resulting from the learning strategies, and not to the process of elaborating them.

Genetic and environmental influences on blood pressure and physical activity: a study of nuclear families from Muzambinho, Brazil

Blood pressure (BP) and physical activity (PA) levels are inversely associated. Since genetic factors account for the observed variation in each of these traits, it is possible that part of their association may be related to common genetic and/or environmental influences. Thus, this study was designed to estimate the genetic and environmental correlations of BP and PA phenotypes in nuclear families from Muzambinho, Brazil. Families including 236 offspring (6 to 24 years) and their 82 fathers and 122 mothers (24 to 65 years) were evaluated. BP was measured, and total PA (TPA) was assessed by an interview (commuting, occupational, leisure time, and school time PA). Quantitative genetic modeling was used to estimate maximal heritability (h²), and genetic and environmental correlations. Heritability was significant for all phenotypes (systolic BP: h² = 0.37 ± 0.10, P < 0.05; diastolic BP: h² = 0.39 ± 0.09, P < 0.05; TPA: h² = 0.24 ± 0.09, P < 0.05). Significant genetic (r g) and environmental (r e) correlations were detected between systolic and diastolic BP (r g = 0.67 ± 0.12 and r e = 0.48 ± 0.08, P < 0.05). Genetic correlations between BP and TPA were not significant, while a tendency to an environmental cross-trait correlation was found between diastolic BP and TPA (r e = -0.18 ± 0.09, P = 0.057). In conclusion, BP and PA are under genetic influences. Systolic and diastolic BP share common genes and environmental influences. Diastolic BP and TPA are probably under similar environmental influences.

Efeitos da informação comportamental na dinâmica intrínseca do controle postural

Esse estudo teve como objetivo examinar possíveis alterações na dinâmica intrínseca de crianças e adultos decorrentes de informações externas na realização de uma tarefa de manutenção da postura ereta. Participaram do estudo dez crianças de 8 anos de idade e dez adultos jovens de ambos os gêneros. Eles permaneceram na posição ereta dentro de uma sala móvel que foi movimentada continuamente para frente e para trás. Os participantes recebiam informação sobre o movimento da sala e eram solicitados a não oscilar ou a oscilar junto com o movimento da mesma. Os resultados mostraram que a manipulação da informação visual induziu oscilação corporal correspondente (dinâmica intrínseca) em crianças e adultos. Informação sobre o movimento da sala e solicitação de uma ação (informação comportamental) alteraram o relacionamento entre informação visual e oscilação corporal. Crianças apresentaram mais dificuldades em alterar a dinâmica intrínseca do que adultos, indicando que elas são mais dependentes da dinâmica intrínseca do que adultos. Esses resultados trazem implicações importantes para a situação de ensino-aprendizagem, pois indica que aprendizagem envolvendo crianças deve ser estruturada propiciando condições mais favoráveis para alterações na dinâmica intrínseca para que os objetivos da mesma sejam alcançados.

Effects of temporal stimuli in the acquisition of a serial tracking task

This study investigated the effects of temporal stimuli on qualitative responses during the acquisition of a serial tracking task. One hundred and twenty young adult men performed 100 trials of a tracking task that consisted of touching six response keys in a given sequence in response to flashing light-emitting diodes in order to identify and learn the serial pattern. Six experimental groups were created with diverse inter stimuli intervals (ISI): G1: ISI = 300 ms; G2: ISI = 400 ms; G3: ISI = 500 ms; G4: ISI = 600 ms; G5: ISI = 700 ms; and G6: ISI = 800 ms. Performance was assessed by means of four types of responses: omission, error, correct, and anticipatory responses. The results showed differential effects of temporal stimulus uncertainty in the hierarchy of responses as the learning course progressed.

