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J Simons

Publications and source records attributed to J Simons.

81 records · Page 5Linked to original sources
PubMedDate not supplied

Chronological and biological age as related to physical fitness in boys 12 to 19 years.

The relative importance of skeletal age and chronological age in explaining body measurements and the relative importance of skeletal age, chronological age, height, weight, and their interactions in explaining motor fitness components are reported. Anthropometric, motor fitness, and skeletal maturity data have been collected in a mixed longitudinal study of Belgian school boys 12+/- - 19+/- years. At each age level multiple regression equations were calculated to evaluate the relative importance of the independent variables. Skeletal age was assessed by the TW2 method and the anthropometric measurements were taken following standard procedures. The motor fitness tests were selected on their factor loading and reliability in the same age range. Between 13 and 16 years a fairly high percentage of the variation in body dimensions is explained by skeletal age (+/-50% for stature). The percentage of explained variance reaches its maximum at 14-15 years. The highest percentage is found for linear dimensions and weight followed by bone width dimensions and circumferences. Triceps and calf skinfolds are not related to skeletal age. Chronological age as such does not contribute in the prediction of body measurements. The interaction between chronological age and skeletal age as such or in combination with height and/or weight have the highest predictive value except for trunk strength (leg lifting) and functional strength (bent arm hang). Except for static strength (arm pull), for which the explained variance ranged from 33% to 58%, the predictive value of body size, maturity, chronological age and their interactions is rather low, varying between 0% and 17%. As for body dimensions, the explained variance reaches its maximum for most motor tests at 14-15 years.

Adolescent↗
PubMedDate not supplied

Patterns of TW-1 and TW-2 skeletal age differences in 12-19-year-old Belgian boys.

The pattern of differences between TW-1 and TW-2 skeletal ages was investigated in a mixed longitudinal sample of Belgian school boys aged about 12-19 years. The differences between the TW-1 and TW-2 skeletal ages decrease from 12 years until 15 years, then increase until they stabilize at 17 years. TW-1 skeletal ages are greater than TW-2 skeletal ages, except at 14 and 15 years. This trend confirms the findings in better-off black and white Philadelphia children and in disadvantaged Mexican children (Malina and Little 1981).

Adolescent↗
PubMedDate not supplied

Stability of anthroposcopic and anthropometric estimates of physique in Belgian boys followed longitudinally from 13 to 18 years of age.

The stability of physique determined by the anthroposcopic 'Atlas' technique and the anthropometric Health-Carter method was examined in a sample of 210 healthy Belgian schoolboys studied longitudinally at yearly intervals from 13 to 18 years of age. The two rating systems were also compared. Results indicate that components of the same type in the two methods do not measure the same underlying factors, particularly for mesomorphy (anthroposcopic technique) and the second component (Health-Carter method). The methods cannot be considered as equivalent. The stability analysis reveals that the 'athletic' component tends to be less stable than the other two components, especially in the anthroposcopic Sheldon technique. In general, however, the constancy of the three somatotype components is fairly high during the growth period considered.

Adolescent↗
PubMedDate not supplied

Skeletal maturity in Belgian youths assessed by the Tanner-Whitehouse method (TW2).

Reference data for skeletal maturity (TW2 method) of the hand and wrist are provided for large representative samples of Belgian boys and girls. The sample of Belgian boys consisted of 21,174 boys aged 12 to 20 years studied in a nationwide cross-sectional and longitudinal study on the physical fitness of secondary schoolboys (1969-1974). The girls' sample consisted of 9698 6-19-year-old Flemish girls studied cross-sectionally (1979-1980). Both samples were multi-stage stratified cluster samples of entire school classes. All skeletal maturity assessments of the boys were made by the same observer (GB). His estimations agreed quite closely with those of the originators of the method. The skeletal age assessments of the girls were made by two observers trained by GB. Both observers showed high intraobserver reliability after training, and during the assessments. Moreover their ratings compared favourably with those of GB and the originators of the method. Smoothed percentile curves of the maturity scores (TW2-20 bone, RUS and CARP scores) were calculated by means of cubic splines using a stepwise regression procedure for the selection of suitable knots. In the boys, the TW2 scores (20 bone and RUS) increase linearly between 12 and 14.5 years of age, slow down for a while, and then increase again, while the CARP scores increase linearly between 12 and 15 years of age. In girls, the 20-bone maturity scores increase nearly linearly from 6 through 9.5 years of age, accelerate until 11.0 years followed by a smaller increase; RUS scores increase curvilinearly from 6 years of age onwards; and Carp scores increase almost linearly between 6.0 and 12.5 years of age. Belgian boys are advanced in RUS scores but are delayed for the carpal bones as compared with the British standards. The Belgian girls show advancement for both scales as compared with the British reference data. The skeletal maturation of youths from several other continental European countries corresponds more closely with the Belgian than with the British data. The reference data presented herein most probably provide suitable standards for youths of West-European countries.

Adolescent↗
PubMedDate not supplied

Prostaglandin-induced neonatal periostitis.

Prostaglandins are being commonly used to maintain the patency of the ductus arteriosus in infants with congenital ductal-dependent heart disease. A significant and unusual side effect of this drug treatment is the symmetrical development of periostitis of the long bones. A review of neonates with congenital heart disease requiring prostaglandin treatment at the Children's Hospital of Eastern Ontario revealed five infants who developed periostitis, the earliest onset being after 14 days of prostaglandin infusion. The drug dosage varied in these infants from 0.02 to 0.10 micrograms/kg/min. The periostitis was associated with limb pain and considerable swelling of the extremities in all children. The periostitis improved on cessation of the prostaglandin infusion, and by 6 weeks after the cessation of the drug, the periostitis had decreased significantly. Periostitis seemed more dependent on the duration of administration of the prostaglandin than on the dosage of prostaglandin administered. Awareness of this entity is essential not only for the treatment team caring for these infants but also for consultant pediatric orthopaedists to avoid excessive investigation for infection, metabolic disease, or vitamin deficiencies that resemble prostaglandin-induced periostitis.

Ductus Arteriosus, Patent↗