Rotation A type of motion in which one point of a mechanical system, called the center of rotation, remains stationary.
During rotational motion of absolutely rigid bodies, all their points describe circles located in parallel planes. The centers of all circles lie on the same straight line, perpendicular to the planes of the circles.
Axis of rotation
A line in space about which rotation occurs. Also a part of mechanisms that serves to fix rotation in space.
What parts does our body consist of?
The highest point is the head (caput), then the neck - cervix, after which there is the most central part - the body (torso) - truncus, in which there is a thoracic cavity bounded by the costal surfaces and sternum - thorax, as well as the following areas:
- chest area - pectus;
- the lower abdominal area is abdomen;
- the opposite part is the back - dorsum, connected by the spinal column to the pelvic bones - pelvis,
- the upper limbs themselves are membri superiores and the lower ones are membri inferiores.
The most commonly read landmarks are the planes and axes of the human body.
Purpose and shape of body planes
So, to describe the location, three mutually intersecting perpendicular planes (plana) are used. All of them can be mentally guided with a glance through any component of the human body. Highlight:
- Sagittal (arrow) - planum sagittalia, which translated from Greek sounds like “an arrow piercing the human body.” This plane runs in the front-to-back direction and is located vertically.
- Frontal (frontal) - planum ftontalia, which is parallel to the forehead and perpendicular to the first plane.
- Horizontal (planum horizontalia) perpendicular to the first two above-mentioned planes.
In fact, you can draw as many such planes as you like. So, for example, the vertically located sagittal divides our body into right and left halves and represents the so-called median plane - planum medianum. What else is included in the concept of plane and axis of the human body?
Physical education for everyone: for children and adults
The science of the laws of mechanical motion in living systems (bodies) is called biomechanics. For the correct and justified use of physical therapy and the treatment of patients, an understanding of certain patterns of human movements is necessary.
Body center of gravity
When a body rests on a support (or is suspended from it), the force of gravity presses it against the support (or lifts it away from the suspension). The impact of the body on the support at rest causes resistance from the latter, directed towards the opposite side. By the magnitude of the resistance (reaction) of the support, the magnitude of the body’s action on the support is judged. This quantity is the mass of the body or the force of its gravity.
In relation to the human body, a distinction is made between the general center of gravity (center of mass) for the entire body and the centers of gravity for its individual links (parts). The general center of gravity of a normally physically developed person is in the pelvic region approximately at the level of the second sacral vertebra and is not a strictly fixed point. Even with a calm body position, the overall center of gravity moves constantly within 5-10 mm. When changing posture or movements of body parts, its vibrations can be more significant.
Taking into account the location and movement of the general center of gravity is important for assessing the state of balance of the body. A body is in equilibrium when all the forces acting on it are balanced. To determine balance, it is important to determine the projection of the general center of gravity onto the support area. To do this, find the line of gravity - an imaginary vertical line passing through the center of gravity of the body to the area of support.
The stability (stability) of the body's balance on a support is determined by three factors: the size of the support area, the height of the center of gravity from the supporting surface and the location of the projection of the general center of gravity onto the support area. The lower the center of gravity is and the closer to the center of the support area the line of gravity runs, the more stable the balance. The support area means the area enclosed between the extreme points of the supporting surfaces of the body, that is, the area of the supporting surfaces themselves and the area of the space between them.
Consequently, the support area can be changed in size and shape, including when using support aids. In a normal vertical position of the body, the line of gravity passes in close proximity to the center of the support area (between the feet, 30 - 50 mm anterior to the axis of the ankle joints). A body maintains balance if its line of gravity passes through the area of support. If the line of gravity goes beyond its limits, then the balance is disturbed and the body falls (overturns, moves).
There are two types of early human weight: stable and unstable. Stable balance is one in which the overall center of gravity is located below the support area (for example, hanging on straight arms). An unstable balance is one in which the overall center of gravity of the body is located above the area of support (for example, standing on one leg). In practice, limitedly stable equilibrium is more common, in which stability is maintained only within certain limits of body deflection as long as the line of gravity passes through the area of support.
A person is able to maintain balance and restore it in cases of disturbance by any forces that disturb the balance. This is achieved by the targeted use of muscle movements. By maintaining a position of balance, a person controls his movements, actively fights the action of forces that violate him, which is fundamentally different from the passive balancing of inanimate bodies.