The game of futsal as an adaptive process

Some researchers have described team sports as complex, open, and hierarchical systems. This study aimed to investigate and describe how the game of futsal could be characterized as a dynamic adaptive process. One game, which included participation by two amateur teams, was analyzed by examining players' individual (space occupied, skills with and without ball) and collective actions (attacks and defenses). Data were collected through time-continuum notation, and were analyzed through frequencies and clustering, using trend analysis and multiple comparisons, and Ward's minimum variance method with Euclidean distance, respectively. Results revealed four attack patterns for each team, with four defense patterns for one (Blue), and seven for the other (Red), and they showed within-pattern variability. All were performed in an unpredictable manner, with no absolute correspondence between attacks and defenses. The futsal game as an adaptive process was characterized by changing intra- and inter-patterns.

Risco cardiovascular e prática de atividade física em crianças e adolescentes de Muzambinho/MG: influência do gênero e da idade

INTRODUÇÃO E OBJETIVO: A doença cardiovascular inicia na infância e está atrelada à presença de fatores de risco cardiovascular (FRC). A prevalência desses fatores varia em diferentes populações brasileiras, tendo sido estudada principalmente em cidades de médio e grande porte. Este estudo avaliou a prevalência dos FRC e da prática de atividade física (AF) em crianças e adolescentes de Muzambinho, uma cidade de pequeno porte. MÉTODO: Foram avaliados 205 sujeitos (entre sete e 18 anos - 108 do gênero masculino). Foram medidos: peso, estatura, glicemia, colesterolemia, pressão arterial (PA) e prática de AF. As comparações foram realizadas pelo teste do Qui-quadrado. RESULTADOS: A prevalência de sobrepeso foi de 19% e de valores alterados de PA, glicemia e colesterolemia foram de, respectivamente, 11, 5 e 15%. Não houve diferença na prevalência dos FRC entre os sexos. O tabagismo, o alcoolismo, a PA alterada e a insuficiência de AF aumentaram com a idade. Setenta e nove por cento dos sujeitos praticavam AF de locomoção, 10% ocupacional, 97% nas aulas de educação física, 72% no recreio e 90% de lazer. Noventa e dois por cento foram considerados ativos. A prática de AF ocupacional foi maior nas meninas e aumentou nos meninos com a idade. A prevalência de AF de lazer e recreio diminuiu com a idade nos dois sexos. CONCLUSÃO: A prevalência de FRC, exceto do sedentarismo, foi expressiva, não diferiu entre os sexos e aumentou com a idade. A prática de AF de todos os tipos foi alta, diferenciou-se entre os sexos e diminuiu com a idade.

Number of options in a movement sequence affects learners' behavior in a self-controlled practice condition

Self-controlling practice implies a process of decision making, which suggests that the options in a self-controlled practice condition could affect learners. The number of task components with no fixed position in a movement sequence may affect the way learners self-control their practice. A 200-cm coincident timing track with 90 light-emitting diodes (LEDs)--the first and the last LEDs being the warning and the target lights, respectively--was set so that the apparent speed of the light along the track was 1.33 m/sec. Participants were required to touch six sensors sequentially, the last one coincidently with the lighting of the target light (timing task). Group 1 (n = 55) had only one constraint, and were instructed to touch the sensors in any order, except for the last sensor which had to be the one positioned close to the target light. Group 2 (n = 53) had three constraints: the first two and the last sensor to be touched. Both groups practiced the task until timing error was less than 30 msec. on three consecutive trials. There were no statistically significant differences between groups in the number of trials needed to reach the performance criterion, but (a) participants in Group 2 created fewer sequences compared to Group 1, and (b) were more likely to use the same sequence throughout the learning process. The number of options for a movement sequence affected the way learners self-controlled their practice, but had no effect on the amount of practice to reach criterion performance.

Postoperative chylothorax in congenital diaphragmatic hernia

INTRODUCTION

The mechanisms responsible for postoperative chylothorax in Congenital Diaphragmatic Hernia (CDH) patients remain unclear. The aim of the present study was to examine the clinical features of CDH that may contribute to an association with postoperative chylothorax.

