What does the Q angle indicate?

The Q angle, or quadriceps angle, is a critical measurement in assessing lower limb alignment, particularly in relation to the knees. It represents the angle formed between two reference points: a line drawn from the anterior superior iliac spine (the bony prominence on the pelvis) to the center of the patella (kneecap) and a line from the center of the patella to the tibial tuberosity.

The significance of the Q angle lies in its role in identifying potential alignment issues that could lead to knee problems or injuries, especially during activities like running. A larger Q angle can indicate misalignment, which may predispose runners to issues such as patellar tracking problems or other knee injuries. Thus, understanding the Q angle helps coaches and trainers assess biomechanical factors that can affect performance and the risk of injury.

The other options do not accurately describe the concept or relevance of the Q angle. The ankle's angle, toe alignment, and knee flexion are all important factors in running biomechanics, but they are not defined by the Q angle measurement.