Q-ANGLE - EFFECTS OF ISOMETRIC QUADRICEPS CONTRACTION AND BODY POSITION

The quadriceps femoral angle (Q angle) has been linked with several kn ee disorders, but Q-angle measurement procedures have not been standar dized. The purpose of this study was to examine the effects of isometr ic quadriceps contraction in the standing and supine positions on the Q angle. The Q angles of the right knees of 30 men and 30 women were m easured goniometrically during four test conditions: 1) quadriceps rel axed in standing, 2) quadriceps contracted in standing, 3) quadriceps relaxed in supine, and 4) quadriceps contracted in supine. The pelvic widths were also measured as the distance between the anterior superio r iliac spines in standing and supine. A two-way multivariate analysis of variance showed a significant difference between genders (p < 0.00 1) and among the four test conditions (p < 0.001) (N = 60). Separate o ne-way analyses of variance (ANOVAs) with two grouping factors (contra ction and position) showed significant effects of contraction (p < 0.0 01) for both men and women, but no significant effect of positions. A dependent t-test showed that the pelvic width differed between standin g and supine for both men and women (p < 0.001). The results showed th at isometric quadriceps contraction affects the Q angle with the subje cts standing or supine, even though the pelvic width differed signific antly between the two positions. Clinicians and researchers should con sider the results of this study in order to standardize procedures for measuring the Q angle.