Gender variation of bilateral Q-angle in young adult Nigerians.

BACKGROUND: The quadriceps femoris angle (Q-angle) is an important indicator of biomechanical function in the lower extremities. It is a quantitative measurement of patella position in respect to the lower extremity alignment. OBJECTIVE: This study was designed to determine gender variation of bilateral Q-angle values in young adults and also to check for symmetry in individual participants. METHODS: A total of 800 participants (400 males and 400 females), who were recruited consecutively participated in the study. They had no history of knee pain or musculoskeletal disorders and no obvious limb length discrepancy. Their ages ranged from 18 to 30 years. They were selected using a non-probability sample of convenience. The Q-angle was measured bilaterally using the universal goniometer with the participants in the erect weight bearing position. The data were analyzed using the independent t - test at 95% confidence interval. RESULTS: The Q-angle valves in the male participants were 14.7 degrees +/- 2.1 for left and 13.0 degrees +/- 1.7 for right lower limbs respectively, while in the female participants, Q-angle values were 16.8 degrees +/- 1.3 and 15.3 degrees +/- 1.0 for left and right lower limbs respectively. Female participants had significantly higher Q-angle values than their male counterparts. The left lower limb recorded a significantly higher Q-angle value in both males and females than right lower limb (p < 0.05). CONCLUSION: Q-angle is bilaterally asymmetric in an individual and higher in female, hence Q-angle measurement should always be bilateral, irrespective of whether one or both knees are involved.