Presenter : Richard Howey
Mentor : Li-Shan Chou
Major : Human Physiology
Poster 11
Full 3D kinematic analysis is often used for biomechanical assessment of running mechanics and corresponding injury risk. However, conclusions drawn from these analyses are highly dependent on data analysis methods. For example, poor hip joint extension (HJE) at toe-off is often interpreted clinically as resulting from weakness in extensor muscles. However, because joint angles are often calculated as movement of the distal segment relative to the proximal, two absolute orientations may result in the same calculated joint angle. Therefore, poor HJE could result in movements of the thigh or the pelvis. The purpose of this study is to compare hip joint, thigh seg- ment and pelvic tilt angles in runners with good and poor HJE. Data from this study were drawn from a database of 100 runners who had been analyzed in the motion analysis laboratory. Ten individuals with HJE 1.5 standard deviations above and below the database mean comprised the good and poor groups, respectively. While the two groups were different in HJE (good: M = -15.28° ± 1.34°; poor: M = 3.51° ± 4.94°; p < .001) the angle of the thigh segment relative to vertical was not different between groups (good: M = 3.52° ± 8.38°; poor: M = 3.41° ± 4.94°; p = .991). The pelvis angles also were significantly different between groups (good: M = -4.88° ± 8.76°; poor: 7.17° ± 8.03°; p = .005). These findings suggest that pelvic instability should be considered in addition to weakness in hip exten- sors when reduced HJE is observed.