Body mass index, perceived and actual physical competence: the relationship among young children.

BACKGROUND: The purpose of this study was to examine the relationship between perceived physical competence (PPC), actual motor competence (MC) and body mass index (BMI) in young children. METHODS: We assessed MC (Test of Gross Motor Development - 2nd Edition), PPC (Pictorial Scale of Perceived Competence and Social Acceptance) and BMI (CDC calculator) of 178 young children ages 4-7 years. RESULTS: The linear regression model for the overall sample showed that BMI was a better predictor of PPC than MC. Also, obese children had lower PPC, but showed no differences in MC compared with leaner peers. CONCLUSIONS: PPC of young obese children was lower than their leaner counterparts, yet their MC was similar. That outcome draws attention to the importance of promoting positive PPC in young children.

Postural control of small for gestational age infants born at term

OBJECTIVE: This study compared the postural control of small (SGA) and appropriate (AGA) for gestational age infants born at term, at the ages of 3, 6, 9 and 12 months. METHOD: This was a cohort study of infants born at term, with birth weight less than the 10th percentile for the SGA group and between the 10th and 90th percentiles for the AGA group. Infants with genetic syndromes, malformations, congenital infections and internment in neonatal intensive care unit were excluded. The evaluation instrument was the Alberta Infant Motor Scale. RESULTS: Comparison of the SGA and AGA groups did not show any significant differences (p>0.05) at the assessment times. However, the postural control of the SGA group was influenced by the gestational age (r=-0.83; p= 0.006) and 5th minute Apgar (r= 0.79; p= 0.01) in the 3rd month, and by maternal occupation (r= 0.67; p= 0.01) in the 6th month. CONCLUSION: It was concluded that the postural control was similar in the groups. However, the postural control of the SGA group was influenced by biological and environmental factors.

OBJETIVO: Este estudo teve por objetivo comparar o controle postural de lactentes nascidos a termo, pequenos (PIG) e adequados para a idade gestacional (AIG) nos 3º, 6º, 9º e 12º meses. MÉTODO: Estudo longitudinal de lactentes nascidos a termo, com peso de nascimento menor que o percentil 10 para o grupo PIG e entre o percentil 10 e 90 para o grupo AIG. Síndromes genéticas, más-formações, infecções congênitas e internados em unidade de terapia intensiva neonatal foram excluídos. O instrumento de avaliação foi Alberta Infant Motor Scale. RESULTADOS: A comparação do grupo PIG e AIG não mostrou diferença significativa (p> 0,05) nos meses avaliados. Entretanto, o controle postural do grupo PIG foi influenciado pela idade gestacional (r= -0,83/p= 0,006) e Apgar de 5' (r= 0,79/p= 0,01) no 3º mês; e pela ocupação materna (r= 0,67/p= 0,01) no 6º mês. CONCLUSÃO: Concluiu-se que o controle postural foi similar nos grupos; porém o controle postural do grupo PIG foi influenciado por fatores biológicos e ambientais.

Imagined and actual limb selection: a test of preference.

Imagined and actual motor performance were compared to determine what factor(s) drive limb selection for programming movements in contralateral hemispace. Forty right-handed blindfolded subjects were asked to 'reach' via auditory stimulus for a small object placed at multiple locations in hemispace. Two conditions were included: arms uncrossed and arms crossed. With the uncrossed condition, responses were similar. With arms crossed, subjects had the choice of keeping the limbs crossed, reacting to proximity, or uncrossing the arms to reach ipsilaterally. In this condition subjects 'imagined' that they would maintain the crossedposition and reach with the hand closest to the stimulus in both right and left hemispace. However, during 'actual' reaching, responses differed. For left-field stimuli, participants kept the arms crossed, but in response to right-field stimuli, subjects preferred to uncross the limbs in order to reach with the dominant hand. These findings suggest that while motor dominance is the primary factor in limb choice for action in ipsilateral hemispace, it appears that object proximity drives limb selection for reaching in contralateral hemispace.

Motor development during the first year: a comparative study.

This investigation of the motor development characteristics of Brazilian infants during the 1st year of postnatal life compared the findings with those of a widely used U.S. sample (N. Bayley, 1993). Analysis of the 12 monthly assessments indicated that Brazilian infants' scores increased with age, with the greatest increase occurring over the first 8 months. As a general comparison, the results are similar to the U.S. patterns of development. However, the Brazilian sample exhibited mean scores significantly lower than the U.S. sample's in the 3rd, 4th, and 5th months. More specific analyses indicated that the difference within these months was on tasks of sitting and grasping. Possible explanations for the differences focus on variations in child-rearing practices and the influence of biological maturation in early movement behaviors.

