TY - JOUR
T1 - Bilateral multidirectional jumps with reactive jump-landings achieve osteogenic thresholds with and without instruction in premenopausal women
AU - Clissold, Tracey L.
AU - Cronin, John B.
AU - De Souza, Mary Jane
AU - Wilson, Daniel
AU - Winwood, Paul W.
N1 - Publisher Copyright:
© 2019 Elsevier Ltd
PY - 2020/3
Y1 - 2020/3
N2 - Background: Currently jump-landing ground reaction forces have only been quantified in the vertical direction as a stimulus for bone development. This study quantified the full-spectrum of jump-landing force magnitudes (body weight's) and rates of strain (body weights per second) of bilateral multidirectional jumps (star jump and stride jump) with reactive jump-landings (i.e. jumping immediately after initial jump-landing) among premenopausal women. It was also of interest to quantify the influence of instruction on the magnitude and rate of the jump-landing ground reaction forces. Methods: Twenty-one women [Mean (SD): 43.3(5.9)yr; 69.4(9.6)kg; 167(5.5)cm; 27.5(8.7)% body fat] performed a jump testing session ‘with instruction’ followed by a jump testing session performed one week later with ‘instruction withdrawn’. Findings: The resultant magnitudes (3.90 to 5.38, body weights) and rates of strain (192 to 329, body weights per second) for the jump-landings, performed on a force plate, exceeded previously determined osteogenic thresholds (>3body weight's and >43body weights per second, respectively). An instruction effect was observed for resultant (↑8% and ↑12%; P ≤.01) and vertical (↑8% and ↑7%; P ≤.01) ground reaction force's (Newtons and body weight, respectively) indicating learning/practice effects for these exercises. A jump-landing effect was observed, with larger peak rates of strain (↑29%; P <.0001, body weight per second) and peak forces (↑12% to ↑48%; P ≤.01, body weights) for the second jump-landing (post-reactive jump). Interpretation: These multidirectional bilateral jumps represent a unique training stimulus for premenopausal women and achieve osteogenic thresholds thought pre-requisite for bone growth and could be utilized in the development of osteogenic exercise programs.
AB - Background: Currently jump-landing ground reaction forces have only been quantified in the vertical direction as a stimulus for bone development. This study quantified the full-spectrum of jump-landing force magnitudes (body weight's) and rates of strain (body weights per second) of bilateral multidirectional jumps (star jump and stride jump) with reactive jump-landings (i.e. jumping immediately after initial jump-landing) among premenopausal women. It was also of interest to quantify the influence of instruction on the magnitude and rate of the jump-landing ground reaction forces. Methods: Twenty-one women [Mean (SD): 43.3(5.9)yr; 69.4(9.6)kg; 167(5.5)cm; 27.5(8.7)% body fat] performed a jump testing session ‘with instruction’ followed by a jump testing session performed one week later with ‘instruction withdrawn’. Findings: The resultant magnitudes (3.90 to 5.38, body weights) and rates of strain (192 to 329, body weights per second) for the jump-landings, performed on a force plate, exceeded previously determined osteogenic thresholds (>3body weight's and >43body weights per second, respectively). An instruction effect was observed for resultant (↑8% and ↑12%; P ≤.01) and vertical (↑8% and ↑7%; P ≤.01) ground reaction force's (Newtons and body weight, respectively) indicating learning/practice effects for these exercises. A jump-landing effect was observed, with larger peak rates of strain (↑29%; P <.0001, body weight per second) and peak forces (↑12% to ↑48%; P ≤.01, body weights) for the second jump-landing (post-reactive jump). Interpretation: These multidirectional bilateral jumps represent a unique training stimulus for premenopausal women and achieve osteogenic thresholds thought pre-requisite for bone growth and could be utilized in the development of osteogenic exercise programs.
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U2 - 10.1016/j.clinbiomech.2019.12.025
DO - 10.1016/j.clinbiomech.2019.12.025
M3 - Article
C2 - 31896044
AN - SCOPUS:85077025764
SN - 0268-0033
VL - 73
SP - 1
EP - 8
JO - Clinical Biomechanics
JF - Clinical Biomechanics
ER -