As an expert in the field of human anatomy, I am well-versed in the intricate details of the musculoskeletal system. The leg is a crucial part of the human body, providing support, mobility, and balance. It is composed of various segments, each with its own unique structure and function. When we talk about the part of the leg below the knee, we are specifically referring to the lower leg, which is a region that extends from the knee joint to the ankle joint. The lower leg is a complex structure that houses several bones, muscles, and other tissues. It is anatomically divided into two main parts: the crus or cnemis (pronounced as /ˈniːmɪs/) and the calf. 1. Crus or Cnemis: This term is less commonly used in contemporary anatomy, but it historically refers to the entire lower leg. The crus is composed of two primary bones: the tibia and the fibula. The tibia, located on the medial side of the lower leg, is the larger and stronger of the two bones. It bears the majority of the body's weight and is commonly known as the shinbone. The fibula, on the other hand, is a thinner bone situated on the lateral side of the tibia. It plays a supportive role and is not typically involved in weight-bearing. 2. Calf: The calf is the muscular back portion of the lower leg. It is composed of two main muscles: the gastrocnemius and the soleus. The gastrocnemius is the larger and more superficial muscle, which is responsible for plantar flexion of the foot and is often referred to as the "lump" seen when the calf muscle is flexed. The soleus is a deeper muscle that lies beneath the gastrocnemius and also contributes to plantar flexion. Together, these muscles are essential for walking, running, and jumping. In addition to the bones and muscles, the lower leg also contains numerous other structures such as tendons, ligaments, blood vessels, and nerves. The Achilles tendon, for instance, is a strong fibrous cord that connects the calf muscles to the heel bone (calcaneus), facilitating powerful plantar flexion movements. The lower leg is also encased in a layer of connective tissue known as the fascia, which provides support and protection to the underlying muscles and bones. The fascia of the lower leg is particularly thick, forming a structure called the crural fascia. Understanding the anatomy of the lower leg is not only important for medical professionals but also for athletes and individuals interested in physical fitness. Injuries to this region, such as shin splints, calf strains, or ankle sprains, are relatively common and can significantly impact a person's mobility and quality of life. In conclusion, the part of the leg below the knee is called the lower leg, which includes the crus or cnemis and the calf. This region is a marvel of biological engineering, combining strength, flexibility, and functionality to support a wide range of human activities. read more >>

In human anatomy, the lower leg is the part of the lower limb that lies between the knee and the ankle. ... The leg from the knee to the ankle is called the crus or cnemis /?ni?m?s/. The calf is the back portion, and the tibia or shinbone together with the smaller fibula make up the front of the lower leg.read more >>