Influence of Q-angle on Lower Extremity Running Kinematics

Graham E. Caldwell, Joseph Hamill, Bryan C. Heiderscheit

Study Design: Two-group posttest-only comparison. Objective: To assess the influence of the Q-angle on the 3-dimensional lower extremity kinematics during running. Background: An excessive Q-angle has been implicated in the development of knee injuries by altering the lower extremity locomotion kinematics. Previous investigations using 2-dimensional analyses during walking did not support this hypothesis. Methods and Measures: We hypothesized that individuals with Q-angles more than 15° would display an increase in rearfoot eversion and tibial internal rotation during running. Thirty-two nonimpaired subjects (men: n = 16, mean age = 22 ± 3 years; women: n = 16, mean age = 23 ± 3 years) ran over ground, and 3-dimensional kinematic data were collected from the right lower extremity. Subjects with a Q-angle of 15° or less comprised the low-Q-angle group, whereas those with Q-angles of more than 15° comprised the high-Q-angle group. Segment and joint maximum angles and the times when the maxima occurred during stance were measured. Results: The Q-angle magnitude did not increase the maximum segment or joint angles during running. The groups displayed similar maximum angles for rearfoot eversion (low Q-angle, -15.5 ± 5.0°; high Q-angle, -15.6 ± 6.6°) and tibial internal rotation (low Q-angle, -8.8 ± 4.8°; high Q-angle, -6.8 ± 5.1°). The high-Q-angle group (39.5 ± 16.3%) achieved maximum tibial internal rotation later in the stance phase than the low-Q-angle group (28.8 ± 10.7%). Conclusions: In support of the previous investigations involving Q-angle influences on kinematics, our study did not reveal any differences between groups in maximum joint or segment angles. The kinematic information did reveal that the high-Q-angle group displayed an increase in time to maximum tibial internal rotation. The impact of this single factor on producing knee injury is unknown. J Orthop Sports Phys Ther. 2000;30(5):271-278. Key Words: segment alignment, 3-dimensional kinematics, tibial rotation

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