Muscles of the lower limb

Muscles of the Lower Limb

The muscles of the lower limb are essential components of the human body, playing a crucial role in movement and stability. These muscles are categorized based on their location into the hip, thigh, leg, and foot muscles. They are responsible for actions such as walking, running, jumping, and maintaining posture.

Hip Muscles

The hip muscles are primarily involved in the movement of the hip joint. They can be divided into four major groups: the gluteal muscles, the lateral rotator group, the iliopsoas, and the adductor group.

Gluteal Muscles

• Gluteus maximus: The largest and most superficial of the three gluteal muscles, responsible for extension, abduction, and external rotation of the hip.
• Gluteus medius and Gluteus minimus: These muscles lie beneath the gluteus maximus and are involved in the abduction and medial rotation of the hip.

Lateral Rotator Group

This group includes the piriformis, obturator internus, obturator externus, superior gemellus, inferior gemellus, and quadratus femoris. They primarily act as lateral rotators of the hip.

Iliopsoas

The iliopsoas is a composite muscle formed by the iliacus and the psoas major muscles. It is the primary flexor of the hip.

Adductor Group

The adductor group consists of the adductor longus, adductor brevis, adductor magnus, gracilis, and pectineus. These muscles mainly act to adduct the thigh.

Thigh Muscles

The thigh muscles are responsible for movements of the knee joint. They are divided into three compartments: anterior, medial, and posterior.

Anterior Compartment

The anterior compartment includes the quadriceps femoris, a group of four muscles that extend the knee. The quadriceps femoris consists of the vastus lateralis, vastus medialis, vastus intermedius, and the rectus femoris.

Medial Compartment

The medial compartment contains muscles that are primarily involved in the adduction of the thigh, similar to the adductor group of the hip muscles.

Posterior Compartment

The posterior compartment, or the hamstring group, includes the biceps femoris, semitendinosus, and semimembranosus. These muscles flex the knee and extend the hip.

Leg Muscles

The muscles of the leg are divided into anterior, lateral, and posterior compartments.

Anterior Compartment

The anterior compartment includes the tibialis anterior, extensor digitorum longus, extensor hallucis longus, and the fibularis tertius. These muscles primarily dorsiflex the foot and extend the toes.

Lateral Compartment

The lateral compartment contains the fibularis longus and fibularis brevis, which evert the foot.

Posterior Compartment

The posterior compartment is further divided into the superficial and deep groups. The superficial group includes the gastrocnemius, soleus, and plantaris, which together form the Achilles tendon and are involved in plantarflexion of the foot. The deep group includes the tibialis posterior, flexor digitorum longus, flexor hallucis longus, and popliteus, which mainly act to invert the foot and flex the toes.

Foot Muscles

The foot muscles, divided into dorsal and plantar groups, are responsible for the fine movements of the foot and toes.

Dorsal Group

The dorsal group includes the extensor digitorum brevis and the extensor hallucis brevis, which extend the toes.

Plantar Group

The plantar group is extensive and includes muscles such as the abductor hallucis, flexor digitorum brevis, abductor digiti minimi, quadratus plantae, and the lumbricals. These muscles are involved in supporting the arches of the foot and flexing the toes.