Planes and axes of motion
To study and record the state of the human body and its parts, it is customary to distinguish between body planes and axes of movement. There are three main planes. The sagittal, or anteroposterior (imaginary) plane divides the human body or any part of it into left and right halves (sections), and the sagittal plane passing through the middle of the body is called the median plane. The horizontal plane crosses the body transversely, dividing it into the head (cranial) and caudal (caudal) sections.
A horizontal plane drawn on any limb divides it into proximal (closer to the body) and distal (further from the body) sections. The frontal (parallel to the surface of the forehead) plane divides the body or its parts into anterior (ventral) and posterior (dorsal) sections. All three planes are perpendicular to each other. Any other plane can only be intermediate in relation to the mentioned planes.
All three planes, when intersecting each other, form lines called axes of rotation. When the sagittal and horizontal planes intersect, a sagittal axis is formed, and movement around this axis occurs in the frontal plane. When the frontal and horizontal planes intersect, a transverse axis is formed. Movement around this axis is carried out in the sagittal plane. When the sagittal and frontal planes intersect, a vertical axis is formed. Movement around a vertical axis occurs in a horizontal plane.
Biomechanics considers the human movement apparatus as controlled biokinetic chains, consisting of links interconnected by joints and muscles attached to them. Together they constitute a biomechanism capable of performing specified movements. In a biokinetic chain, movements can be maintained in all joints, only in part of them, or these can be movements of all links as a whole. Biokinetic chains can be open or closed (with connected end links) and therefore have different properties.
Thus, a closed biokinetic chain does not have a free end link, and isolated movements in only one joint are impossible. The main form of movement in the joints is rotation (angular movement). The maximum number of possible axes of movement in one joint is three, and they correspond to three degrees of freedom of movement.
There are joints with one, two and three degrees of freedom of movement. For example, uniaxial joints are the knee, interphalangeal joints of the fingers, biaxial - wrist joints, triaxial - shoulder and hip joints: Movement in the joint around the transverse axis is usually called flexion and extension, around the sagittal - abduction (outward) and adduction (towards the median plane), around the vertical - rotation, or rotation (turning inward and outward). Movement around the longitudinal axis of a limb or segment is also called pronation (inward rotation) and supination (outward rotation). In some joints, circular movements are also possible - alternate intersection of all axes of rotation, in which the free end of the link describes a circle (for example, shoulder, hip, wrist joints).
In the connection of two bone links through a joint (biokinetic pair), the possibilities of movement are determined by the structure of the joint, the effects of the muscles, and the limiting action of the capsule and ligaments of the joint. The amount of mobility in the joints varies among people of different ages and genders, and is associated with individual characteristics and the functional state of the nervous system. In all bone joints, women have, on average, greater mobility than men; among young people more than among older people. With diseases and injuries, mobility in the joints can sharply decrease.
Measuring joint movements
Rotation angles are measured using measuring instruments. The simplest of them is called a protractor, or goniometer; it consists of a protractor with a 180° scale connected to two branches. One of the branches is movable. When measuring, the axis of the protractor is aligned with the axis of the joint, and the branches are placed along the axis of the articulating proximal and distal segments. For continuity and comparability of measurement results and to eliminate errors, the same measurement techniques are required. The angle of maximum extension - flexion of a joint in one plane is called the range of motion.
When measuring movements in the shoulder joint, 0° is taken as the initial value with the arm lowered and the jaws of the protractor closed. When measuring movements in the elbow, wrist, hip and knee joints, 180° is taken as the initial value. Measurements in the ankle joint are usually taken from the initial value of 90°.
Movements of the body in the sagittal, frontal and horizontal planes - tilts, turns, rotations - are carried out thanks to movable joints between the vertebrae. The mobility between them is small, but in total it turns out to be significant. The cervical and lumbar spine are the most mobile, the thoracic spine less so. The following movements of the body are possible: flexion and extension (bending forward and extending backward), bending to the sides (right and left), rotation around a vertical axis (turning right and left) and circular movements.
The starting position (IP) for measuring movements in the joints of the cervical spine is sitting on a chair with the torso and head straightened, the measurement is carried out according to the position of the head. Movements in the thoracic and lumbar regions are measured in a standing position with legs slightly apart and arms hanging freely along the line of the spinous processes.