MATERIAL AND METHODS

198 neonates with CDH, in whom surgical repair of a diaphragmatic defect was performed between 1981 and 2008, were retrospectively studied. The patients were divided into 2 groups; patients with postoperative chylothorax (group I, n=11) and patients without postoperative chylothorax (group II, n=187). The clinical findings were compared between group I and group II to investigate potential predictive parameters for an association with chylothorax. Moreover, the clinical findings and treatments were evaluated in patients with chylothorax.

RESULTS

11 of the 198 infants (5.5%) developed a chylothorax. Although the incidence of a prenatal diagnosis was slightly higher in group I, no relationship with other clinical features was found which would indicate the severity of CDH or the occurrence of postoperative chylothorax. Treatment for chylothorax was drainage alone in 2 cases, total parenteral nutrition with drainage in 8 infants and additional intrathoracic OK-432 infusion in 1 patient. No patients required surgical intervention for chylothorax. No recurrences were observed in this patient series.

CONCLUSIONS

It was concluded that postoperative chylothorax is not rare in infants after CDH repair. However, no statistically significant predictive parameters for chylothorax were identified, except for the presence of a prenatal diagnosis.

Constant-random practice and the adaptive process in motor learning with varying amounts of constant practice

The adaptive process in motor learning was examined in terms of effects of varying amounts of constant practice performed before random practice. Participants pressed five response keys sequentially, the last one coincident with the lighting of a final visual stimulus provided by a complex coincident timing apparatus. Different visual stimulus speeds were used during the random practice. 33 children (M age=11.6 yr.) were randomly assigned to one of three experimental groups: constant-random, constant-random 33%, and constant-random 66%. The constant-random group practiced constantly until they reached a criterion of performance stabilization--three consecutive trials within 50 msec. of error. The other two groups had additional constant practice of 33 and 66%, respectively, of the number of trials needed to achieve the stabilization criterion. All three groups performed 36 trials under random practice; in the adaptation phase, they practiced at a different visual stimulus speed adopted in the stabilization phase. Global performance measures were absolute, constant, and variable errors, and movement pattern was analyzed by relative timing and overall movement time. There was no group difference in relation to global performance measures and overall movement time. However, differences between the groups were observed on movement pattern, since constant-random 66% group changed its relative timing performance in the adaptation phase.

Prenatal diagnosis and outcome of partial agenesis and hypoplasia of the corpus callosum

OBJECTIVE

To present antenatal sonographic findings and outcome of fetuses with hypoplasia or partial agenesis of the corpus callosum.

METHODS

The database of our ultrasound laboratory was searched retrospectively for cases of hypoplasia or partial agenesis of the corpus callosum suspected at antenatal neurosonography between 1998 and 2008 and confirmed by pathology or postnatal neuroimaging. In surviving infants, clinical follow-up had been arranged to assess neurodevelopmental outcome.

RESULTS

Nineteen fetuses with callosal underdevelopment were identified at a median gestational age of 22 (range, 21-33) weeks and confirmed at follow-up, including 14 with partial agenesis and five with hypoplasia. Among the 14 fetuses with partial agenesis, there were additional brain findings in 10, including two with absent cavum septi pellucidi, four with mild isolated ventriculomegaly and four with cerebellar abnormalities, two of which also had ventriculomegaly. Pregnancy was terminated electively in seven of the cases with partial agenesis and there was one neonatal death. Among the six surviving infants, neurodevelopmental outcome was appropriate for age in three at follow up, including two cases with isolated partial agenesis of the corpus callosum. Among the five fetuses with prenatally diagnosed callosal hypoplasia, additional anomalies were present in four. Two cases were terminated electively and three were alive at the time of writing, with a median age of 3 years. Among them, apparently normal neurological development was observed in only one case.

