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1 STATIC, mechanics section, the subject of which is material bodies, which are at rest when acted upon external forces. IN in a broad sense words statics is the theory of equilibrium of any solid, liquid or gaseous body. In a narrower sense this term relates to the study of balance solids, as well as non-stretchable flexible bodies of cables, belts and chains. The equilibrium of deforming solids is considered in the theory of elasticity, and the equilibrium of liquids and gases in hydroaeromechanics. See HYDROAEROMECHANICS. Historical information. Statics is the oldest branch of mechanics; some of its principles were already known to the ancient Egyptians and Babylonians, as evidenced by the pyramids and temples they built. Among the first creators of theoretical statics was Archimedes (c. BC), who developed the theory of the lever and formulated the fundamental law of hydrostatics. The founder of modern statics was the Dutchman S. Stevin (), who in 1586 formulated the law of addition of forces, or the parallelogram rule, and applied it to solve a number of problems. Basic laws. The laws of statics follow from general laws speakers like special case, when the velocities of solid bodies tend to zero, but historical reasons and pedagogical considerations, statics is often presented independently of dynamics, building it on the following postulated laws and principles: a) the law of addition of forces, b) the principle of equilibrium and c) the principle of action and reaction. In the case of solids (more precisely, ideally solid bodies that do not deform under the influence of forces), another principle is introduced, based on the definition of a rigid body. This is the principle of force transfer: the state of a solid body does not change when the point of application of force moves along the line of its action. Force as a vector. In statics, force can be considered as a pulling or pushing force that has a certain direction, magnitude and point of application. WITH mathematical point In terms of vision, it is a vector, and therefore it can be represented by a directed segment of a straight line, the length of which is proportional to the magnitude of the force. (Vector quantities, unlike other quantities that do not have a direction, are denoted by bold letters.) Parallelogram of forces. Let's consider a body (Fig. 1,a), which is acted upon by forces F 1 and F 2, applied at point O and represented in the figure by directed segments OA and OB. As experience shows, the action of the forces F 1 and F 2 is equivalent to one force R, represented by the segment OC. The magnitude of the force R is equal to the length of the diagonal of the parallelogram constructed on the vectors OA and OB as its sides; its direction is shown in Fig. 1, a. The force R is called the resultant of the forces F 1 and F 2. Mathematically this is written in the form R = F 1 + F 2, where addition is understood in geometric sense words mentioned above. This is the first law of statics, called the rule of parallelogram of forces.

2 Resultant force. Instead of constructing a parallelogram OACB, to determine the direction and magnitude of the resultant R, you can construct a triangle OAC by moving the vector F 2 parallel to itself until it aligns starting point (former point O) with the end (point A) of the vector OA. The closing side of the triangle OAC will obviously have the same magnitude and the same direction as the vector R (Fig. 1, b). This method of finding the resultant can be generalized to a system of many forces F 1, F 2,..., F n applied at the same point O of the body under consideration. So, if the system consists of four forces (Fig. 1, c), then you can find the resultant of the forces F 1 and F 2, add it with the force F 3, then add the new resultant with the force F 4 and as a result get the total resultant R. The resultant R found in this way graphical construction, is represented by the closing side of the polygon of forces OABCD (Fig. 1, d). The above definition of the resultant can be generalized to a system of forces F 1, F 2,..., F n applied at points O 1, O 2,..., O n of a rigid body. A point O, called the reduction point, is selected, and a system of parallel transferred forces equal in magnitude and direction to the forces F 1, F 2,..., F n is constructed at it. The resultant R of these parallel transferred vectors, i.e. the vector represented by the closing side of the force polygon is called the resultant of the forces acting on the body (Fig. 2). It is clear that the vector R does not depend on the chosen reduction point. If the value of the vector R (segment ON) is not zero, then the body cannot be at rest: in accordance with Newton’s law, any body on which a force acts must move with acceleration. Thus, a body can be in a state of equilibrium only if the resultant of all forces applied to it is equal to zero. However, this necessary condition cannot be considered sufficient: a body can move when the resultant of all forces applied to it is equal to zero.

