Anatomy & Organs

Musculus quadriceps femoris – structure, function & diseases

Musculus quadriceps femoris

The so-called quadriceps femoris muscle is located on the abdominal side (front or ventral side) of the thigh and consists of four different muscle heads. That is why it is colloquially referred to as the four-headed thigh extensor, four-headed thigh muscle or quadriceps.

What is the quadriceps femoris muscle?

The quadriceps femoris muscle is the anterior skeletal muscle of the thigh . Since it consists of four different parts (called muscle heads), it is often also called the four-headed thigh muscle, four-headed thigh extensor or quadriceps.

On average, it is more than 150 cm² wide and is therefore one of the strongest muscles in the human body. Due to its width, it significantly shapes the side contours and the front of the thigh and gives them their shape. If the quadriceps are affected in their function, this can have a significant impact on the entire movement function when walking and standing.

Anatomy & Structure

The quadriceps are made up of four different parts, which in medical jargon are called muscle heads. These four distinct muscle parts are known as the rectus femur (also called rectus femoris ), the medial broad muscle ( vastus medialis muscle ), the middle broad muscle (also called vastus intermedius muscle ), and the outer broad muscle ( vastus muscle ). lateralis ) titled. 

Each individual muscle head has its own tasks and functions, which ultimately affect the overall function of the quadriceps femoris muscle. The rectus femoris muscle arises from both the anterior bony prominence of the pelvis (Spina iliaca anterior inferior ) as well as on the upper edge of the pelvic socket (medically called acetabulum ). The fibers end in the common tendon of attachment, the quadriceps tendon. The vastus medialis muscle is divided into two parts. 
One portion spirals from the longest crest of bone of the thigh ( linea aspera ) over the anterior bony side ( linea intertrochanterica ) of the femoral bone and around the shaft of the bone, eventually merging into the quadriceps tendon. The second part bypasses the kneecap towards the body and attaches over the kneecap ‘s retaining ligament ( retinaculum patellae mediale ) to the medial articular process ( condylus medialis ).) of the shinbone ( tibia ). 
The vastus lateralis muscle arises from the linea aspera, winds around the bony shaft of the femur and largely merges into the quadriceps tendon. The vastus intermedius muscle, on the other hand, begins at the front of the femur and ends in the tendon of insertion.

Function & Tasks

The quadriceps is also known as the four-headed thigh extensor because it is the only extensor muscle in the knee joint. For this reason, it plays a crucial role in almost all movements in which the legs are required. Extension of the knee is necessary when walking or getting up from a sitting or lying position, but also when climbing stairs. In addition, the quadriceps femoris muscle prevents the knee joint from buckling when standing and walking.

It also strengthens and supports the hip joint and has a significant effect on the rotation of the knee joint. This means that it also influences movements that take place in the lower part of the legs. If the quadriceps are injured or impaired, there will be severe movement disorders. 

To a lesser extent, these can make walking or standing more difficult. In the event of a severe failure of the quadriceps femoris muscle, however, it can also happen that the leg buckles completely at the knee joint and the affected person is unable to put weight on it successfully. In other cases, the quadriceps femoris muscle contracts uncontrollably, which also leads to disturbed movement sequences.

In addition to the functions required for movement, the quadriceps femoris muscle also has protective tasks: when the knee is stretched, the quadriceps prevents the surrounding tendons , nerves and tissue from being pinched between the kneecap and the thigh bone by addressing the correct muscle groups.

Diseases & Ailments

The function of the four-headed thigh muscle can be disrupted both by external influences and by diseases of the body (such as the intervertebral discs ). Typical injuries to the quadriceps are strains of the individual muscle heads, which can occur, for example, as a result of overexertion during sports or accidents. These usually manifest themselves in pain that restricts mobility. Depending on the severity and type of injury, the symptoms and limitations can last from several days to weeks. 

However, the quadriceps are also disrupted in their function by herniated discs or by strokes in which the nerve roots L3 and L4 or the patellar tendon reflex (PSR) have been impaired or abolished. In this case, there is less pain than numbness and paralysis. As a result, the quadriceps relaxes or only contracts uncontrollably, so that it is no longer possible or very difficult to carry out the movement sequences controlled by it.

The rectus femoris muscle is one of the shortest muscles in the body. For this reason, of all human muscles, it’s the most prone to injury – ultimately affecting the entire quadriceps. Because when the rectus femoris muscle shortens over time, it affects the full length of the quadriceps as well. A progressive shortening of the quadriceps femoris muscle can be counteracted by regular stretching exercises in which the foot is slowly and carefully pulled towards the buttocks .

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.