This information is provided for guidance only and cannot be used as a diagnosis of your condition. It is designed to help you get some clarity about your problem, so you can discuss it further with an expert and obtain an accurate diagnosis.
The upper leg is the region between the hip and knee and comprises the single bone, the femur, and has the main locomotive muscles of the body, the quadriceps at the front of the thigh and the hamstrings at the back. The quads are responsible for sustaining steady walking and running and the hamstrings for explosive acceleration in running.
Balancing of strength between the quads and hamstrings is important for correct knee function and further, the balance between the four quads is critical for the correct tracking of the kneecap, or patella.