Quadriceps
The quadriceps femoris muscle (/ˈkwɒdrɪsɛps ˈfɛmərɪs/, also called the quadriceps extensor, quadriceps or quads) is a large muscle group that includes the four prevailing muscles on the front of the thigh. It is the sole extensor muscle of the knee, forming a large fleshy mass which covers the front and sides of the femur. The name derives from Latin four-headed muscle of the femur.
Not to be confused with quadratus femoris.Quadriceps femoris muscle
Combined rectus femoris and vastus muscles
musculus quadriceps femoris
Function[edit]
All four quadriceps are powerful extensors of the knee joint.[1][4] They are crucial in walking, running, jumping and squatting. Because the rectus femoris attaches to the ilium, it is also a flexor of the hip.[1][4] This action is also crucial to walking or running, as it swings the leg forward into the ensuing step. The quadriceps, specifically the vastus medialis, play the important role of stabilizing the patella and the knee joint during gait.[5]
Clinical significance[edit]
The quadriceps femoris muscle is a target for manual therapy and physical therapy from repetitive strain injuries, such as from skiing.[6]
The quadriceps femoris muscle is the most common site of myositis ossificans.[7]
Etymology[edit]
The proper Latin plural form of the adjective quadriceps would be quadricipites. In modern English usage, quadriceps is used in both the singular and plural form. The singular form quadricep, produced by back-formation, is frequently used.
Cross-section through the middle of the thigh
The quadriceps forms the bulk of front part of the thigh