When measuring rotation in the lumbar region, it is necessary to fix the pelvis, having first seated the patient “astride” on the seat of a chair. The movements of the spine are determined both in degrees (which is more difficult) and visually based on the maximum movements of various sections.
In the cervical spine, flexion normally occurs until the chin touches the sternum, extension until the back of the head is horizontal, bends to the sides until the auricle touches the shoulder girdle, and with maximum rotation, the chin touches the acromion. A trained adult, when bending forward, can touch the floor with his fingertips without bending the knee joints; when bending to the side, the fingertips can touch, sliding along the outer surface of the thigh, the corresponding knee joint.
The normal range of motion in the cervical spine is considered to be: extension 70°, flexion 60°, lateral rotation 75°, lateral bending 45°. The lateral tilts in the thoracic and lumbar regions together amount to 50°. The total amplitude of flexion and extension in the lumbar spine reaches 80°. The total movements of the entire spinal column are possible within the following limits: up to 160° - flexion, up to 145° - extension, total amplitude of movement in the frontal plane - up to 165° and rotations in each direction - up to 120°.
Movement levers
In mechanics, a lever is any inflexible stick that rotates around one point (called the support) when a force is applied to it and some resistance or gravity is overcome. From a mechanical point of view, each segment (link) of the movement apparatus is considered as a lever, the supporting point of which is the articulating section of the link.
The various properties of levers are determined by the relative position of the fulcrum, the points of application of force and resistance of the lever. Levers are of the 1st and 2nd kind. A lever of the 1st kind is characterized by the fact that both forces are directed in one direction, and the fulcrum (axis of rotation) is located between the points of application of the forces. In a second-class lever, force and resistance have different directions, and their points of application are located on one side of the axis of rotation. An example of lever 2 would be a toe raise.
The balance of the lever depends on the length of the arms (the distances between the points of application of force and support), force and resistance and their magnitudes. The longer the lever arm, the less force is needed to maintain its balance. The shorter the arm, the greater the magnitude of the force should be.
Consequently, levers with a larger force arm than resistance are devices for gaining strength, and those with a smaller force arm are devices for gaining distance (in speed and amplitude of movement) by increasing force. For example, the point of application of force (traction of the biceps brachii muscle) is located at a distance of 2 cm from the axis of rotation, and the load held in the hand is 25 cm. To lift such a load, the force of the biceps muscle is required, more than 10 times the mass of the load.
The effect of a muscle's work largely depends on the angle at which it acts on the bone lever. Only pulling at a 90° angle to the lever ensures that all muscle effort is converted into rotational force. But in humans, most of the muscles of the limbs are located along the bone segments at an acute angle and the force of the contracting muscle is divided into two forces - one of them is directed parallel to the longitudinal axis of the segment and causes it to be pressed against the adjacent segment (sometimes pulling), the other produces useful work - rotation of the segment around axis (rotating part of the force).
Stands, hangs, walking, running, squats, jumping, jumping from the point of view of biomechanics
Supports refer to body positions with unstable balance. The most typical is the prone position. The body is straightened and occupies an inclined position, the head is held straight, the cervical spine is in a state of slight extension. The upper limbs are straightened, located almost at right angles to the body and in contact with the supporting surface. The lower limbs are also straightened, but are at an acute angle to the supporting surface. All parts of the body form a closed kinematic chain. The degree of stability of balance is relatively high, since the support area is significant, and the height of the overall center of gravity is small (30-35 cm).
Therefore, in this position it is possible to perform various movements with the movement of body parts without disturbing balance.
Body positions with upper support include various hanging positions. These provisions are stable. The simplest of them is a “clean” hang with straight arms. The human body occupies a straightened vertical position. The arms are raised up, straightened and fixed to the apparatus. The force of gravity tends to stretch the body. It is counteracted by the force of muscle traction. The work of the movement apparatus in this position is complex, since it occurs under unusual conditions for the body. Hanging exercises are considered strength exercises. If leg support is used in a hanging position (mixed hanging), body weight is more evenly distributed among muscle groups and breathing function is not impaired. Mixed hangs are widely used in physical therapy.
Walking is a normal human motor activity; it is a constant alternating activity of the legs. When one leg, resting on the ground, serves to support and subsequently push away the body (the support phase of one leg), the other, raised and hanging in the air, moves forward (the swing or swing phase of the other leg). Each leg sequentially goes through both phases - support and transfer. Two steps make up a cycle.
