Abstract
Injuries to the anterior cruciate ligament (ACL) are occurring at higher rates in sports today. Female athletes make up over halfofthe injury cases. Multiple theories have been proposed; suggesting more than one factor is responsible for causing an ACL injury. In gender comparison studies looking at different tasks women tend to have different neuromuscular control patterns and play sports in a more erect posture. This study investigated a place kick. Both male and female soccer players in high school and college volunteered for this study. Twenty subjects were divided into four groups based on gender and level. Each subject was filmed using three optical cameras (60 Hz) while performing a series ofkicking trials. Joint angles ofthe hip, knee, ankle, as well as, vertical (VGRF), medialllateral (MGRF/LGRF), and anterior/posterior (AGRFIPGRF) ground reaction force ofthe support leg were determined using Vicon-Peak Motion Analysis system with MOTUS software and AMTI force plate (600 Hz). Statistical differences between gender and level were analyzed using an ANOVA (p= .05). All four groups averaged less than 30 degrees ofknee flexion. Between 0 and 30 degrees ofknee flexion places the ACL under the most strain. Statistical differences were found for the ankle for gender (p= .008) and level (p= .005). Male subjects produced more dorsiflexion than female subjects. This suggested that women used their gastrocnemius more than their hamstring for knee flexion. This increases the injury potential ifthe gastrocnemius and hamstring do not work together to counter balance an aggressive quadriceps contraction. Also high school subjects produced significantly more dorsiflexion than college subjects. This combined with higher PGRF in high school subjects suggested inexperience could cause them to land harder and possibly increase their injury potential.