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 yrs) 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/wk−1 and 50 landings/session−1) from 14cm(LD) and 28cm(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 × 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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Effects of Single-Leg Drop-Landing Exercise from Different Heights on Skeletal Adaptations in Prepubertal Girls: A Randomized Controlled Study
Peter N. Wiebe, Cameron J. R. Blimkie, Nathalie Farpour-Lambert, Julie Briody, Damian Marsh, Allan Kemp, Chris Cowell, and Robert Howman-Giles
Motor Unit Firing Properties During Force Control Task and Associations With Neurological Tests in Children
Masamichi Okudaira, Ryosuke Takeda, Tetsuya Hirono, Taichi Nishikawa, Shun Kunugi, and Kohei Watanabe
study, simple neurological tests have been utilized to detect neurological abnormalities. In particular, reaction time (RT) and single-leg standing (SLS) tests may be useful to clinically evaluate patients with motor neurological disorders, such as cerebral palsy, muscular dystrophy, and Parkinson
Effects of Integrative Neuromuscular Training on Fitness Performance in Children
Avery D. Faigenbaum, Anne Farrell, Marc Fabiano, Tracy Radler, Fernando Naclerio, Nicholas A. Ratamess, Jie Kang, and Gregory D. Myer
The aim of this study was to evaluate the effects of integrative neuromuscular training (INT) during physical education (PE) class on selected measures of health- and skill-related fitness in children. Forty children from two 2nd grade PE classes were cluster randomized into either an INT group (n = 21) or a control (CON) group (n = 19). INT was performed 2x/wk during the first ~15 min of each PE class and consisted of body weight exercises. INT and CON participants were assessed for health- and skill-related fitness before and after 8 wks of PE with or without INT, respectively. A significant interaction of group by time was observed in INT participants with improvements noted in push-ups, curl-ups, long jump, single leg hop, and 0.5 mile (0.8 km) run performance (p < .05). These data indicate that INT is an effective and time-efficient addition to PE as evidenced by improvements in health- and skill-related fitness measures in children.
Mediolateral Postural Control Mechanisms and Proprioception Improve With Kicking Sports Training During Adolescence
Mariève Blanchet and François Prince
), and this is what allows the efficient control of dynamic posture during predictable and unpredictable fast center of pressure (COP) displacements ( 9 , 28 , 34 , 43 , 65 ). The specialized movements in KS include a variety of body weight transfers and single-leg stances while applying a large amount
Agility Ladder Training Combined With Plyometric or Multidirectional Speed Drills: Short-Term Adaptations on Jump, Speed, and Change of Direction Performance in Young Female Volleyball Players
Eleni Bassa, Afroditi C. Lola, Alexandra Melliou, Maria Prassa, Georgia Stavropoulou, and Nikolaos Ziogas
, backward, and returning every time to the center (J) 1 × 2 reps 2 × 5 single-leg CMJs (1 set/leg) 1 × 24 m shuffling along the lines of a cross, forward, to the right, to the left, backward, and returning every time to the center (K) 2 × 2 reps 1 × 6 tuck jumps over plates 2 × 24 m shuffling along the
Speed Improves With Eccentric Hamstring Training in Athletes of Different Maturity Status
Raouf Hammami, Javier Gene-Morales, Ammar Nebigh, Haithem Rebai, and Juan C. Colado
0.542 years ( 29 ). Training Program The 6-week (2 d/wk) EHT intervention consisted of 5 exercises focused on the hamstrings and glutes (Figure 1 ): the glute hamstring raise, manual glute hamstring rise, single-leg Romanian deadlift, hip thrust, and good morning dumbbell or barbell. The between
The Influence of Acute Hypoxia on Oxygen Uptake and Muscle Oxygenation Kinetics During Cycling Exercise in Prepubertal Boys
Max E. Weston, Neil Armstrong, Bert Bond, Owen W. Tomlinson, Craig A. Williams, and Alan R. Barker
Physiol . 2003 ; 95 ( 1 ): 113 – 20 . doi: 10.1152/japplphysiol.00956.2002 15. DeLorey DS , Shaw CN , Shoemaker JK , Kowalchuk JM , Paterson DH . The effect of hypoxia on pulmonary O 2 uptake, leg blood flow and muscle deoxygenation during single-leg knee-extension exercise . Exp Physiol
