Article Text
Abstract
Background Neuropsychological capabilities in athletes may be associated with a predisposition to anterior cruciate ligament (ACL) injuries.
Objective Assess differences between male and female athletes in jump-landing technique in relation to their neuropsychological capabilities.
Design Experimental.
Setting Laboratory.
Participants 31 recreational athletes, free from lower extremity injuries, participated (females: n=16, age=21.0±1.71 years, mass=65.1±5.6 kg, height=174.2±68.9 cm; males n=15, age=22.3±2.2 years, mass=77.9±8.9 kg, height=185.7±78.7 cm).
Assessment of risk factors Reaction time (RT) under stress was measured. Furthermore, participants conducted anticipated (ANT) and unanticipated (UNANT) double-legged drop-jumps, followed by running at 4.5-5.5 m/sec 45° to the left, straight, or 45° to the right, depending on the light indication prior to landing on the force plates.
Main outcome measures RT and joint kinematics (trunk flexion-TF, ankle flexion-AF) and kinetics (knee abduction moment-KAM, ankle extension moment-AEM) at peak vertical ground reaction force (vGRF,N/kg). Moments are expressed as external moments (Nm/kg). Pearson product-moment correlation between RT and joint biomechanics.
Results During UNANT, KAM became significantly larger (P=.010) in females (–0.37±0.1) than males (–0.16±0.1). TF was greater in the AT (29.7°±3.3°) than UNANT (46.1°±3.1°) regardless of gender (P<001). AEM was smaller in females (2.1±0.1) than males (2.6±0.1), (P=.001). AF was smaller (i.e., increased flexion) when running straight (80.8°±0.8°) compared to the left or right (84.6°±0.7°, P=.002 and 84.2°±0.8°, P=.008). vGRF was smaller when running straight (22.8±1.0) compared to the left or right (31.5±1.0, P<.001 and 28.8±1.0, P<.001). Significant correlations (r 0.5-0.8, P<.05) were seen between faster RT and greater hip and knee flexion angle and smaller KAM and knee abduction angle.
Conclusions Females reacted differently to UNANT in the frontal plane, potentially placing them at greater ACL injury risk. In the sagittal plane, females showed stiffer ankle landing. Further, a change in direction increased vGRF. Smaller knee flexion combined with smaller TF angles during UNANT, may increase loads at the knee. Lastly, neuropsychological characteristics seem to affect ACL injury risk.