Muscle Origin Points
The femur serves as the origin point for a total of twenty-three individual muscles. Within the thigh, three out of the four quadriceps muscles begin here, namely the vastus lateralis, vastus medialis, and vastus intermedius, all located on the front side of the thigh. These muscles play a crucial role in enabling the knees to straighten from a bent position. Apart from the quadriceps, other significant muscles originate from the femur as well. One of these is the popliteus muscle, responsible for unlocking the knee joint. Additionally, the gastrocnemius muscle, originating from the femur, allows for flexion of both the knee and ankle.
Muscle Insertion Points
Muscle insertion points refer to the locations where muscles are attached and where movement occurs. In the case of the thigh, there are five adductor muscles that play a crucial role in stabilizing the hip bone. These muscles stretch from the pelvis to the femur and include the adductor magnus, adductor longus, adductor brevis, and obturator externus. Positioned on the inside of the thigh, these adductor muscles are responsible for various movements.
The adductor longus, in particular, serves as a key muscle for moving the thigh towards the median axis of the body and also aids in laterally rotating the thigh. On the other hand, the back of the thigh is dominated by three hamstring muscles: the semimembranosus, semitendinosus, and biceps femoris. These muscles allow for the bending of the knee.