In physiology, the names of muscles and the name of bones are often derived from other terns like Latin or Greek words. The word “Vastus” is derived from the Latin word meaning vast. The literal meaning of vast is expansive or large. The Vastus muscles are three different muscles that help make up the four muscled quadriceps group. As the name implies, it is the largest muscle group present in the human body.

The vastus muscles are located in the frontal area of the upper leg. It is known as the anterior compartment that is situated in-between the hip and the knee. All the three vastus muscles originate in the thigh bone that is known as femur and attach done over the knees on the knee cap that is known as patella.

Each of the three vastus muscles are situated at different spots present inside the anterior compartment of the thigh muscles. The nomenclature of each of the muscles is guided by the location in which they are located. The vastus lateralis is located in the lateral side. It is the largest of all the three muscles under the vastus caterogy. It also stretches the furthest length. The specific task of the vastus lateralis is to extend up to the lower leg and enable the body to increase up from a squatting position. Some of the common injuries of the vastus lateralis include strains and contusions. Strain tear in the muscle and results from an improper warm uo before the conduction of the physical activity. On the other hand, contusion occurs when the muscle is crushed against any bones resulting from a high impact bruising injury.

Vastus medialis is the second form of the vastus muscles. It is an extensor muscle that is situated medially in the thing, extending up to the knees. It is a part of the quadriceps muscle group. A division of vastus medialis muscles into the groups of fibre include vastus medialis longus, vastus medialis obliquus. Injury in the medialis portion results in chronic knee pain.

The third muscle in this group includes vastus intermedius muscle. It is situated underneath the rectus femoris, vastus lateralis and the vastus medialis. It originates at the lateral and the anterior surface of the upper-thirds of the femoral shaft and the lower protion of the lateral intermuscular spetum. The muscle is commonly fused with the vastus medialis muscle and is inserted deep inside the tendons of the muscle and extends up to the lateral aspect of the patella and the lateral condyle of the tibia. It mainly functions as the knee extension.

The main function of all the three vastus muscle is to conduct the flexion of the knees that movement of the lower portion of the leg in order to shorten the angle between the hip and the ankle. The vastus muscles also help in standing up from the sitting position by initiating movements in the hip extension. It also aid in running, jumping and normal walking.