What do you call the lower part of your legs? Decoding Leg Anatomy

October 2, 2025 •

2 min read

While most people refer to the area below the knee as simply the 'lower leg,' the anatomical term for this region is the crus. Understanding the specific names for different parts of your body is key to better communication in health and fitness contexts. So, what do you call the lower part of your legs in detail?

Quick Summary

The lower part of the leg, extending from the knee to the ankle, is anatomically known as the crus, which includes the shinbone (tibia) at the front and the calf muscles at the back.

Key Points

Anatomical Terminology: The scientific term for the lower leg, the area between the knee and ankle, is the crus.
Key Bones: The lower leg contains two main bones: the large, weight-bearing tibia (shinbone) and the smaller, stabilizing fibula.
Muscle Compartments: The muscles are divided into several compartments, including the posterior (calf) for pointing toes and the anterior (shin) for lifting the foot.
Common Ailments: Issues like shin splints, calf strains, and Achilles tendinopathy are common lower leg problems, often stemming from overuse.
Weight-Bearing Function: The entire lower leg is crucial for all weight-bearing activities, providing the strength and support needed for standing, walking, and running.
Injury Prevention: Stretching, warming up, and maintaining a healthy weight are key strategies for keeping your lower leg muscles and tendons healthy and avoiding injury.

Demystifying the Crus: More Than Just 'Lower Leg'

Though "lower leg" is a common and simple way to refer to the area below the knee, anatomically, this region is the crus. This section explores the bones, muscles, and functions of this vital part of your anatomy.

The Bony Framework

The lower leg's structure is supported by two long bones, the tibia and the fibula.

Tibia (Shinbone): The larger, medial tibia is the primary weight-bearing bone, connecting the knee and ankle joints.
Fibula: The thinner, lateral fibula is important for muscle attachments and the ankle joint, though it bears less weight.

The Major Muscle Groups

Lower leg muscles are organized into compartments.

Posterior Compartment (The Calf)

This rear compartment (the calf) contains muscles for plantar flexion (pointing toes), like the gastrocnemius, soleus, and plantaris.

Anterior Compartment

Located at the front, this compartment's muscles, including the tibialis anterior, are responsible for dorsiflexion (lifting the foot).

Lateral Compartment

Muscles on the outer side, such as the fibularis (peroneus) longus and brevis, primarily handle eversion (turning the foot outward).

Function and Common Problems

The lower leg is essential for weight-bearing activities, but is susceptible to issues. Common problems include shin splints, muscle strains, Achilles tendinopathy, and stress fractures. Serious conditions like deep vein thrombosis (DVT) can also cause pain and swelling.

Comparison of Lower Leg Anatomy


Anatomical Region	Common Term(s)	Primary Bones	Main Functions
Crus (Lower Leg)	Lower Leg, Calf, Shin	Tibia, Fibula	Weight-bearing, mobility, ankle joint movement
Posterior Compartment	Calf	N/A (contains muscles)	Plantarflexion (pointing toes)
Anterior Compartment	Shin	N/A (contains muscles)	Dorsiflexion (lifting foot)

Conclusion: A Detailed Look Below the Knee

Understanding the anatomical term crus for the lower leg, along with its bones and muscle compartments, provides a more precise view of this crucial region's role in movement and support. Maintaining lower leg health through proper care is vital for preventing common injuries and ensuring mobility. Consult a healthcare provider for persistent pain.

For more detailed anatomical information, you can visit Kenhub.

Frequently Asked Questions

The most common terms used to refer to the lower part of your legs are the calf, which is the muscular area at the back, and the shin, which is the area at the front dominated by the tibia bone.

In medical and anatomical contexts, the lower leg, or the portion between the knee and the ankle, is called the crus. This is distinct from the entire lower limb, which includes the thigh and foot.

There are two main bones in the lower leg: the tibia, also known as the shinbone, and the fibula. The tibia is the larger of the two and bears most of the body's weight, while the fibula provides muscle attachments and forms part of the ankle.

The calf muscle is located in the posterior, or back, compartment of the lower leg. It is made up of two main muscles, the gastrocnemius and the soleus, which join to form the Achilles tendon.

The lower leg is crucial for movement because its muscles and bones facilitate essential actions like walking, running, and jumping. The muscles control movements at both the ankle and knee joints, providing propulsion and stability.

A very common overuse injury is shin splints, which causes pain along the shinbone. Other common injuries include calf strains and Achilles tendon issues, especially in athletes or those who engage in high-impact activities.

Not always. While pain can result from injuries like strains or fractures, it can also indicate underlying issues such as poor circulation (e.g., peripheral artery disease), nerve problems (e.g., sciatica), or medical conditions like deep vein thrombosis (DVT).