Final answer:
Inability to evert the patella is indicative of patellofemoral syndrome, also known as runner's knee. It is caused by an imbalance in the quadriceps femoris muscle and can be treated by resting the knee and strengthening the muscle.
Step-by-step explanation:
Inability to evert the patella is indicative of patellofemoral syndrome, also known as runner's knee. This condition is the most common overuse injury among runners and is characterized by a dull, aching pain in the front of the knee. It occurs due to an imbalance in the quadriceps femoris muscle, which leads to abnormal tracking of the patella toward the lateral side.
To treat patellofemoral syndrome, it is important to rest the knee and gradually resume activity. Strengthening the quadriceps femoris muscle can help correct the imbalances and prevent the reoccurrence of the condition.