Hips Don't Lie: Hip Potentiation Predicts Jump in Children

Research Objectives: To investigate the joint-specific biomechanical potentiation of the lower limb during jump test performance in children. Further, to examine the best predictor among variables of joint-specific biomechanical potentiation for the jump height enhancement in children.

Design: Cross sectional

Setting: University Research laboratory.

Participants: Healthy children (N = 20; age = 8 - 14 years)

Interventions: Not applicable.

Main Outcome Measures: Body weight normalized peak extensor joint moments, positive power, and work were calculated for the hip, knee, and ankle during countermovement (CMJ) and static jump (SJ). Joint-specific biomechanical potentiation was calculated as the ratio of CMJ/SJ for moment, power, and work values. Jump height (JHt) was calculated as the distance from the standing upright to the highest recorded point of the greater trochanter reflective marker using a motion capture system. Ratio of CMJ/SJ JHt was used to estimate JHt potentiation.

Results: CMJ/SJ ratios of the extensor moment (r = 0.548; p = 0.012), positive power (r = 0.547; p = 0.013), and positive work (r = 0.677; p = 0.001) at the hip were positively correlated with the CMJ/SJ ratio of JHt in children, even after adjusting for body height. CMJ/SJ ratio of the positive work at the hip was the only significant predictor of JHt , (rpartial = 0.471; p = 0.048) in children.

Conclusions: Results of our study provide novel data on the relationships of lower extremity joint-specific biomechanical potentiation variables with JHt enhancement in children. Specifically, our data suggests the importance of strength and power training of the hip for improving JHt in children.

Author(s) Disclosures: None.