A muscle in the quadriceps, the rectus femoris muscle is attached to the hip and helps to extend or raise the knee. This muscle is also used to flex the thigh. The rectus femoris is the only muscle ...

The quadriceps, or quads, are a group of four muscles on the front of the thigh. They are some of the largest and strongest muscles in the body. The quad muscles allow a person to stand, walk, run, ...