Muscles of the Knee (Cross-section View)

The muscles of the knee include the quadriceps, hamstrings, and a few other muscles. These muscles help extend, flex, and rotate the knee. The large, fleshy group of muscles called the quadriceps femoris occupies the front and sides of the thigh and is the primary extensor of the knee. The four parts (rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius) of these muscles attach to the patellar tendon, which passes over the front of the knee and attaches to the knee cap....

Click to read more below

Anatomy Terms

Change Anatomical System

Knee Joint, Cross-section

Change View Angle

Full Muscles of the Knee (Cross-section View) Description

[Continued from above] . . .

The hamstring muscles (semitendinosus, semimembranosus, and the biceps femoris) help to flex the knee. These muscles pass along the back of the thigh and connect close to the midline ends of the fibula and tibia. The hamstring can be felt as a ridge behind the knee.

Some other muscles that help the knee move include the popliteus muscle (which helps the leg rotate inward), the articularis genus muscle (which elevates the capsule of the knee joint), dorsal and plantar flexor muscles, plantaris muscle, peroneus brevis muscle, sartorius muscle (which flexes the leg at the knee joint and rotates it slightly after flexing), and the tibialis anterior muscle. With these and the hamstring and quadriceps muscles, the leg couldn't bend, straighten or twist, meaning the body couldn't walk, run, kick and do other similar movements with the legs.