Effects of single-leg drop-landing exercise from different heights on skeletal adaptations in prepubertal girls: a randomized controlled study.
Pediatr Exerc Sci
; 20(2): 211-28, 2008 May.
Article
em En
| MEDLINE
| ID: mdl-18579901
ABSTRACT
Few studies have explored osteogenic potential of prepubertal populations. We conducted a 28-week school-based exercise trial of single-leg drop-landing exercise with 42 prepubertal girls (6 to 10 years) randomly assigned to control (C), low-drop (LD) or high-drop (HD) exercise groups. The latter two groups performed single-leg drop-landings (3 sessions/week-1 and 50 landings/session-1) from 14 cm(LD) and 28 cm(HD) using the nondominant leg. Osteogenic responses were assessed using Dual Energy X-ray Absorptiometry (DXA). Single-leg peak ground-reaction impact forces (PGRIF) in a subsample ranged from 2.5 to 4.4 x body-weight (BW). No differences (p > .05) were observed among groups at baseline for age, stature, lean tissue mass (LTM), leisure time physical activity, or average daily calcium intake. After adjusting for covariates of body mass, fat mass and LTM, no differences were found in bone mineral measures or site-specific bone mineral density (BMD) at the hip and lower leg among exercise or control groups. Combining data from both exercise groups failed to produce differences in bone properties when compared with the control group. No changes were apparent for between-leg differences from baseline to posttraining. In contrast to some reports, our findings suggest that strictly controlled unimodal, unidirectional single-leg drop-landing exercises involving low-moderate peak ground-reaction impact forces are not osteogenic in the developing prepubertal female skeleton.
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Base de dados:
MEDLINE
Assunto principal:
Estatura
/
Adaptação Fisiológica
/
Exercício Físico
/
Puberdade
/
Músculo Esquelético
/
Perna (Membro)
Tipo de estudo:
Clinical_trials
Limite:
Child
/
Female
/
Humans
Idioma:
En
Revista:
Pediatr Exerc Sci
Ano de publicação:
2008
Tipo de documento:
Article
País de afiliação:
Austrália