Running is a cyclic step movement, a complex reflex motor act that requires the participation of all the skeletal muscles of the body, significant tension in the nervous system and sufficient physical training of a person. It can be dosed according to speed, duration, step width, etc.
Squats are exercises performed primarily by working the muscles of the lower extremities. The feet can rest on the support area with the entire plantar surface or only on the heads of the metatarsal bones and toes. Exercises can be facilitated by supporting the hands on the front surfaces of the thighs, supporting them with some object. The amount of load is dosed by the depth of the squats, tempo and number of repetitions. Exercises can be complicated and burdened by the load on free hands.
Jumps are characterized by free flight of the body in the air as a result of repulsion from the supporting surface. The main work is performed by the muscles of the lower extremities, auxiliary - by the muscles of the trunk and upper extremities. The exercise is ensured by the simultaneous contraction of large muscle groups of the lower extremities, a large range of motion in the large joints of the legs and shoulder joints.
Jumping jacks are simple jumps in place.
The main load when jumping falls on the flexors of the foot. In the ankle joint, when jumping, the maximum range of motion is used. The muscles of the hip and knee joints play a supporting role. Movements in these joints occur with a small amplitude. "Basic methods of research and assessment of human physical development —|||— The concept of fatigue, overwork, overexertion and overtraining"
Organ designation
To designate organs relative to a horizontal plane, concepts such as:
- Cranial – upper (from the side of the skull, if translated literally).
- Caudal - lower (from the Latin word cauda - tail).
- Dorsal - rear (dorsum - back).
To correctly designate parts of the body located laterally, the term lateral (lateralis) is used, that is, if these named areas are located at any distance from the midline. And those organs or areas located in the zone of the same median shooting (sagitial) region are called: medial (medialis). This is included in the main planes and axes of the human body.
The writing is on the wall
So, all exercises in plane training are divided into the following types:
Horizontal presses are exercises that are performed in the sagittal plane. When they are performed, the shoulder flexes and the forearm extends. Simply put, they all resemble the bench press. Vertical presses are exercises that are performed in the frontal plane. When they are performed, the shoulder moves from a horizontal or lowered position upward in the frontal plane. An example is abductions and dumbbell presses while standing (sitting). Horizontal rows are exercises, just like horizontal presses, performed in the sagittal plane, but inverse to them, that is, when performing these movements, the shoulder extends and the forearm flexes. A classic example is the wide-grip bent-over barbell row. Vertical rows are similar to vertical presses: they are performed in the frontal plane, when they are performed, the shoulder is adducted and the forearm is flexed. The most recognizable exercises here are wide-grip pull-ups and all their derivatives. Knee-dominant exercises - in this type, we, to put it simply, move to the “bottom” of the body. They are performed in the sagittal plane; when they are performed, the lower leg and thigh are extended (the leg is straightened at the knee). An example is all types of squats. Pelvic-dominant exercises are also performed in the sagittal plane, when they are performed, the lower leg is extended, but unlike knee-dominant exercises, the main load when performing them falls on the back of the thigh. These exercises include deadlifts and hyperextensions. HPN exercises (rotating the shoulder outward) - when performed, the shoulder is supinated, the plane of execution depends on the position of the humerus. Classic exercises - standing dumbbell (weight) chest lifts, dumbbell (weight) jerk from the floor. Exercises that train the core - in the planar training system, the core refers to the muscles that transmit force from the upper part of the body (chest, shoulder girdle, arms) to the lower part (pelvis, legs) and vice versa. When talking about core muscles, they give the example of nunchucks (I think the term needs no explanation). So, the chain connecting both halves of this weapon works in a similar way to our core muscles. Its strength (and in our body, by analogy, muscle strength) determines the speed and magnitude of the transmitting force from one part to another. Thus, the core muscles are the muscles that stabilize the spine, pelvis, and shoulder joints. An example of exercises is “plank”, twisting, hyperextension on a fitball. Auxiliary exercises – exercises that develop grip (barbell curls “biceps”), triceps (some variants of the French press), calf muscles (calf raises).
Frequently used adjectives
To determine the correct characteristics of the areas that make up the upper or lower limb, adjectives such as those located closer to the body, that is, proximal (proximalis) and, accordingly, distal (distalis), are used. This is required to designate the points most distant from the body.
When describing, it is possible to use such definitions as right (dexter), for example, right hand, left (sinister), left kidney.