Lateralized effects on reaching by children.

This study examined the limb selection profiles of children for a reach-to-grasp task presented in various positions of hemispace. Underlying questions focused on the use of attentional information and lateralized effects in motor programming for reaching movements. As expected, both right- and left-handed groups used their dominant limb more frequently at the midline and in their own ipsilateral hemispace. However, in response to stimuli presented in contralateral (to the dominant limb) hemispace, both groups switched to using their nondominant limbs at significant levels. As a general comparison, right-handers exhibited greater use of their dominant limb, but arguably, motor dominance in this context may have intervened with the participant's ability to use attentional information to produce a more efficient response. Overall, these findings address the phenomenon associated with motor dominance and use of attentional information in programming.

The need for quality physical education.

Recently, the U.S. Surgeon General described two aspects of national health that require our immediate attention: As a nation, we are becoming increasingly more sedentary and more overweight. Furthermore, he and some of the most prominent health agencies have suggested that one of the primary strategies to overcome what is viewed as a national epidemic is the promotion of quality physical education in our schools. This paper describes in brief the facts associated with this concern, what is meant by quality physical education, and the role of the school nurse in helping to promote physical education in the schools.

What determines choice of limb for unimanual reaching movements?

Currently, relatively little is known about what drives the choice of limb for goal-oriented reaching. Traditionally, the explanation has been tied predominately to motor dominance as manifested in handedness. This article offers data and an argument suggesting that handedness can be modified by attentional (spatial) information. Although motor dominance may be the controlling factor in the programming and execution of reaching movements at the midline and hemispace ipsilateral (same side) to the dominant limb, attentional information alters the programming of movements in what would be contralateral space. The general trend of behavior is characterized by reaching on the same side as the stimulus, in ipsilateral fashion, a phenomenon explained by kinesthetic efficiency and hemispheric bias.

Foot preference changes through adulthood.

Developmental observations in foot laterality suggest increasing right-footedness from early childhood to young adult years, with few reports on behaviour beyond this time frame. This investigation confirmed recent suggestions by Porac (1996) of a continuation of this trend into middle and older adulthood, along with significant decreases in mixed-and left-foot preferences. Trends towards increasing right-footedness are linked to hemispheric heterochrony (right hemisphere ageing) and the right-sided world phenomenon.

Attentional effects on reaching in hemispace.

Previous evidence notes that attentional information in the form of visually guided stimuli can override motor dominance when programming reaching-to-grasp movements in contralateral hemispace. The present experiment verified these effects for 135 university students, using an auditory stimulus, and the pattern of behavior in the two modalities was quite similar.

Examining the mobilizing feature of footedness.

This study examined the mobilizing feature of footedness in a unilateral and a bilateral context. Analysis for 47 right- and 32 left-footed undergraduates indicated a strong relationship between preferred limbs in both conditions, with right footer showing the strongest concordance. Theoretical explanations for the origin of behavior and differences in right versus left concordance are discussed. Based on selected previous reports and present findings, it seems reasonable that for most persons the right foot may be preferred for mobilizing activities regardless of behavioral context.

Considering handedness in studies involving manual control.

With studies of motor behavior that feature manual control, it is suggested that the methodology used to select subjects in reference to handedness be reviewed. This suggestion is in view of the recommendation that simply asking subjects to identify their writing hand is inadequate to define handedness. Complementing this are recent findings in neuroscience indicating differences, at times significant, in information-processing behavior based on handedness classification. A brief review of recently published studies in two prominent outlets for motor behavior research confirms that most reports provide minimal (and sometimes no) information regarding handedness and the method used for assessment. Recommendations for addressing the problem include using an acceptable preference inventory, selecting only those subjects with strong lateral characteristics, and briefly describing the methodology used for the reviewing audience.

Attentional stimuli and programming hand selection: a developmental perspective.

This experiment examined the use of attentional stimuli for reaching in hemispace by strong right-dominant adults and children. Driving the hypothesis was the notion that developmental factors associated with use of attentional information may affect the programming of reaching movements in hemispace. Although the general pattern of responses was similar for both samples, children did not use attentional cues to program reaching movements in contralateral hemispace as effectively as adults. This result suggests that motor dominance and perhaps other factors were pivotal in motor programming for children. One possible explanation for the general behavior observed underlies an attentional hemispheric bias for a tendency to use the hand that is on the same side as the stimulus.

A lateralized comparison of handedness and object proximity.

