european college of sport science

Friday, June 26th, 2009
[2] Del Monte A, Faina M(1999) Valutazione dell’atleta, Utet Torino, 457-458
[3] Leger LA, Lambert J (1982) J Appl Physiol, 49, 1-12
RELATIONSHIPS BETWEEN ANTHROPOMETRIC PARAMETERS AND BONE DENSITY IN 7-8-YEAR-OLD RHYTHMIC GYM-
NASTS
PARM, A., SAAR, M., PÄRNA, K., JÜRIMÄE, J., NEISSAAR, I., JÜRIMÄE, T.
UNIVERSITY OF TARTU
Introduction: Better bone density in childhood might prevent osteoporosis in later life (Baxter-Jones et.al., 2008). Prepubertal years are an
opportune time to increase bone mineral density (BMD) through exercise (Bass et.al., 1998). High-impact exercise has strong impact to
BMD and bone mineral content (BMC). Rhythmic gymnasts perform a lot of jumps and is known as high-impact bone loading sport. The
aim of the study was to investigate the influence of anthropometric (skinfolds, girths, lengths and breadths) and body composition (fat %,
fat mass, lean body mass - LBM) parameters to the BMD and BMC in young rhythmic gymnasts and same age controls.
Methods: Participants of this study were 89 7-9 year-old girls from different schools and sport clubs. They were devided to the rhythmic
gymnasts (n=46) and controls (n=43). Body height and body mass were measured and BMI was calculated (kg/m²). All anthropometric
parameters were measured according to the protocol recommended by the International Society for Advancement of Kinanthropometry.
BMI (g/cm³) and BMC (g) were determined by DXA. BMD and BMC were measured at lumbar spine (L2-L4) and femoral neck area.
Results: Gymnasts have significantly higher values in L2-L4 and femoral neck BMD compared to controls. Gymnasts have also higher
BMC values in L2-L4 and femoral neck compared to controls. Gymnasts had significantly lower values in skinfolds. Anthropometric values
and bone parameters have significantly more relationships in controls compared to gymnasts.
Discussion: Our results suggest that young rhythmic gymnasts body height, LBM and BMI are the same as in controls. However, in controls
body fat mass and fat % are significantly higher and BMD and BMC in L2-L4 and femoral neck have lower values than gymnasts.
From the anthropometric parameters skinfold thicknesses are thicker in controls, on the girths, lengths and breadths there are very few
significant differences between rhythmic gymnasts and controls.
References
Bass S, Pearce G, Bradney M, Hendrich E, Delmas PD, Harding A, Seeman E. (1998). J Bone Miner Res, 13, 500-7.
Baxter-Jones ADG, Kontulainen SA, Faulkner RA, Bailey DA. (2008). Bone, 43(6), 1101-1107.
GENDER EFFECTS ON VASTUS LATERALIS MUSCLE ARCHITECTURE IN PRE-PUBERTAL CHILDREN
TZIAGKALOU, E., ARABATZI, F., SAÈZ-SAEZ DE VILLARREAL, E., KANNAS, T.H., KELLIS, E.
LABORATORY OF NEUROMECHANICS
INTRODUCTION: Muscle force production is affected by architectural arrangements of fibers within the muscle (1). Many studies have
examined the relationship between architectural arrangement and muscle force (1). To our knowledge, there are no data on differences
in muscle architectural properties and force production in children, between boys and girls (2). Morse et al. (2) have been shown that
children display different pennation angle as well as fascicle length compared with adults. The determination of the relationship between
level of force and architectural characteristics may assist in identifying the mechanisms underlying growth effects on strength capacity in
relation to gender. The purpose of this study was to examine the effects of gender on pennation angle, fascicle length and thickness
values during isometric force production in pre-pubertal children.
METHODS: Twenty boys and girls (age= 11,2 ± 0,26 years, mass= 48,78 ± 9,15kg, height= 156,7 ± 7,28cm) participated in this study. All
tests were performed on a Kin Com dynamometer. In vivo muscle architecture was assessed using B-mode ultrasonography. Isometric
torque of the knee extensors was assessed at angles of 0° (full extension), 45° and 90°. The subjects performed three efforts at 100%, 0%,
40%, 60% and 80% of MVC. The total duration of each effort was 5 seconds. Subsequently pennation angle, thickness and fascicle length
were evaluated.
RESULTS: Analysis of variance with repeated measures showed that, fascicle length in point of gender changed as the level of muscle
effort and knee angle were altered (p