Depending on the size, when compared with something, a large (major), for example, an organ, or a small, insignificant size (minor) is distinguished.
To designate depending on the depth of location or lesion, such a concept as superficial (siperficialis) and deep (profundus) has been introduced. What are the planes and axes of the human body?
What movements are performed in the sagittal plane around the frontal axis?
Biomechanics and safety Bobylev V., Zheldakov D.
In order to technically perform exercises competently, get the maximum effect from training and, ultimately, avoid injury, it is necessary to understand the biomechanical foundations of movements.
Being in three-dimensional space means the presence of three planes.
Bend your leg at the hip while standing and then lying down. The movement is the same, but in what plane is it performed? In order to avoid confusion with the description of movements, scientists have come up with a simple solution - to consider all movements relative to the human body. Therefore, now it doesn’t matter to us whether a person is standing, lying, running or falling on his side, the planes do not change.
“Anatomical position” was chosen as the starting point for describing movements. Why her? All processes in the body (breathing, blood circulation, metabolism) occur most efficiently in it. A person takes an “anatomical position” when he stands with his back straight, his shoulder blades brought towards his spine and his palms turned forward.
All movements are performed by moving one or more bones relative to each other at the points of their connection - joints. The specific shape of the joint allows us to carry out movements in one or more planes.
To perform movements most accurately, you need to know that movement in the joints is performed around a certain axis.
The axis of rotation of the movement is always perpendicular to the plane of movement. And even if you lie on the floor, or find yourself in a position that cannot be described at all, adduction will not become rotation or abduction. And all because movements are considered relative to the human body, and not to the earth or any object.
Moving bones relative to each other is possible because our muscles have the ability to contract. Depending on how the muscle contracts, we produce movements of a different nature. Let’s use the example of a simple exercise “Bending the arms at the elbow joints using additional weights” to see how this happens. The positive phase of the movement, in which the arm flexes at the elbow joint, is accompanied by contraction, with a simultaneous decrease in the length of the biceps brachii muscle. This type of contraction is called concentric.
If the body or limb moves in space, then this is a dynamic mode. All types of abbreviations listed apply to this mode.
In order to ensure the safety of the cervical spine, do not allow excessive tilting and, especially, throwing your head back.
More information about the biomechanical parameters of the simulator
The ability to adjust the position of the blocks (rollers) in accordance with the width of your shoulder or hip joints makes the exercises performed as close as possible to natural movements. The correctly selected distance between the blocks optimally matches the forces of gravity and muscle resistance in any phase of movement. This design feature of the simulator (protected by two patents) sharply reduces the risk of injury to working joints and muscles.
In addition, the presence of blocks adds additional instability, causing stabilizers, such as the abdominal and back muscles, to become more active. Thus, the energy intensity of the exercises performed increases significantly.
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FTL for the amateur:
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Source
Varieties of axes of the human body
The three anatomical planes described above correspond to three anatomical axes.
Therefore, the frontal axis of the same name as the frontal plane is located parallel to it and is horizontally directed. The movements that are possible around are presented in the form of flexion (flexio) and extension (extensio), most often of the limbs, but possibly of the torso itself.
The sagittal axis, accordingly, is located parallel to the sagittal plane and allows adduction (adductio) and abduction (abductio). Movement around the third axis (vertical) allows for movements in a circle (rotatio et circumductio), with the formation of a so-called “cone” in the air, the apex of which is represented by a joint. The diagram of axes and planes in the human body will be presented below.
Axes of rotation
The axis of rotation can be fixed, connected to the holding body, and free, when there is no external holding body (in free flight).
The axis of rotation is often a material body external to a person, fixed motionless. A gymnast, for example, holds onto the bar of the crossbar directly and has direct contact with it. The line passing through the suspension points of the gymnastic rings is also a fixed external axis; The gymnast is no longer connected to it directly, but through the ropes of the rings. But in both cases these are fixed external axes.
When the links of the human body rotate in the joints, the axis of rotation always passes inside the body. One link is connected to another articular-ligamentous apparatus and muscles passing through the joint. There are fixed internal axes here.
When the athlete's entire body rotates in free flight, the axis of rotation passes through the body's center of gravity, but is not connected to any external body. It moves with the GCT along any trajectory. The axis of rotation of the human body, which does not have support, is free.
