M. Rajic's research while affiliated with Université du Québec à Trois-Rivières and other places

The purpose of this project was to undertake a long-term follow-up of participants in the Trois-Rivieres Growth and Development Study. Some 20 years after their initial involvement in the program, two groups were compared: experimental subjects (n = 150) who had received 5 one-hour sessions of specialized physical education per week throughout their 6 years of primary school, and the original control group (n = 103). All subjects completed a questionnaire regarding current patterns of physical activity (PA), attitudes and beliefs about PA, and perceived barriers to PA. Principal results indicate: (a) More experimental than control women exercise 3 times or more per week, (b) experimental subjects more commonly perceived their health to be very good to excellent, (c) control subjects in general felt less psychological dependency on exercise, and (d) women in the experimental group had a lower relative risk of back problems.

This case report examines whether there was any cross-contamination between students enrolled in classes that received additional physical education, and their siblings who were enrolled in preceding and succeeding class-cohorts. A controlled longitudinal study extending over 6 years of primary school. An urban and a rural primary school in Québec. 546 primary students, comprising approximately equal numbers of boys and girls from the urban and the rural school. Entire class-cohorts were given and hour of additional physical education ach day throughout their primary schooling, with immediately preceding and succeeding class-cohorts serving as controls. The measured data included standing height, body mass, maximal oxygen intake (direct treadmill test) and PWC170. We found no evidence of cross-contamination between siblings in experimental and control class-cohorts. Although a theoretical possibility, cross-contamination between students in preceding and succeeding class-cohorts does not seem an important source of error in primary school students, presumably because such children prefer to play with friends from their immediate age cohort.

The possible limitation that cohort effects could impose upon the interpretation of longitudinal research has been examined, taking data on the standing height and the maximal oxygen intake of 546 primary school students participating in the Trois Rivières mixed-longitudinal study of enhanced physical education programs (295 experimental and 251 control subjects of both sexes). Over the short period of the study (maximum intercohort time span of 4 years), no significant differences in standing height were observed. In the larger urban community of Trois Rivières (population about 100,000), where the program of additional physical education was very successful in augmenting the maximal oxygen intake of the experimental students, a statistically significant intercohort difference of aerobic power developed among control students over the span of 3–4 years. However, in Pont Rouge (population about 5,000), where the added physical education had a smaller impact upon the maximal oxygen intake of the experimental students, there were no significant intercohort differences. Among possible explanations of the intercohort difference seen in Trois Rivières, the most likely seems an indirect effect of the experimental physical education program upon the patterns of habitual physical activity in the control population. © 1993 Wiley-Liss, Inc.

The “unisex phantom” tactic of Ross and associates attempts to examine proportional growth, expressing body measurements relative to a phantom created from arbitrary mean dimensions and the observed coefficients of variation for an arbitrary sample of adult men and women. Fundamental assumptions of the model are (1) that data treated in unisex fashion have the normal distribution required of Z-type statistics throughout the period of growth, and (2) that it is reasonable to consider anthropometric measurements in all populations (regardless of ultimate size) as growing toward the common height chosen for the phantom. The validity and possible usefulness of this approach has been tested using anthropometric data collected on 546 francophone primary school children from the Trois Rivières district who had been measured repeatedly from 6 to 12 years of age. Over this age range, the mixing of data for girls and boys does not create a bimodal distribution, and has only a marginal effect upon skewing and kurtosis; however, the requirement of a normal distribution is not satisfied by quite a number of common anthropometric measurements even at this age. Moreover, application of the unisex phantom procedure to the Trois Rivières sample does little to clarify anticipated sex-related differences in regional growth, and it is argued that univariate standardization against a power function of an arbitrary adult height may not provide the best method of examining the multivariate problem of growth. Comparison of results with data from Saskatoon, previously treated by unisex phantom methodology, reveals puzzling inconsistencies; it is suggested that interlaboratory differences of methodology rather than ethnic differences are responsible for apparent discrepancies in growth patterns. It is urged that interlaboratory validation of techniques and landmarks should precede the ascription of apparent differences in body build to constitutional factors.

The present study examined the impact of sociocultural factors upon the body dimensions of primary school children (age 6-12 years) living within a uniquely francophone region of Québec. Data was collected prospectively on 546 students, drawn in approximately equal numbers from the two sexes and from urban and rural environments. Habitual activity was modified by allocating a half of the sample to an experimental programme that incorporated an additional five hours of required endurance activity per week into the primary school curriculum. Body dimensions at any given age were less in rural than in urban Québec, probably because of continuing socio-economic constraints. However, an increase of habitual physical activity did not modify body size. Stature was comparable with Demirjian 's Montr eal sample of francophone children, but was less than for anglophone children. Our within-sample variance suggests that socio-economic factors could explain only a part of the discrepancy. Relative to Toronto students, other dimensions such as height were affected less than standing height.

The subdiscipline of psychomotricity provides a useful link between the purely physical development of the child and the total process of education; in a free translation of Piaget (1956) “All cognitive mechanisms depend on movement. Beneath language, and conceptualisation, knowledge is first and foremost an action upon an object, and thus in its very roots it implies a permanent representation of movement at the highest levels of the brain.” The body schema forms the corner stone of both education and reeducation in the psychomotor domain. Again translating freely, Le Boulch (1966) considers this as “an organisation of sensations describing one’s own body relative to perceptions of the outside world.” Elements in the schema to be discussed include the correct perception of body dimensions, concepts of laterality and vertically, and finger recognition.

There have been many previous studies on the influence of sports participation upon academic achievement (Voile et al. 1982a). Nevertheless, opinion is still divided as to whether scholastic attainments are improved, worsened, or unchanged by an increase of physical activity during childhood. Possible reasons for the discrepant results include: (a) population differences with respect to age, mental development, and body image; (b) use of retrospective, cross-sectional analyses that have sought relationships between existing academic performance and physical variables; (c) comparisons between self-selected groups such as athletes and nonathletes; (d) ‘halo’ effects, as teachers and fellow students have rewarded popular competitors by both praise and higher marks; (e) gains of self-image resulting from such adulation but influencing academic performance; (f) loss of curricular time through extensive training and participation in athletic contests; and (g) review of the results of experimental programs after an undesirably short period of time.