Calf muscles: anatomy. In simple and accessible language

Leg mobility, stability and coordination of human movements - all this would be impossible without the lower leg. The part of the leg located between the knee and ankle joints is the most important functional section in the anatomy of the musculoskeletal system. The skeletal and muscular systems of the lower leg, developed in accordance with age standards, are the basis that provides most of the motor activity, including walking, running and other movements of the body in space. Let's figure out how the human lower leg is structured, what determines its functionality and how they can be improved.

Anatomical structure of the leg bones

The skeletal system of the lower leg is structured quite primitively and includes only two large bones - the tibia and fibula. Both of them are quite strong, since they are partly responsible for maintaining the human body in an upright position, forming gait and serving as support for the body.

Tibia

The tibia is larger because it serves as a supporting bone. The expansion at the top, forming two condyles, serves as the point of articulation with the large femur, forming the knee joint. Here, but a little more laterally, there is another condyle, thanks to which the tibia and fibula are connected into a single skeletal system.

The body of the tibia has the shape of a triangular prism with a base on the posterior side. The inner and outer sides of the bone form an acute angle - the front edge of the bone, which, if desired, can be felt with slight pressure on the surface of the leg. In the upper part of the anterior edge, in the popliteal region, a pronounced tuberosity is formed, to which the most powerful tendons and muscles of the lower leg are attached.

The lower end of the bone also widens towards the base, forming a noticeable protrusion - the medial malleolus. The lumpy surface of the base connects to the bones of the foot, forming the ankle joint.

Fibula

Compared to the tibia, the fibula looks thin and fragile. In fact, this is not entirely correct: although it is much narrower, its density is not inferior to that of the tibia. In the upper part, the fibula has a head, which, matching in size with the lateral condyle of the tibia, forms a strong articulation.

The lower portion of the fibula also expands to form the lateral malleolus. It protrudes noticeably above the surface of the shin, so it can be easily felt without even straining the leg.

Danger of sprained ankle

A sprained ankle (ankle) is a very common injury.

It can be obtained at any age, regardless of whether a person is physically active or leads a quiet lifestyle. There are many reasons for a dislocation: high-heeled shoes, an unnoticed step, an unsuccessful landing during a jump...

What happens when you sprain your ankle? Three bones meet at the ankle joint and are held in place by the joint capsule and ligaments. An ankle sprain is actually a sprain or tear of the ligaments of the joint, causing damage to the joint capsule.

There are four wide ligaments on the inner side, and two thin ones on the outer side. Therefore, it is extremely difficult to tuck the leg outward, but relatively easy to tuck inward.

People with weak foot and leg muscles, flat feet and overpronation have a much greater chance of getting a dislocation. By strengthening the muscles, we strengthen the fixation of the ankle, help the ligaments and thereby reduce the risk of injury.

Features of the articulation of the bones of the lower leg

The tibia and fibula are connected from above through a flat joint, which belongs to the group of inactive ones. This joint is additionally immobilized by a fairly strong ligamentous apparatus that holds the complex. Along the entire length of the tibia, between the bones there is an interosseous membrane, which passes downwards into the syndesmosis, connecting the lower ends of the tibia and fibula.

Calf muscles: anatomy, classification and functions

The bone structures of the lower leg are surrounded by a dense ring of muscles, thanks to which the leg remains mobile, starting from the foot and ending with the knee. Depending on the location, all muscles are classified into three separate groups: anterior, posterior and lateral. The anterior group of muscle fibers is responsible for supination, extension and adduction of the foot, as well as extension of the toes. The posterior group acts as an antagonist and controls the flexion of the foot and toes. And the muscles belonging to the lateral group control abduction, pronation and flexion of the foot.

Anterior muscles

The tibialis anterior muscle is located throughout the lower leg, starting in the upper part of the interosseous membrane and ending at the medial cuneiform and first metatarsal bones of the foot. Its functions include extension and supination of the foot. In the ankle area, it is crossed by the upper and lower ligaments, which hold the extensor tendons. The body of the muscle can be easily palpated on the front surface of the leg, especially in the area of the transition to the ankle joint, where its tendon noticeably protrudes with increased extension of the foot.
The extensor toe longus muscle is a multi-articular muscle that begins at the superior edge of the tibia and fibula and, dividing into four tendons on the surface of the foot, is attached to the distal phalanges of the 2nd to 5th toes. And although the main function of this muscle is the extension of the toes, it is also partially involved in the extension and pronation of the foot.
The extensor pollicis longus muscle is the smallest and weakest muscle among the group under consideration. It begins in the lower part of the leg and is attached to the surface of the distal phalanx. In addition to extension of the big toe, this muscle is involved in supination and extension of the foot.