The rotational motion of a rigid body from the kinematic side is characterized by the location of the axis of rotation. Their linear velocities and accelerations depend on the distance of each point of the body to the axis of rotation (radius of rotation); they are directly proportional to the radius of rotation (v=wr;
a=er).
Fixed axes of rotation (external and internal) characterize the rotational motion of a rigid body also from the dynamic side. They are connected to a holding body, which causes a curvature of the trajectory of the points and changes the direction of their velocities.
1.3. Interaction of rotating and holding bodies
Centripetal force is a measure of the action of a holding body on a rotating one. It causes a curvature of the trajectory depending on the mass, speed and radius of rotation. Centrifugal force (inertia) - the resistance of a rotating body to the curvature of its trajectory - is applied to the holding body. Both forces are applied to different bodies, and therefore do not balance each other.
The holding body acts on the rotating body with a centripetal force,
which is directed perpendicular to the movement of the central body towards the concavity of the trajectory (center of curvature). Centripetal force is a measure of the action of a holding body on a rotating body; it is applied to the rotating body at the point of connection with the holding body. A rotating body receives centripetal acceleration caused by the action of centripetal force.
In turn, the rotating body exerts unbalanced resistance with its inertial force, directed directly opposite to the centripetal force and applied to the holding body. This is centrifugal force -
inertial force of a rotating body.
The centrifugal force of the entire body is equal to the sum of the centrifugal forces of all its particles. The centripetal force is greater if the rotating body has more mass, the turn is steeper, and especially if the rotation speed is high (quadratic dependence).
In the human body, during rotational motion, each link located closer to the axis of rotation plays the role of a holding body for the neighboring link located further from the axis of rotation.
When rotating in free flight, there is no external holding body, and there is no external centripetal force. All internal forces in the body are mutually balanced and do not affect the trajectory of the central gravity. But they hold the particles of the body near the axis of rotation. The centrifugal forces of the particles of one half of the body serve as centripetal forces for the particles of the other half, located on the other side of the axis.
In a biomechanical system, during rotation, numerous centripetal and centrifugal forces of parts of the body, its organs and tissues (including liquid ones) act. The result is deformation and stress. When centripetal accelerations are greater, tensions in tissues transmitting loads (muscles, joint-ligamentous apparatus) and deformations increase.
As Fcs , body parts move closer to the central center of gravity, and the radius of rotation (grouping) decreases. Fcs decreases, the movement occurs in the opposite direction (ungrouped and e). Here, the rotational movement of each link of the body is joined by a translational one along the radius: the approach of parts of the body to the axis and moving away from it, i.e. shortening and lengthening the radius of rotation. Changing the radius of rotation turns a rotational (simple) motion into a compound motion around an axis.
Such movement around an axis with a change in the radius of rotation, in fact, occurs not only in flight, but in almost all human movements. The kinematic chains of the limbs are shortened and lengthened (bending and unbending). And in each joint, strictly speaking, there is no constant geometric axis of rotation, since the shape of the articular surfaces is not geometrically correct. And under heavy loads, hyaline articular cartilage also becomes deformed. Therefore, even in each joint the movement is not purely rotational; the trajectories of the link points have variable curvature.
In many cases, changes in the radius of rotation, as small as possible, are possible. neglect. But at the same time, in most movements, changes in the radius of rotation are large and play a significant role. Here it is no longer possible to neglect them and reduce complex motion around an axis to simple rotational motion. On the contrary, it is necessary to identify how the movement around the axis changes with a change in the radius.
Consequently, in the human body, centripetal forces directed towards its axis of rotation can, by changing posture, reduce the radius of rotation (grouping), then simple movement (rotational) turns into complex (simultaneously around the axis and along the radius),
Classification of conducted lines
To indicate the border of an organ or joint, it is also possible to use imaginary lines (anterior and posterior midlines - linea mediana anterior et linea mediana posterior). So the linea mediana anterior limits the right and left parts of the surface of the body, passing through the middle of the front surface of the body. linea mediana posterior also separates these halves, but only from the rear surface. And it is carried out through the tops of the spinous vertebral processes.
Anatomical nomenclature (the axes and planes of the human body) has been studied for a long time.
