title: Predictors of proximal tibia anterior shear force during a vertical stop-jump.
abstract: Anterior cruciate ligament (ACL) continues to be a significant medical issue for athletes participating in sports and recreational activities. Biomechanical analyses have determined that anterior shear force is the most direct loading mechanism of the ACL and a probable component of noncontact ACL injury. The purpose of this study was to examine the biomechanical predictors of proximal tibia anterior shear force during a stop-jump task. A biomechanical and electromyographic (EMG) analysis of the knee was conducted while subjects performed a vertical stop-jump task. The task was chosen to simulate an athletic maneuver that included a landing with a sharp deceleration and a change in direction. The final regression model indicated that posterior ground reaction force, external knee flexion moment, knee flexion angle, integrated EMG activity of the vastus lateralis, and sex (female) would significantly predict proximal tibia anterior shear force (p < 0.0001, R2 = 0.8609). Knee flexion moment had the greatest influence on proximal tibia anterior shear force. The mathematical relationships elucidated in the current study support previous clinical and basic science research examining noncontact ACL injuries. This data provides important evidence for clinicians who are examining the risk factors for these injuries and developing/validating training programs to reduce the incidence of injury.
authors.affiliation: Neuromuscular Research Laboratory, Department of Sports Medicine and Nutrition, School of Health and Rehabilitation Sciences University of Pittsburgh, 3200 S. Water Street, Pittsburgh, Pennsylvania 15203, USA. tcs15@pitt.edu
authors.forename: Timothy C
authors.initials: TC
authors.lastname: Sell
authors.forename: Cheryl M
authors.initials: CM
authors.lastname: Ferris
authors.forename: John P
authors.initials: JP
authors.lastname: Abt
authors.forename: Yung-Shen
authors.initials: YS
authors.lastname: Tsai
authors.forename: Joseph B
authors.initials: JB
authors.lastname: Myers
authors.forename: Freddie H
authors.initials: FH
authors.lastname: Fu
authors.forename: Scott M
authors.initials: SM
authors.lastname: Lephart
mesh_terms: D000293:Adolescent; D016118:Anterior Cruciate Ligament / Q000502:physiology*; D000070598:Anterior Cruciate Ligament Injuries; D001696:Biomechanical Phenomena; D004576:Electromyography; D015444:Exercise / Q000502:physiology*; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000517:prevention & control; D007719:Knee Joint / Q000502:physiology*; D008297:Male; D052097:Quadriceps Muscle / Q000502:physiology*; D012737:Sex Factors; D013977:Tibia / Q000502:physiology*