Lateral muscles

The peroneus longus muscle completely covers the bone of the same name, covering the lateral malleolus from above and is attached between the outer surface of the fibula and the first metatarsal bone. In the area of the transition to the heel bone, it is held in place by a dense interweaving of ligaments (lower and upper tendon retinaculum). Thanks to this muscle, a person can perform flexion, abduction and pronation of the foot.
The peroneus brevis muscle serves as an agonist of the peroneus longus muscle, responsible for pronation, abduction and flexion of the foot. It originates at the interosseous septum, wraps around the ankle from below and is secured at the fifth metatarsus.

Posterior muscles

The triceps muscle is the most powerful and voluminous among the muscles of the leg. It is located on the back surface and forms the so-called calves - a protruding part, especially developed in athletes. Two of the three heads - the medial and lateral gastrocnemius - are located superficially, and the third - the soleus - lies in the deep layers. All three heads of the triceps muscle unite into one unit at the heel bone, forming the Achilles, or heel, tendon. The functions of the triceps muscle are extremely multifaceted. The gastrocnemius heads flex the knee and ankle joints, and the soleus head flexes the foot. In addition, the heads of the gastrocnemius muscle take part in the formation of the rhomboid popliteal fossa, through which the main nerve bundles and vessels supplying the thigh and lower leg pass.
The plantaris muscle is rudimentary, so it does not always appear in the anatomy of the lower leg. It begins at the knee joint and goes down, running slightly medial to the center. In the lower part of the leg, the muscle is transformed into a thin longitudinal ligament, which lies in the thickness of the triceps muscle, between the soleus and gastrocnemius heads. Going down to the heel bone, the plantaris ligament intertwines with the Achilles tendon, forming a single complex.
The popliteus muscle is adjacent to the posterior plane of the knee joint. It has a short, flat shape and is partially attached to the articular capsule of the knee, which allows it to pull back the capsule wall when the leg is bent. In addition, the popliteus muscle is involved in flexion and pronation of the lower leg.
The tibialis posterior muscle is adjacent directly to the bone structures and is hidden under the body of the triceps. Together with the inner wall of the soleus muscle, it forms a narrow ankle-popliteal canal through which the main part of the blood vessels and nerve fibers of the lower limb passes. Also, the tibialis posterior muscle plays the role of a flexor and supinator of the foot.
The flexor digitorum longus is an antagonist of the extensor muscle, which belongs to the group of anterior muscles of the leg. This muscle begins at the posterior wall of the tibia, is divided into four tendons and is attached to the plantar surface of the distal phalanges of the 2nd to 5th toes. The functionality of the flexor longus affects not only the fingers, but also the foot: thanks to the coordinated contraction of this muscle, flexion and supination of the leg at the ankle occurs.
The flexor pollicis longus muscle is the strongest of the deep posterior muscles. It connects the lower part of the fibula and the distal phalanx of the big toe, causing flexion of the foot and the toe itself when contracted.

Diagnostics

Osteogenic leg cancer is easily diagnosed on the front of the leg. If it is on the back, then it is much more difficult to diagnose because of the calf muscle, which hides the tumor.

Superficial cancer of the soft tissues of the leg is also much easier to diagnose than asymptomatic deep cancer of the soft tissues of the leg.

If cancer of the leg is suspected, laboratory tests are performed, a computed tomography scan is performed, an X-ray of the leg is taken, and magnetic resonance imaging is performed.

A biopsy is done to confirm leg cancer. Next, it is checked whether leg cancer has metastases in other organs.

Strengthening the muscles and bones of the lower leg

Despite its high functionality, the anatomy of the lower leg is quite simple. This part of the lower extremities is easy to train, thanks to which you can significantly strengthen the muscular frame of the human body. The lower leg muscles, especially the back ones, can become much stronger even with regular walking, not to mention special exercises aimed at developing the legs. Jogging and walking at a fast pace, gymnastics, yoga or athletics - all this allows you to develop your lower legs, make them more stable and strong, which can subsequently protect you from problems with the musculoskeletal system.

In addition, the condition of the muscles and bones of the lower leg, as well as the entire body, will be positively affected by a healthy lifestyle, regular walks in the fresh air, especially on a cloudless day, when the body can receive an additional dose of vitamin D under the influence of sunlight. , as well as proper nutrition, rich in vitamins and microelements. To keep your bones strong and able to cope with high stress, eat the following foods:

chia seeds, sesame seeds, cabbage, figs, turnips, spinach, white beans, almonds are the main sources of calcium;
corn, barley, oats, wheat, broccoli, beans, pumpkin and sunflower seeds rich in phosphorus;
almonds, cashews, spinach, bran, sweet potatoes, beans, thanks to which you can compensate for magnesium deficiency;
seaweed, chanterelles and yeast are food sources of calciferol;
leafy vegetables, cabbage, green tomatoes and lettuce - they contain vitamin K.

And, of course, it is worth taking into account the water balance in the body’s cells, because without a sufficient amount of fluid, the muscles will quickly weaken and lose elasticity. By following these recommendations, you will be able to keep your legs in ideal physical shape, which will serve as an excellent prevention of diseases of the musculoskeletal system.

FUNCTIONAL ANATOMY OF THE MUSCULAR SYSTEM | HIP FLEXORS