Along both edges of the sternum there are, respectively, the right and left sternal lines (linea sternalis dextra et linea sternalis sinistra). They can still be carried out a lot, for example, through the middle of the collarbone. These lines will then be called the left or right midclavicular line. The anterior, posterior and middle axillary zones are also distinguished. Their differences lie only in the area through which one or another line passes, be it the edge of the armpit or the middle (linea axillaris anterior, posterior et mediana).
It originates from the scapular angle and runs through the scapular line (linea scapularis).
On both sides of the spinal column, along its costal-transverse composite surfaces, there are paravertebral or spinal axes (linea paravertebralis).
Anatomical terminology
When studying human anatomy, the concepts of body parts, planes and axes are used to indicate the position of the body and organs in space and their location relative to each other.
The initial position is taken to be the natural vertical position of the human body with arms hanging along the body, palms facing forward and thumbs outwards. The human body has the following parts: head, neck, torso, upper and lower limbs.
The head is divided into two sections - facial and brain.
Upper limb – upper limb belt and free upper limb.
Lower limb – belt of the lower limb; free lower limb.
There are a number of areas on the body: chest, back, abdomen, pelvis.
The human body is built on the principle of bilateral symmetry and is divided into two halves - right and left.
When describing parts of the body and the position of individual organs, three mutually perpendicular planes are used:
- sagittal;
— frontal;
— horizontal.
The sagittal plane (from the Latin Soqitta - arrow) - runs in the anteroposterior direction and divides the human body into right and left parts.
The sagittal plane passing through the middle of the body is called the median or medial plane.
The frontal plane ((from Latin frons - forehead) - is parallel to the plane of the forehead and divides the human body into the front and back.
The horizontal plane runs perpendicular to the frontal and sagittal planes and separates the upper parts of the body from the lower ones. These planes can be drawn through any point of the human body; the number of planes can be arbitrary.
To indicate the position of organs and parts of the body, the following anatomical terms are used:
- medial (medialis), if the organ lies closer to the median plane;
- lateral (lateralis), if the organ is located further from it;
- internal (internus), i.e. lying inside;
- external ( externus), outward, when talking about organs located inside the cavity (part of the body), or outside it;
— deep (profundus) – lying deeper;
- surface (superficialis) - lying on the surface - to determine the position of organs, located at different depths;
- cranial (cranialis) - the surface (or edge) of the organ facing the head;
- caudal (caudalis) - facing the pelvis.
When describing limbs, the following terminology is used:
- proximal ( praximalis) - lying closer to the body;
- distal ( distalis) - distant from it.
To determine the boundaries of organs (heart, lungs, pleura, etc.) vertical lines are conventionally drawn on the surface of the body, oriented along the human body.
— The anterior midline is a transition along the front surface of the body, on the border between its right and left halves.
- Posterior midline - runs along the spinal column, along the tops of the spinous processes of the vertebrae.
- Thoracic line - runs along the edge of the sternum.
- Midclavicular - through the middle of the collarbone.
- Anterior, middle and posterior axillary lines - pass respectively from the anterior fold, middle, part and posterior fold of the axillary fossa.
- Scapular line - passes through the lower angle of the scapula.
- Paravertebral line - along the spinal column through the costotransverse joints.
To determine the direction of movement in joints or the orientation of organs, rotation axes are conventionally used - lines forming from the intersection of planes:
- vertical;
- sagittal (antero-posterior);
- frontal (transverse) axis.
— Vertical axis – formed at the intersection of the sagittal and frontal planes. When rotating around a vertical axis, movements occur strictly in the horizontal plane.
— Sagittal axis — is formed at the intersection of the horizontal and sagittal planes. When a part of the body rotates around this axis, the movement occurs strictly in the frontal plane.
- Frontal axis - formed at the intersection of the frontal and horizontal planes. Rotation around the frontal axis is carried out in the sagittal plane.
Dividing the abdominal area into zones
How else are axes and planes drawn through the human body distinguished?
As for the abdominal area, its entire surface is evenly divided into nine zones, each of which has its own individual designation. These areas are formed by two horizontal lines. The upper one connects the heads of the tenth pairs of ribs, and the lower one passes through the anterior superior iliac spines. Thus, we find that above the costal line (linea costarum) the region of the epigastrium (epigastrium) is located. And below the guard (linea spinarum) is the hypogastrium zone. The space between them is presented in the form of mesogastrium. In addition to the horizontal ones, there are also two vertical lines. As a result, 9 small areas are formed.