3 As a simple, but important example To explain this, consider a thin rigid rod of length l, the weight of which is negligible compared to the magnitude of the forces applied to it. Let two forces F and F act on the rod, applied to its ends, equal in magnitude, but oppositely directed, as shown in Fig. 3, a. In this case, the resultant R is equal to F F = 0, but the rod will not be in a state of equilibrium; obviously, it will rotate around its midpoint O. A system of two equal but oppositely directed forces acting in more than one straight line is a “pair of forces”, which can be characterized by the product of the magnitude of the force F and the “arm” l. The significance of such a work can be shown by the following reasoning, which illustrate the lever rule derived by Archimedes and lead to the conclusion about the condition of rotational equilibrium. Let us consider a light homogeneous rigid rod capable of rotating around an axis at point O, which is acted upon by a force F 1 applied at a distance l 1 from the axis, as shown in Fig. 3, b. Under the influence of force F 1, the rod will rotate around point O. As is easy to see experimentally, rotation of such a rod can be prevented by applying some force F 2 at such a distance l 2 that the equality F 2 l 2 = F 1 l 1 is satisfied.

4 Thus, rotation can be prevented in countless ways. It is only important to choose the force and the point of its application so that the product of the force by the shoulder is equal to F 1 l 1. This is the rule of leverage. It is not difficult to derive the equilibrium conditions for the system. The action of the forces F 1 and F 2 on the axis causes a reaction in the form of a reaction force R applied at point O and directed opposite to the forces F 1 and F 2. According to the law of mechanics about action and reaction, the magnitude of the reaction R is equal to the sum of the forces F 1 + F 2 Therefore, the resultant of all forces acting on the system is equal to F 1 + F 2 + R = 0, so that the necessary equilibrium condition noted above is satisfied. Force F 1 creates a torque acting clockwise, i.e. moment of force F 1 l 1 relative to point O, which is balanced by counterclockwise moment F 2 l 2 of force F 2. Obviously, the condition for equilibrium of a body is equality to zero algebraic sum moments, eliminating the possibility of rotation. If the force F acts on the rod at an angle, as shown in Fig. 4a, then this force can be represented as the sum of two components, one of which (F p), with a value of F cos, acts parallel to the rod and is balanced by the reaction of the support F p, and the other (F n), with a value of F sin, is directed under right angle to the lever. In this case, the torque is equal to Fl sin; it can be balanced by any force that creates an equal torque acting counterclockwise. To make it easier to take into account the signs of moments in cases where a lot of forces act on the body, the moment of force F relative to any point O of the body (Fig. 4,b) can be considered as a vector L equal to vector product r F of the position vector r by force F. Thus, L = r F. It is easy to show that if a rigid body is acted upon by a system of forces applied at points O 1, O 2,..., O n (Fig. 5), then this system can be replaced by the resultant R forces F 1, F 2,..., F n, applied at any point O of the body, and a pair of forces L, the moment of which equal to the sum+ . To verify this, it is enough to mentally apply at point O a system of pairs of equal but oppositely directed forces F 1 and F 1 ; F 2 and F 2 ;...; F n and F n, which obviously will not change the state of the solid.

5 But the force F 1 applied at point O 1 and the force F 1 applied at point O form a pair of forces whose moment relative to point O is equal to r 1 F 1. Similarly, the forces F 2 and F 2 applied at points O 2 and O, respectively, form a pair with the moment r 2 F 2, etc. The total moment L of all such pairs relative to the point O is given by the vector equality L = + . The remaining forces F 1, F 2,..., F n, applied at point O, add up to the resultant R. But the system cannot be in equilibrium if the values ​​of R and L are different from zero. Consequently, the condition for the values ​​R and L to be equal to zero at the same time is a necessary condition balance. It can be shown that it is also sufficient if the body is initially at rest. So, the equilibrium problem comes down to two analytical conditions: R = 0 and L = 0. These two equations represent mathematical notation principle of balance. Theoretical provisions statics are widely used in the analysis of forces acting on structures and structures. In case continuous distribution forces of the sum, which give the resulting moment L and the resultant R, are replaced by integrals and in accordance with conventional methods integral calculus. See also MECHANICS; STRENGTH CALCULATION OF STRUCTURES. LITERATURE Smokotin G.Ya. Course of lectures on statics. Tomsk, 1984 Birger I.A., Mavlyutov R.R. Strength of materials. M., 1986 Babenkov I.S. Fundamentals of statics and resistance of materials. M., 1988

