Leg structure and function

The structure of the legs - a very complex idea of nature. The bones that are inside the legs are the largest of the bones of the whole body. But nature conceived it not in vain, because the legs are the most powerful load of all parts of the body - they hold all the human mass. If a person has obesity, the bones and joints of the legs are doubly stressed. Read more about the structure and role of bones and joints.

[1], [2], [3]

How do bones grow?

In girls, bones grow up to 16 years old, and in boys - up to 17 years old. They gradually harden. When a child is small, his bones are soft and brittle, they are easy to break and damage, because the bones are mostly made from cartilage. As a person grows, cartilage hardens, they look more like bones, they are not so easy to break or injure.

When a person grows up, the cartilage remains in his joints only. Without cartilage tissue in the joints, the bones could not easily slide in contact with each other, and the person could not bend arms, legs and other parts of the body where there are joints. For example, turning the neck. Thanks to the joints, the bone tissue is not erased, as it would have happened without them.

[4], [5], [6]

Leg structure

They consist of the three largest pelvic bones - the sciatic, iliac, and pubic. It is these bones that give the body support and support the legs. By the age of 18, in both boys and girls, these bones grow together. This adhesion of three bones is called the swivel cavity.

In this cavity, as in the designer, the head of the bone of the thigh is inserted. It rotates and thus enables a person to freely and easily rotate a limb. The hip bone is so strong that it can freely withstand the weight of a passenger car.

In the knee joint there is a calyx that connects to the bone of the thigh, but not connected to the bone of the tibia. Therefore, the lower part of the leg and the knee with the help of bones and joints are connected, and this part of the leg thanks to the joints is mobile.

As for the knee, it is the most complex and durable design of all the joints of the body.

[7],

Foot structure

As we already wrote in the material about the structure of the foot, it consists of 26 bones - a huge amount for such a small foot. The bones of the foot have division: phalanxes of the fingers and metatarsal bones. The bones, which are located in the foot, make up two arches of the sole. They are arranged longitudinally. They enable the foot to be flexible and move dynamically in different directions. During walking, the foot acts as a spring, spring. A person is diagnosed with flat feet, if the function of the spring is impaired, that is, the arch of the foot is lowered in the same way as under the toes and heels.

[8]

Why do we need cartilage?

They help the joints not to wear off or become inflamed when the joints rub against each other. Therefore, the bones outside the joints are covered with cartilage tissue, which is elastic and allows the heads of the bones to slide against each other. And the role of lubricant between the heads of the joints with cartilage on them is performed by the synovial fluid. This fluid produces a membrane, which is called synovial. As soon as fluids are not sufficiently produced, the joints can no longer slide against each other, and therefore the person is very limited in movement.

Very rarely, but there are cases when the cartilage begins to harden and become bone. Then the joints can no longer rotate and move, because the bones grow together. The leg of the person becomes motionless, any movements in the direction of flexion-extension, turns cause pain. It is necessary to prevent the overgrowth of joints in the bones in advance, so as not to lose the mobility of the legs.

The role of the ligaments of the legs

Bundles tend to attach to the bones of the legs. Bundles consist of connective tissue, it is quite strong. Ligaments are needed to fix the joints in a certain position so that their movement, state of rest and any other functions are stable and reliable.

Bundles can break (this is well known to athletes), if you give them too much load. When the ligaments break, it is very painful and it takes a lot of time to repair the ligaments. If the bonding of bones is given for 21 days along with rehabilitation, then it may take 2 times longer to unite the torn ligaments.

To ligaments are not torn, it is important to exercise them: stretch, warm through exercise.

If a person hardens his ligaments, then the joints work much easier and better. As for the tendons, their structure is similar to the structure of the ligaments, but they differ from the ligaments in their role. The ligaments connect the bones, and the tendons connect the bones and muscles.

Leg muscles

The muscles need the legs in order to secure the bones and give them the opportunity to move. Muscles are divided into groups, and these groups are often multidirectional. This makes it possible for a person to move as he plans, and to exclude movements that are opposite in direction.

The part in front of the thigh consists of four muscles. They are the strongest of all the other bones of the human body. This is the most representative group of muscles, which are collectively referred to as the quadriceps muscle. She has a very important role - she is responsible for flexing the leg.

For the fold of the leg and thigh is the so-called tailor muscle. From this the shin is obtained the property to rotate, only inward, and the thigh rotates outward. Other muscle groups - leading and medial - allow the thigh to rotate inward, and thanks to them, you can keep the hip from the body and attach to it.

Muscles of the foot

The foot rises and falls due to the muscles of the leg, which give such an opportunity. Muscles tend to attach tendons to bones, which are located in the feet. Thanks to two external muscles, the shin has the ability to lower the foot down, thanks to these muscles and the sole is bent. The muscles, which are located on the back of the lower leg, help to raise the heel, as well as lift on tiptoe.

The foot has as many as 11 muscles, small in size and volume. These muscles help to unbend and flex the toes, to tear off the foot from the surface of the floor, that is, to go. 11 muscles - this is not all, to enable a person to walk, a total of 38 muscles with different functions are needed.

Lazy muscles

If the muscles of the legs are not trained, they become flabby and overgrown with fatty deposits, this does not perform its roles well. With thighs, fat is the last to go, even if the person is on a tight diet. It is important to constantly give power to the muscles, only to calculate it correctly. Particular attention should be paid to the buttocks and thighs, training them. Then the legs will serve a person for a long time and efficiently.