The division into areas, zones, lines of our body is similar and has its own characteristics inherent in a certain area, area or zone, as well as its own individual designation.
On surface
Understanding the three anatomical planes of movement (sagittal, frontal, and horizontal) can help you become aware of your patterns and bodily imbalances, allowing you to move with more intention—both in your yoga practice and off the mat.
Text: Annie Carpenter. Photographer: Rick Cummings. Translation: Maria Romanova
It's important for us yogis to understand how we move—and as we become more aware, we also become more curious and self-aware. I see this evolution in my students all the time. The first spark of insight often becomes a revelation (perhaps a person suddenly realizes that his left hip joint is more rigid than his right). He may soon notice that this makes him prefer to use the right side of his body. He may then find that it causes back pain. With every discovery this student makes about his movements, he becomes more aware, more inquisitive, and ultimately gets to know himself better.
Understanding exactly how your body moves is the key to getting stronger, avoiding injury, and feeling more balanced, grounded, and yes, happy. And a great way to help you do this is to look at movement through the lens of the three anatomical planes.
Organ systems in the human body
The human body has organ systems that are assigned certain functions:
- Support and movement. The skeletal system is responsible for all this.
- Processing of food with absorption of nutrients. The digestive organs are created for these purposes.
- Gas exchange - oxygen enters and carbon dioxide leaves. This is provided by the respiratory organs.
- Release from metabolic products. The urinary organs are responsible for this.
- Reproduction. The genitals respond.
- Transport of nutrients to tissues and organs. This is the task of the circulatory system.
- Hormonal regulation of the body's vital functions. The endocrine system is capable of this.
- Balancing activities and adapting the body. This is provided by the nervous system.
- Perception of information from the external and internal environment. This requires sense organs.
We looked at what planes and axes of the human body there are in anatomy.
Korolev E. V. Axes and planes
To accurately describe the relative position of parts of the human body, anatomy has adopted its own terminology.
A person is considered to be standing upright (vertically) with his arms down. Hands are turned palms forward (thumbs pointing to the sides).
As in a conventional rectangular coordinate system, three mutually perpendicular axes and three planes are introduced. Of these three planes, one is horizontal and two are vertical.
The horizontal plane is called horizontal or transverse . It divides the human body into upper and lower halves.
You need to understand that this plane can be drawn across the body at any level. There is no designated point through which it must pass. Therefore, there is an infinite number of horizontal planes. The same applies to other planes.
Of the two vertical planes, one divides the human body into the front and back. This plane is called frontal . It is approximately parallel to the surface of the forehead (frontalis - frontal). Another plane divides the human body into right and left halves. This plane is called the sagittal (sagitta - arrow; apparently, you need to imagine an arrow sticking straight out of your chest). As already mentioned, these planes can be drawn through the body anywhere, so there are an infinite number of them. But there is also a special place for the sagittal plane. You can place it exactly in the middle of the body - through the sagittal (what a coincidence!) suture connecting the two parietal bones of the skull. In this case, the sagittal plane is called median or median . Often it is the median plane that is called the sagittal plane.
These planes intersect in pairs, forming three axes. Again, these axes can be drawn anywhere through the human body.
The axis formed by the intersection of the horizontal (transverse) plane with the frontal is called transverse , the intersection of the horizontal plane with the sagittal - sagittal or anteroposterior axis, and the intersection of the sagittal plane with the frontal - vertical or longitudinal axis.
Now we list the terms that define the position of individual organs or structures or parts of organs.
The part of the organ facing the anterior end of the body is called anterior , and the part facing the rear is called posterior. ventral (venter - belly) and dorsal are also used .
The part of the organ facing the head is called superior (superior), and the part facing the pelvis is called inferior (inferior). Terms accepted in the anatomy of four-legged animals are also used as synonyms: cranial (cranialis - cranial) and caudal (caudalis - caudal). These two terms are used only in relation to the torso and neck.
The part of the organ located closer to the median (median) plane is called internal or medial (medialis), and the opposite part is called external or lateral (lateralis).
For limbs there are special terms that denote the proximity of part of the limb to the torso. The closer parts are called proximal (proximalis), and the more distant parts are called distal (distalis).
The directions in the body are designated accordingly:
- upward, or cranially - downwards, or caudally
- anteriorly, or ventrally - posteriorly, or dorsally
- inwards, or medially - outwards, or laterally
- proximal - distal