Effects of vastus medialis oblique-focused and general quadriceps strengthening exercises on Q-angle and quadriceps strength in overweight and obese females: A randomized controlled trial

Background: Genu valgum is a condition characterized by an abnormal angling of the knee joints, causing the knees to tilt inward and the feet to rotate outward. This condition is commonly observed in overweight individuals, particularly females, due to abnormalities in body structure and muscle function, specifically in the quadriceps and vastus medialis obliquus (VMO) muscles. Such abnormalities can affect the Q-angle, and an increased Q-angle may lead to patellar instability and stress on the knee joint. Previous studies have indicated that exercises aimed at strengthening the quadriceps and VMO muscles can help reduce the Q-angle. Objectives: This study aimed to compare the effects of VMO-focused strengthening exercises and general quadriceps strengthening exercises on the Q-angle and quadriceps strength in females with overweight and obesity. Materials and methods: Twenty females with overweight and obesity were randomly divided into two groups of 10. The first group participated in an exercise program focused on strengthening VMO muscle, while the second group engaged in a program aimed at improving quadriceps strength. Both programs lasted for 4 weeks and were conducted 3 days a week. Measurements of the Q-angle and quadriceps muscle strength were taken one week prior to the start of the exercises and again after the completion of the 4-week program. Data were analyzed using a two-way mixed analysis of variance (ANOVA) to examine the effects of group (VMO vs. quadriceps) and time (pre- vs post-). Results: The mixed ANOVA revealed no significant group × time interactions for Q-angle or quadriceps strength (all p>0.05). Both groups demonstrated similar patterns of change over time, with descriptive data indicating reductions in Q-angle and increases in quadriceps strength following the intervention. Conclusion: Both VMO-focused and general quadriceps strengthening exercises produced similar changes in Q-angle and quadriceps strength over the 4-week intervention period. No significant differences were observed between the two exercise approaches. These results should be interpreted with caution because of the short intervention duration. Future studies employing longer training periods and more objective measures of muscle activation are warranted to better elucidate potential differences between exercise types and to strengthen the evidence base in this area.