Joints unite human skeletal bones into a single whole. More than one hundred and eighty such nodal connections help people to perform various actions. Together with ligaments and bones, they are a well-coordinated system of the motor apparatus. Joints are comparable to hinges. Their task is to provide smooth, or softening action, due to shock-absorbing properties. If they are absent, friction will occur at the joints, gradually leading to the destruction of bone tissue, and this is very painful and dangerous.
In the human body, the joints play the most important role. They preserve the functional integrity of the skeleton, set in motion its individual parts, serve as auxiliary elements for the movement of the body in space. In medicine, there is such a thing as the range of motion in the joints. Detailed information about this is provided below.
Human anatomy, structure and function of joints
Joints are nodes for connecting bones, providing the human skeleton with mobility. Any actions are primarily determined by the participation of these elements, so their condition is especially important for the body. The joint is considered a two-layer bag surrounding the junctions of individual parts of the skeleton. Its main functions are to ensure the tightness of the cavity of the node and the production of synovial fluid, which plays a unifying role in the articulation of bones.
The ends of all components of the skeleton in the areas of joints are distinguished by a special shape: one of them has a bulge, and the other has a special recess. The first part is called the articular head, and the concave part is called the fossa. The surfaces of the recesses, as well as the heads, are covered with elastic smooth cartilage, which reduces friction and plays the role of a shock absorber during tremors and shocks during movements.
Specialists use goniometers to establish the functionality of nodal joints. This allows you to identify their condition and prescribe appropriate treatment. It turns out that the range of motion in the joints is measured, in degrees.
Cartilage
Cartilage is made up of connective tissue fibers that are arranged in a matrix. The latter is a substance formed from glycosaminoglycans. The matrix is responsible for nourishing cartilage and repairing damaged fibers. Such a structure may resemble a sponge. For example, at rest, it can absorb fluid, and during movements it squeezes it into the articular cavity, providinggrease.
What limits range of motion?
There are protrusions on the edges of the articular surface or on the bones located near them, limiting the range of motion. For example, the tubercle of the humerus, which is in contact with the beginning of the scapular process, limits the functionality of the hands. Another important element of the joints are ligaments, which are bundles of fibers that hold the bones in a special position. They are attached in such a way that they provide reliable fixation of the components of the ridge and in no way interfere with their movement.
Elasticity of ligaments
The elasticity of the ligaments makes it possible to make movements of different amplitudes without exposing a person to the risk of injury. True, in the case of extreme loads, the fibers are able to detach from the place of attachment and break as well. With age, their elasticity becomes much less. The most flexible are the ligaments of children, which can stretch ten percent of their length. In middle-aged people, they are only five percent elongated. In older people, elasticity becomes almost zero.
Joints cannot function without the muscles that move them. Even though muscle tissues are not part of the junctions, they cannot function without them.
What is the normal range of motion in the joints, many are interested.
Types of joints
There are several types in the human bodyjoints, classified according to the type of revolutions they make. The most mobile are spherical, having a large number of axes of rotation. With their help, movements are carried out with flexion and extension, abduction and bringing parts of the body into the desired position, as well as outward and inward turns and circular rotations. Shoulder joints are an example of such joints.
Ellipsoid perform such functions as extension and flexion, abduction and adduction, circular movements. These include the wrist joint.
Less range of motion is provided by block and cylindrical joints. For example, the knee and ankle joints usually perform only the function of flexion and extension.
Flat joints are presented in anatomy as joints of bones that do not have heads or pits. Such nodal elements make it possible to perform movements in various directions, however, with a small amplitude. Similar joints are located between the bones of the tarsus and in the wrist. Connections of two bones are called simple, three or more - complex. The number of ligaments is inversely proportional to the mobility of the joint. For example, spherical ones are attached with only one bundle.
Special structure of the joints of the spinal column. The movement of the vertebrae is carried out due to the deformation of the intervertebral elastic discs, which not only provide mobility, but also absorb shocks with shocks and concussions. The movement of the column is carried out in three directions: when bending and unbending, turning and tilting to the sides. The joints of the chestlocated at the junction of the ribs with the sternum and spine. They are flat, with little mobility. Moreover, the sternocostal joints are prone to the same complete loss of mobility and overgrowth of cartilage tissues.
Hip range of motion
Flexion within the hip joint can be measured while lying on the back or on a he althy side. The goniometer is attached to the outer surface of the joint. The screw of the device is at the level of the greater trochanter. One jaw runs along the outer femoral surface, and the other - along the side of the body.
The angle of the fold in he althy people is different. Here the subcutaneous fatty tissue, muscles play a role. Therefore, for comparison, the angle of flexion is measured in the other leg. What is the range of motion in the joints?
Bending up to sixty degrees is allowed. In the event that the patient is able to straighten the leg to such an indicator, a hip flexion contracture of 160 ° is indicated. The doctor focuses on the capabilities of the patient. When the flexion reaches one hundred and twenty degrees, then a flexion contracture of the thigh equal to 120 ° is noted. As for the norm of range of motion in the hip joint, it ranges from one hundred and twenty to one hundred and sixty degrees.
Extension within the hip joint is determined when the patient is in a position on the stomach or on a he althy side. The protractor is placed on the outer surface of the trunk and thigh. The range of motion in the joints varies from person to person.each person and directly depends on the degree of elasticity of the ligaments. The angle between the torso and thigh can be one hundred and sixty-five degrees. In order for the measurement to be correct, it is necessary to ensure that the pelvis does not tilt forward or backward. To do this, a he althy leg must be straight. The physician assistant should fix the pelvis. Normal extension-flexion is: 10/0/130 degrees.
Knee range of motion
As part of the flexion measurement, the patient can lie on his back, as well as on his stomach or on his side, depending on the performance of the elements being tested. The goniometer is applied from the outer surface of the legs, the screw is set at the height of the joint space of the joint. Flexion in a he althy knee knot is possible up to forty-five degrees, and extension - up to one hundred and eighty. Normally, this value is 5/0/140 degrees.
In the event that flexion is possible up to sixty degrees, and extension - up to one hundred and fifty-five, a contracture of the knee joint equal to 155 ° should be noted. In this case, the amplitude of movements is noted in the range from 155 to 60. As for he althy knee joints, the indicator in them is from one hundred and eighty to forty-five degrees.
Abduction and adduction in the knee joint is possible with some diseases or after injuries as a result of damage to the ligamentous apparatus.
Forearm area
The range of motion in the shoulder joint is also checked quite often. Normal indicators:
- extension - 35degrees,
- flexion - 95-100 degrees,
- abduction - 90 degrees (scapula fixed),
- adduction - 25-30 degrees,
- pronation and supination with lowered or abducted hand - 90 degrees each.
Prevention of joint diseases
First of all, you need to watch your weight. Bones are not designed for heavy loads. If you do not strengthen them, but destroy them by eating unhe althy food, then all the more they will be damaged. Excess weight provokes diseases of the hip joint and spine. It is necessary, in addition to exercises, to walk a lot. Walking up the steps every day is of great benefit.
It is extremely important to avoid carrying heavy weights, especially when there are prerequisites for the occurrence of joint diseases. It is forbidden to wear high heels. It is not recommended to take pain medication without consulting a doctor.
As you can see, measuring the range of motion in the joints is an important procedure in the treatment of the musculoskeletal system.
