Anticipatory Effects on Lower Extremity Neuromechanics During a Cutting Task.
BACKGROUND
Continued research into the mechanism of noncontact anterior cruciate ligament injury helps to improve clinical interventions and injury-prevention strategies. A better understanding of the effects of anticipation on landing neuromechanics may benefit training interventions.


OBJECTIVE
To determine the effects of anticipation on lower extremity neuromechanics during a single-legged land-and-cut task.


METHODS
Controlled laboratory study.


METHODS
University biomechanics laboratory.


METHODS
Eighteen female National Collegiate Athletic Association Division I collegiate soccer players (age = 19.7 ± 0.8 years, height = 167.3 ± 6.0 cm, mass = 66.1 ± 2.1 kg).


METHODS
Participants performed a single-legged land-and-cut task under anticipated and unanticipated conditions.


METHODS
Three-dimensional initial contact angles, peak joint angles, and peak internal joint moments and peak vertical ground reaction forces and sagittal-plane energy absorption of the 3 lower extremity joints; muscle activation of selected hip- and knee-joint muscles.


RESULTS
Unanticipated cuts resulted in less knee flexion at initial contact and greater ankle toe-in displacement. Unanticipated cuts were also characterized by greater internal hip-abductor and external-rotator moments and smaller internal knee-extensor and external-rotator moments. Muscle-activation profiles during unanticipated cuts were associated with greater activation of the gluteus maximus during the precontact and landing phases.


CONCLUSIONS
Performing a cutting task under unanticipated conditions changed lower extremity neuromechanics compared with anticipated conditions. Most of the observed changes in lower extremity neuromechanics indicated the adoption of a hip-focused strategy during the unanticipated condition.
Department of Exercise Physiology, Marquette University, Milwaukee, WI.
Carolyn M
CM
Meinerz
Department of Exercise Physiology, Marquette University, Milwaukee, WI.
Philip
P
Malloy
Department of Exercise Physiology, Marquette University, Milwaukee, WI.
Christopher F
CF
Geiser
Department of Exercise Physiology, Marquette University, Milwaukee, WI.
Kristof
K
Kipp
D000293:Adolescent; D016118:Anterior Cruciate Ligament / Q000502:physiology; D000070598:Anterior Cruciate Ligament Injuries; D059031:Anticipation, Psychological / Q000502:physiology*; D001696:Biomechanical Phenomena / Q000502:physiology; D005260:Female; D006615:Hip / Q000502:physiology; D006801:Humans; D007537:Isometric Contraction / Q000502:physiology; D007718:Knee Injuries / Q000503:physiopathology; D007719:Knee Joint / Q000502:physiology; D035002:Lower Extremity / Q000502:physiology*; D009068:Movement / Q000502:physiology; D018482:Muscle, Skeletal / Q000502:physiology*; D009142:Musculoskeletal Physiological Phenomena; D011597:Psychomotor Performance / Q000502:physiology; D012399:Rotation; D012916:Soccer / Q000293:injuries / Q000502:physiology*; D013848:Thigh / Q000502:physiology; D055815:Young Adult
anterior cruciate ligament; anticipation; biomechanics