[9], [10], [11], [12]

Foot circulation

The blood moves through large-sized arteries, through small-sized arteries and through capillaries. So that they normally provide the feet with nutrients, blood needs oxygen. And it needs to be enriched with oxygen.

Arteries of the legs are different: at the location they are called femoral, anterior and posterior tibial, popliteal, dorsal (serves to supply blood to the foot), lateral and medial (located on the sole). The blood flow in these arteries is very strong, so the movement of blood can be felt even by putting a finger on the skin above the artery.

The walls of the arteries depend on the size of these arteries. If the size is large, then the walls are thick, and the blood runs stronger, since such an artery has a larger diameter. The composition of the walls - connective tissue. Smaller arteries have thinner walls that are composed of smooth muscle tissue. When the walls of the arteries contract, the blood runs through the arteries faster and more actively.

[13]

Capillaries

The smallest and narrowest vessels of the leg (and the whole body) are called capillaries. Their walls are very thin, they have a thickness of one cell of the body. Such walls are made not too thick because the process of exchanging oxygen and nutrients is faster in the capillaries. Capillaries feel very subtle changes in heat and cold. If a person gets into cold conditions, the capillaries narrow, and then the heat in the body is retained more. And if the hot temperature - the capillaries expand. Then the body can regulate the temperature, lowering it.

Metabolism enters the venules (small veins) from the blood capillaries, then they are transferred to the veins. Through the bloodstream, these substances are transported to the heart, and then to the lungs. There they are enriched with oxygen, giving off carbon dioxide.

In the legs are 8 major large veins. They converge in one femoral vein. In these veins there are special valves that help distill the blood in the right direction. This blood moves with the help of the muscles of the legs, which move it to the heart when the muscles contract. Because of this, in order for the heart to be healthy, doctors recommend walking and walking, especially before bedtime.

[14], [15]

Nerves located in the legs

All the movements that our foot makes are due to the motor nerves. On them commands of a brain are transferred. In addition to the motor ones, there are also sensory nerves in the leg, which transmit signals to the brain that a person was injured, that the leg hit the ice or set foot on hot asphalt.

Nerves of the legs take their origin from the lower back and sacrum (spinal sections of the same name). The largest region of the femur receives and transmits signals through the femoral nerve, the nerve of the perineum, and also the tibial and subcutaneous nerves are responsible for the leg impulses. The sole of the foot is controlled by the medial, gastrocnemius and lateral nerves.

Of course, these nerves do not exist by themselves. They are interconnected, and the impulse transmitted by one nerve can transmit to others. That is why pain in one part of the body can respond in another part of it. In addition, the interconnected system of nerves in different parts of the legs allow you to move the limbs as you like.

[16], [17]

Load on feet and their size

Previously, a person could use his toes as he uses his fingers. Toes a person could catch on a branch and hang on it or take some necessary object, for example, a stick. Now the functions of the foot have become less diverse, we limit the legs only to walking.

The foot has become much wider and more than a few centuries ago, because now a person does not climb trees, but holds his body weight thanks to his legs. Accordingly, the load on them has increased. And it is always easier to rely on a larger foot area than on a smaller one. Because every year the average minimum shoe size increases. This is indicated by the statistics.

[18], [19], [20]

What foot is considered perfect

Since the most important role of the foot is to withstand the weight of the body, it must have an optimal shape. The shape, strength, elasticity and size of the feet, and hence their health, depend on it. How to check the shape of your own feet?

Prepare a clean white sheet of paper and a simple pencil. Lay it on a hard surface. Stand with your feet on this sheet and circle the outline of the foot with a pencil. Now carefully examine it to determine visually how correct the structure of your feet is.

Pay attention to the big toe. Perfect toe straight, it is more than other toes. The rest of the toes are directed toward the thumb. Pay attention to the foot. It should not have bumps or bumps.

Look at the circumference of the heels. It should be round, uniform, without bumps and cavities. The heels themselves should mirror each other. Pay attention to the arch of the feet and the magnitude of their rise. If the arch of the foot is too low, you should check with the orthopedic surgeon - it may be flat feet.

Foot defects

If, when examining the forms of the foot, you find defects in it, you need to consult a doctor. The causes of flatfoot may be genetic changes, it is difficult to fix. But if you pay attention to the irregular shape of the foot as a child, you can still fix it. In childhood, the bones are still very soft, brittle, so you can deal with defects through exercise, special orthopedic forms for the foot.

Some areas of the foot are most vulnerable. For example, the deformation of the first toe (namely, the tarsus joint). It may be a bone of the heel, as well as fingers in the form of a hammer.

Orthopedic appliances will help to cope with this. It is only necessary to consult with a traumatologist or orthopedist at least once a year in order to avoid further development of foot deformities.

[21], [22], [23]

Timely treatment of legs

If you consult a doctor in time for help, you can correct the deformity of the foot at its initial stage, when a person is not even aware of the abnormal development. Over time, if you do not pay attention to the abnormal development of the foot, the situation will be aggravated under the pressure of mechanical factors - walking, friction, pressure, increased loads.

Therefore, you should always pay attention to the most seemingly minor changes in the structure of the foot. For example, a lump on the heel, hair loss on the legs, a bone on the foot that grows or hurts, even corns that were not previously observed. And immediately consult a doctor about foot health.