CONCLUSIONS

An antenatal diagnosis of callosal underdevelopment is possible by expert sonography. There is often association with other major anomalies. However, even in fetuses with apparently isolated findings, the prognosis is uncertain.

Frey procedure for chronic pancreatitis in a child with duodenal atresia and complex pancreaticobiliary disorders

A boy aged 2 years and 7 months who had undergone duodeno-duodenostomy for duodenal atresia and annular pancreas in the neonatal period presented with recurrent pancreatitis. ERCP showed an incomplete pancreas divisum associated with pancreaticobiliary maljunction. At 3 years and 8 months of age, we performed a Frey procedure in combination with total excision of the extrahepatic bile duct. The main pancreatic duct was opened in the body and the head was cored out anteriorly. The pancreaticobiliary system was reconstructed with a Roux-en-Y anastomosis. The patient has been free from symptoms with excellent weight gain in the follow-up period of 20 months. The Frey procedure can be a safe and effective operation in children with chronic pancreatitis caused by complex pancreatobiliary disorders associated with duodenal atresia.

Relative Frequency of Knowledge of Results and Task Complexity in the Motor Skill Acquisition

The aim of this study was to investigate the effects of knowledge of results (KR) frequency and task complexity on motor skill acquisition. The task consisted of throwing a bocha ball to place it as close as possible to the target ball. 120 students ages 11 to 13 years were assigned to one of eight experimental groups according to knowledge of results frequency (25, 50, 75, and 100%) and task complexity (simple and complex). Subjects performed 90 trials in the acquisition phase and 10 trials in the transfer test. The results showed that knowledge of results given at a frequency of 25% resulted in an inferior absolute error than 50% and inferior variable error than 50, 75, and 100% frequencies, but no effect of task complexity was found.

Congenital colonic stenosis: a case of late-onset

PURPOSE

Colonic atresia and stenosis are rare causes of intestinal obstruction in the infant. Only 1.8%-15% of intestinal atresias occur in the colon. Congenital colonic stenosis is even less common than colonic atresia. Only 10 cases have been reported in Literature since 1966 and only one late-onset case has been reported in Literature until now. We describe the case of a 4-month-old baby coming to our attention because of an intestinal subocclusion due to a congenital colonic stenosis of the ascending colon.

CASE REPORT

A 4-month-old baby came to our attention for persistent abdominal distension, reduction of bowl function and decaying of overall clinical conditions. A plain abdominal radiograph showed distended intestinal loops with air-fluid levels and no gas in the rectum. During the barium enema the contrast medium appeared to completely fill the lumen of the colon up to the ileo-cecal valve and Cecum appearing higher than normal. Beyond the ileo-cecal valve, the contrast medium showed an abnormal hypotonic dilatation of the small intestinal loops. Suspecting an organic intestinal obstruction, an explorative laparotomy was deemed necessary and at halfway in the ascending colon a stenosis was found.

RESULTS

The post-operative course was uneventful and the patient is currently in good clinical conditions, has a normal diet and is thriving.

CONCLUSION

Considering both the Literature and our own experience, it is wise to reckon the congenital colonic stenosis as a rare but possible cause of complete or partial intestinal obstruction not only in the newborn but also throughout the first year of life.

Technical variation in a sample of high level judo players

Technical actions performed by two groups of judokas who won medals at World Championships and Olympic Games during the period 1995-2001 were analyzed. In the Super Elite group (n = 17) were the best athletes in each weight category. The Elite group (n = 16) were medal winners who were not champions and did not win more than three medals. Super Elite judokas used a greater number of throwing techniques which resulted in scores, even when expressed relative to the total number of matches performed, and these techniques were applied in more directions than those of Elite judokas. Further, the number of different throwing techniques and the variability of directions in which techniques were applied were significantly correlated with number of wins and the number of points and ippon scored. Thus, a greater number of throwing techniques and use of directions for attack seem to be important in increasing unpredictability during judo matches.