Final answer:
Femoral torsion relates to the diagonal orientation of the femur in the thigh, with a normal Q-angle of 10-15 degrees. A larger Q-angle, often seen in females, can lead to an increased risk of patellofemoral syndrome due to lateral pull on the patella during knee extension.
Step-by-step explanation:
The term femoral torsion refers to the degree of twist in a person's femur (thigh bone) and is related to the angle known as the Q-angle. The Q-angle measures the lateral deviation of the femur from a vertical line drawn through the tibia. A normal Q-angle is between 10-15 degrees. This angle is typically larger in females due to their wider pelvis, which results in a greater diagonal orientation of the femur within the thigh as compared to the vertically oriented tibia in the leg. An increased Q-angle can cause the quadriceps femoris muscle to pull the patella (kneecap) laterally during knee extension, potentially leading to patellofemoral syndrome, especially in females with a larger Q-angle.