Gender, Structure and Activity: Variables Affecting Knee Kinematics

Recent research pertaining to landing and knee injury has focused on neuromuscular control of the knee, particularly on the hamstrings and quadriceps. The influence of hip neuromuscular control and lower extremity structural alignment has not been thoroughly explored. The first purpose is to document the effect of fatigue of the hip musculature on landing kinematics. The second purpose is to examine the relationship of commonly used structural assessments with landing kinematics. Specifically, we will examine the influence of gender (male, female), structure, activity type (cutting, non-cutting) and level offatigue (Pre, Post) on kinematic motion of the knee during landing from a single leg forward jump. Three different populations will be studied and include: females in non-cutting sports (n= 15), females in cutting sports (n= 15), and males in cutting sports (n= 15). Structural dependent variables include: arch index, and Difference of Hip Rotation (DOHR). Kinematic dependent variables assessed via electromagnetic motion analysis include: angular position at contact and peak joint displacement for knee flexion, knee rotation and knee valgus (deg). Prior to the jumping task, structural variables of the preferred leg will be measured. Subjects will then complete three pre-fatigue jumps. Next, subjects wiJI complete a hip external rotation/abduction isometric fatigue protocol. Immediately following fatigue, subjects will complete three additional jumps. Repeated measure ANOV A's will be performed to assess differences between gender, activity type, and fatigue. Pearson Correlations will be used to assess relationships between variables. We anticipate that there will be differences in landing kinematics between gender, structure, activity and fatigue.