Thigh Muscles

Muscles of the Thigh

The thigh is divided into three major compartments – the anterior, medial and posterior – each of which contains different muscles.

Muscles in the Anterior Compartment of the Thigh

The anterior compartment of the thigh contains five muscles, which are as follows:

• Sartorius
• Rectus femoris
• Vastus lateralis
• Vastus intermedius
• Vastus medialis

These muscles form part of the quadriceps, which are the four large muscles at the front of the thigh. This muscle group is responsible for straightening the leg at the knee joint, as well as providing stability around the knee joint to protect it from injury.

Muscles in the Medial Compartment of the Thigh

The medial compartment of the thigh contains five muscles, which are as follows:

• Gracilis
• Adductor longus
• Adductor brevis
• Adductor magnus
• Pectineus

These muscles make up a group known as the adductors, which are responsible for adduction, or the action of drawing the thigh inwards towards the center of the body, as well as assisting with hip flexion and external rotation of the hip joint.

Muscles in the Posterior Compartment of the Thigh

The posterior compartment of the thigh contains four muscles, which are as follows:

• Biceps femoris
• Semitendinosus
• Semimembranosus
• Short head of the biceps femoris

These muscles make up the hamstrings, which play a key role in hip extension, knee flexion, and external rotation of the hip joint. The hamstrings also play a role in stabilizing the hip joint, as well as providing power and propulsion during activities such as running, jumping, and kicking.