Which muscle of the quadriceps femoris group lies on the side surface of the lower extremities?
A.
Anterior tibialis
B.
Rectus femoris
C.
Gastrocnemius
D.
Vastus lateralis
The correct answer and Explanation is :
The correct answer is D. Vastus lateralis.
The quadriceps femoris is a group of four muscles located in the front of the thigh that work together to extend the knee. These muscles are crucial for activities such as walking, running, and jumping. The quadriceps femoris consists of the following four muscles:
- Rectus femoris: This muscle is located in the middle of the front of the thigh. It is the only muscle of the quadriceps group that crosses both the hip and knee joints, contributing to hip flexion and knee extension.
- Vastus lateralis: This muscle is positioned on the lateral (outer) side of the thigh. It is the largest of the quadriceps muscles and plays a key role in extending the knee.
- Vastus medialis: This muscle is situated on the medial (inner) side of the thigh. It works alongside the vastus lateralis to extend the knee and stabilize the patella.
- Vastus intermedius: This muscle lies deep to the rectus femoris and is located between the vastus lateralis and vastus medialis on the front of the thigh.
Among these, the vastus lateralis is the one that lies on the side surface of the lower extremities. Its primary function is to extend the knee joint, which is essential for various movements and stability. It is a prominent muscle that contributes to the overall shape and strength of the thigh, and its position on the lateral aspect makes it particularly important for stabilizing the knee during activities that involve leg movement and weight-bearing.
In summary, the vastus lateralis is a key muscle in the quadriceps group, essential for knee extension and maintaining knee stability, and is located on the outer surface of the thigh.