Leg Anatomy

Leg anatomy means the study of the leg of the human body. The two lower limbs of the body, provide support and a range of movements.

The leg contains five regions, they are as follows

• Upper leg 

• Knee 

• Lower leg 

• Ankle 

• Foot 

Leg Muscles 

Leg muscles consist of a number of long muscles, which help in stretching distances. The legs of human beings are the lower limbs of the body that provide movement and support for the individual. The structure of the leg muscles is dependent on the part of the leg. Let us learn about more different types of leg muscles, based on the parts of the legs like knee, ankle, feet and thighs. 

Parts of Leg Muscles 

The anatomy of the legs can be divided into upper leg muscles and lower leg muscles. 

1. Upper Leg Muscles

The upper legs consist of three main muscles:

 hamstrings, quadriceps and adductors. 

A. Hamstring: The hamstrings are those three muscles that are located in the back of the thighs. These muscles help us to allow the knees to flex and bend. Those three hamstring muscles are semimembranosus, semitendinosus and biceps femoris.

The semimembranosus muscle is connected to the pelvis and tibia through tendons. These muscles help to flex and rotate. These muscles help to rotate the tibia on the femur when the knee is flexed, and rotate the femur when the hips are stretched. The biceps femoris muscles help in stretching the thigh, bending the knee and rotating the knees outside the body.

B. Quadriceps: The quadriceps are those four muscles located in the front of the thighs. The quadriceps help to extend the knee from a bending degree. The four quadriceps muscles are vastus lateralis, vastus medialis and rectus femoris. 

The vastus lateralis muscles help to strengthen the lower leg and help us rise to a squatting position. For the knee muscles, the vastus medialis and the vastus intermedius helps us to extend. The rectus femoris muscles help in extending or rising the knee and also flex the thigh. The rectus femoris is the only muscle that can flex the hips of the human body.

C. Adductors: Adductors muscles consist of four muscles located inside the thigh. It binds the thighs together. The four adductor muscles are adductor longus, adductor brevis, obturator externus, adductor magnus and gracilis.

The adductor magnus pulls and contracts the hip towards the body’s midline, which allows activities like walking, sprinting, etc. The adductor longus is located in the skeleton of the thigh. 

The adductor brevis helps to flex and rotate the thigh by adducting the thigh at the hip joint. The obturator externus muscles, with other short muscles at the hip joint, help in the joint stability. The gracilis muscles are found in the groin and are responsible for hip adduction and knee flexion. 

Knee

The knee joints the upper leg and lower legs. It consists of knee bones, knee tendons and knee ligaments.

The Lower Leg

The five types of muscles consist of the lower leg namely, gastrocnemius, soleus, plantaris, tibialis muscles and peroneus muscles.

The gastrocnemius muscles are the primary muscles in the calves. Gastrocnemius muscles allow a movement that helps the toes to point downward. The soleus muscles help the knees and aid in walking and standing. 

The back of the lower leg small muscles are called plantaris. The tibialis muscles are located in the front and back part of the lower leg. In the front part of the lower leg are only places where peroneus muscles are situated - extensors, tibialis posterior, flexors, tibialis anterior and tibialis peroneal. 

Bones of the Leg 

The leg comprises three bones

• Femur 

• Tibia 

• Fibula 

The upper bone leg is known as the femur while the lower portion of the leg is the tibia and the fibula. 

Femur 

The thigh bone, or the femur, heaviest, strongest and longest in the entire human body. It can bear extreme forces which act upon the femur. The only bone located within the thigh is the femur. The femur supports the pelvic bone to the lower leg bones. The most important feature of the femur, that it forms a ball-and-socket joint with the hip. 

Tibia 

One of the two bones present in the lower leg is the tibia. It is also called the shank bone or the shinbone. Moreover, the tibia is the largest and strongest bone in the lower leg. According to the anatomy, the tibia connects the ankle bone with the knee. 

Fibula 

The fibula is known as the calf bone and connects to the tibia upper and lower. It is located within the lateral aspect of the leg. The fibula's main function is to act as a connection for muscles, and not as the weight bearing. The fibula has three main articulates with the lateral condyle of the tibia.