ArticleNorth American journal of sports physical therapy : NAJSPT2009
Peak biomechanical variables during bilateral drop landings: comparisons between sex (female/male) and fatigue (pre-fatigue/post-fatigue).
Article in North American journal of sports physical therapy : NAJSPT, 2009. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 3 papers, 1 of them a synthesis that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
3 citing papers in PubMed, 1 synthesis or guideline pooled it.
- Pooled it
- Is there a difference in knee biomechanics due to fatigue of the quadriceps versus hamstrings during landing on a single limb? a randomized comparative laboratory study.BMC sports science, medicine & rehabilitation · 2026Article
- Prospective Predictors of Patellofemoral Pain Syndrome: A Systematic Review With Meta-analysis.Sports health · 2012Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
5 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundAlthough anterior cruciate ligament (ACL) sprains usually occur during the initial phase of the landing cycle (less than 40° knee flexion), the literature has focused on peak values of knee angles, vertical ground reaction force (VGRF), and muscle activity even though it is unclear what occurs during the initial phase of landing.
objectivesThe objectives of this study were to determine the effects of sex (male and female) and fatigue (prefatigue/post-fatigue) on knee flexion angles at the occurrence of peak values of biomechanical variables [knee valgus angle, VGRF, and normalized electromyographic amplitude (NEMG) of the quadriceps and hamstring muscles] during a bilateral drop landing task.
methodsKnee valgus angle, VGRF, and NEMG of the quadricep and hamstring muscles were collected during bilateral drop landings for twenty-nine recreational athletes before and after a fatigue protocol.
resultsPeak values of knee valgus, VGRF, and NEMG of medial and lateral hamstring muscles occurred during the late phase of the landing cycle (>40° of knee flexion). Females in the post-fatigue condition exhibited peak VGRF at significantly less knee flexion than in the pre-fatigue condition. Males in the post-fatigue condition exhibited peak lateral hamstring muscles NEMG at significantly higher knee flexion than in the pre-fatigue condition. DISCUSSION AND
conclusionPeak values of biomechanical variables that have been previously linked to ACL injury did not occur during the initial phase of landing when ACL injuries occur. No biomechanical variables peaked during the initial phase of landing; therefore, peak values may not be an optimal indicator of the biomechanical factors leading to ACL injury during landing tasks.
Identifiers
21509113PMC2953325What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.