Immediate changes in the quadriceps femoris angle after insertion of an orthotic device

Objective: To measure changes in the quadriceps femoris angle (Q-angle) after the insertion of full-length flexible orthotics. Setting: Outpatient health center of Logan College of Chiropractic. Subjects: A total of 40 male subjects were included in the study population. The selected population all demonstrated bilateral pes planus or hyperpronation syndrome. Design: Before-after trial. Method: A cohort demonstrating bilateral hyperpronation was recruited. The subjects were cast according to standard protocols provided by the manufacturer. Subject right and left Q-angles were measured with and without the orthotic in place. The landmarks used were marked with a permanent marker, and great care was taken to accurately assess the angles formed. The evaluator was not told whether the measure was before or after orthotic insertion. A modified quailcraft goniometer was used. Data Analysis: The data set was collected and assessed by the t test. Results: Thirty-nine of 40 test subjects showed reduced Q-angle, which was in the direction of correction. A 2-tailed matched sample showed statistically significant mean reduction in Q-angle measures. There was a minority of patients who showed asymmetrical Q-angle measures. Within this group there was greater symmetry of Q-angle measures after placement of the orthotic. Conclusion: Insertion of full-length, flexible orthotic devices significantly improves the Q-angle in hyperpronating male subjects. If the literature accurately links an increase in the Q-angle with a predisposition for knee injury, then the possibility of long-term benefits following the use of flexible orthotics exists. More research is required to determine whether these biomechanical changes are maintained after use of these orthotics.