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Full-Text Articles in Medicine and Health Sciences
Preferential Quadriceps Activation In Female Athletes With Incremental Increases In Landing Intensity, Kevin R. Ford, Gregory D. Myer, Laura C. Schmitt, Timothy L. Uhl, Timothy E. Hewett
Preferential Quadriceps Activation In Female Athletes With Incremental Increases In Landing Intensity, Kevin R. Ford, Gregory D. Myer, Laura C. Schmitt, Timothy L. Uhl, Timothy E. Hewett
Physical Therapy Faculty Publications
The purpose of this study was to identify alterations in preparatory muscle activation patterns across different drop heights in female athletes. Sixteen female high school volleyball players performed the drop vertical jump from three different drop heights. Surface electromyography of the quadriceps and hamstrings were collected during the movement trials. As the drop height increased, muscle activation of the quadriceps during preparatory phase also increased (p < .05). However, the hamstrings activation showed no similar increases relative to drop height. Female athletes appear to preferentially rely on increased quadriceps activation, without an increase in hamstrings activation, with increased plyometric intensity. The resultant decreased activation ratio of the hamstrings relative to quadriceps before landing may represent altered dynamic knee stability and may contribute to the increased risk of ACL injury in female athletes.
Spatiotemporal Postural Control Deficits Are Present In Those With Chronic Ankle Instability, Patrick O. Mckeon, Jay Hertel
Spatiotemporal Postural Control Deficits Are Present In Those With Chronic Ankle Instability, Patrick O. Mckeon, Jay Hertel
Physical Therapy Faculty Publications
BACKGROUND: Postural control deficits have been purported to be a potential contributing factor in chronic ankle instability (CAI). Summary forceplate measures such as center of pressure velocity and area have not consistently detected postural control deficits associated with CAI. A novel measurement technique derived from the dynamical systems theory of motor control known as Time-to-boundary (TTB) has shown promise in detecting deficits in postural control related to chronic ankle instability (CAI). In a previous study, TTB deficits were detected in a sample of females with CAI. The purpose of this study was to examine postural control in sample of males …