Changes in Drop-Jump Landing Biomechanics During Prolonged Intermittent Exercise

UNCG Author/Contributor (non-UNCG co-authors, if there are any, appear on document)
Robert A. Henson, Associate Professor (Creator)
Randy J. Schmitz, Associate Professor (Creator)
Sandra J. Shultz, Professor and Chair (Creator)
The University of North Carolina at Greensboro (UNCG )
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Abstract: Background: As injury rates rise in the later stages of sporting activities, a better understanding of lower extremity biomechanics in the later phases of gamelike situations may improve training and injury prevention programs.Hypothesis: Lower extremity biomechanics of a drop-jump task (extracted from a principal components analysis) would reveal factors associated with risk of anterior cruciate ligament injury during a 90-minute individualized intermittent exercise protocol (IEP) and for 1 hour following the IEP.Study Design: Controlled laboratory study.Level of Evidence: Level 4.Methods: Fifty-nine athletes (29 women, 30 men) completed 3 sessions. The first session assessed fitness for an IEP designed to simulate the demands of a soccer match. An experimental session assessed drop-jump biomechanics, after a dynamic warm-up, every 15 minutes during the 90-minute IEP, and for 1 hour following the IEP. A control session with no exercise assessed drop-jump performance at the same intervals.Results: Two biomechanical factors early in the first half (hip flexion at initial contact and hip loading; ankle loading and knee shear force) decreased at the end of the IEP and into the 60-minute recovery period, while a third factor (knee loading) decreased only during the recovery period (P = 0.05).Conclusion: The individualized sport-specific IEP may have more subtle effects on landing biomechanics when compared with short-term, exhaustive fatigue protocols.Clinical Relevance: Potentially injurious landing biomechanics may not occur until the later stages of soccer activity.

Additional Information

Sports Health. 2014;6(2)128-135.
Language: English
Date: 2014
principal components, drop landing, soccer, anterior cruciate ligament

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