This study was motivated by the emerging hypothesis that right-handers are more strongly lateralized and perform better on various aspects of functional asymmetry than do left-handers. Right- and left-handers were observed for hand selection responses to a unimanual task of reaching for a small cube in positions of right- and left hemispace, prompting hemispheric decision-making related to hand dominance and attentional (visuospatial) stimuli. As predicted, left-handers did not respond with their preferred limb as consistently across positions as did right-handers. Additional inspection of the task suggests that being lateralized may not be a disadvantage in this context, and that environmental influence may play a significant role in hand selection for a particular motor event.

Examining the stabilising characteristics of footedness.

The stabilising characteristics of footedness within the contexts of unilateral and bilateral preference and performance were examined. Predictions from Previc's (1991) theory of prenatal determination of functional asymmetry suggest a reliance on the left side of the body for stabilisation regardless of context. To test the hypothesis, right- and left-footers (as assessed bilaterally) were examined for preference and performance using a one-leg static balance task on a force plate in simple and complex conditions. Results indicated that preference for stabilisation in the bilateral context was independent of limb choice in the unilateral context. That is, the majority of individuals switched limbs for stabilisation in the unilateral context (most favoured the right side). These findings lead to the conclusion that foot preference may be dependent in part on the context of the task and not bound exclusively to neurodevelopmental origins.

Brief communication: bilateral footedness and task complexity.

The primary intent of this investigation was to determine if stabilizing complexity (postural control) influenced lower limb selection while performing a bilateral footedness task. Right- and left-footed subjects (as determined by a bilateral preference inventory) were asked to stand on one foot and tap a telegraph key with the opposite foot repeatedly. The bilateral task was conducted in two conditions of stabilizing complexity, with the intent to augment focus of attention between stabilizing and mobilizing limb: simple (lights on) and complex (limitation of visual cues). Results indicated that in both simple and complex conditions, 50% or more of subjects switched stabilizing limbs or showed no preference when comparing preference inventory behavior to experimental conditions, suggesting, in general, that foot preference may be in part dependent on the context of the task and not tied predominantly to biological theory.

A question of foot dominance.

It is suggested that the popular definition of foot dominance (i.e., the limb preferred to execute a manipulative or mobilizing action while the other [nondominant] foot provides stabilizing support, e.g., kicking a ball) be reconsidered in light of understanding the functional characteristics of footedness and selected theoretical explanations. Relevance to future research designs and assessment methodology is discussed.

Laterality patterns and visual-motor coordination of children.

This study examined the association between laterality patterns of eye-hand and eye-foot described as congruent or cross-lateral, and visual-motor coordination skill (target throwing and kicking) by 606 4- to 6-yr.-olds. Speculation derived from contemporary reports of hand preference and motor coordination provided the hypothesis that persons exhibiting congruent patterns of eye and limb laterality such as right-eye and hand or right-eye and foot pattern would perform better than peers who exhibited other laterality patterns. To the contrary, this study yielded no significant differences in motor performance between groups with different patterns of preference. In view of past studies and present results, additional inquiry seems warranted before any consensus regarding the association between laterality and motor coordination can be established.

Foot laterality in children, adolescents, and adults.

This investigation reviewed 14 studies describing the trichotomous distribution of foot preference behaviour spanning early childhood to adult years. Findings suggest that a substantially greater percentage of children are mixed-footed in comparison to older individuals. A significant shift towards right-sidedness appears to occur sometime during late childhood, after which, behaviour remains relatively stable. The incidence of left-footedness is similar across the lifespan. In comparison to handedness, substantially more (about twice as many) young children are mixed-footed compared to mixed-handed. A similar pattern is noted during adolescence and adulthood, but the differences are smaller. Values for leftsidedness (upper and lower limbs) are comparable across the lifespan. Of the existing theoretical models, Annett's Right-shift hypothesis with additional propositions related to environmental influences (Collins, 1977; Porac, 1993; Provins, 1992) provides partial explanation for the findings.

Lower-limb speed and foot preference in children.

Foot preference and performance characteristics of gross-motor lower-limb speed of tapping were examined in 606 4- to 6-yr.-olds. Analysis indicated no effect for gender; however, speed of foot tapping increased significantly across the three ages, suggesting an association with selected developmental (neuromuscular) processes. Contrary to earlier reports on handedness, there was no statistical evidence that mixed- or left-footers were at a performance disadvantage compared to right-footers. All groups performed best with the right foot, limb differentiation (right versus left) being significant for the right- and mixed-footed groups. Speculation about maturational and environmental influences is given.