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The action of a pair of forces on a body is characterized by: 1) the magnitude of the moment modulus of the pair, 2) the plane of action, 3) the direction of rotation in this plane. When considering pairs that do not lie in the same plane, all three of these elements will need to be specified to characterize each pair. This can be done if we agree, by analogy with the moment of force, to represent the moment of a couple in an appropriate way, constructed by a vector, namely: we will represent the moment of a couple with a vector m or M, the modulus of which is equal (on the chosen scale) to the modulus of the moment of the couple, i.e. the product of one of its forces on the shoulder, and which is directed perpendicular to the plane of action of the pair in the direction from which the rotation of the pair is seen occurring counterclockwise (Fig. 38).

Rice. 38

As is known, the modulus of the moment of a pair is equal to the moment of one of its forces relative to the point where another force is applied, i.e.; in the direction the vectors of these moments coincide. Hence.

Moment of force about the axis.

To move on to solving statics problems for the case of an arbitrary spatial system of forces, it is also necessary to introduce the concept of the moment of force relative to the axis.

The moment of force about an axis characterizes the rotational effect created by a force tending to rotate a body around a given axis. Consider a rigid body that can rotate around some axis z (Fig. 39).

Fig.39

Let this body be acted upon by a force applied at a point A. Let's draw through the point A plane xy, perpendicular to the z axis, and decompose the force into components: parallel to the z axis, and lying in the xy plane (it is also a projection of the force on the plane xy). Force directed parallel to the axis z, obviously cannot rotate the body around this axis (it only tends to move the body along the axis z). The entire rotational effect created by the force will coincide with the rotational effect of its component. From here we conclude that , where symbol) denotes the moment of force relative to the axis z.

For a force lying in a plane perpendicular to the axis z, the rotational effect is measured by the product of the magnitude of this force and its distance h from the axis. But the same quantity measures the moment of force relative to a point ABOUT, in which the axis z intersects with the plane xat. Hence, or, according to the previous equality, .

As a result we come to the following definition: the moment of a force about an axis is a scalar quantity equal to the moment of projection of this force onto a plane perpendicular to the axis, taken relative to the point of intersection of the axis with the plane.

From the drawing (Fig. 40) it is clear that when calculating the moment, the plane xy can be drawn through any point on the axis z. Thus, to find the moment of force about the axis z(Fig. 40) you need to:

1) draw a plane xy, perpendicular to the axis z (anywhere);

2) project the force onto this plane and calculate the magnitude;

3) lower from the point ABOUT intersection of the axis with the plane perpendicular to the direction and find its length h;

4) calculate the product;

5) determine the sign of the moment.

When calculating moments, the following special cases must be kept in mind:

1) If the force is parallel to the axis, then its moment relative to the axis is zero (since ).

2) If the line of action of the force intersects the axis, then its moment relative to the axis is also zero (since h = 0).

Combining both cases together, we conclude that the moment of a force about an axis is zero if the force and the axis lie in the same plane.

3) If the force is perpendicular to the axis, then its moment relative to the axis is equal to the product of the modulus of the force and the distance between the force and the axis.

Contents of the article

STATICS, a branch of mechanics, the subject of which is material bodies that are at rest under the action of external forces on them. In the broad sense of the word, statics is the theory of equilibrium of any body - solid, liquid or gaseous. In a narrower sense, this term refers to the study of the equilibrium of solid bodies, as well as non-stretchable flexible bodies - cables, belts and chains. The equilibrium of deforming solids is considered in the theory of elasticity, and the equilibrium of liquids and gases is considered in hydroaeromechanics.
Cm. HYDROAEROMECHANICS.

Historical information.

Statics is the oldest section of mechanics; some of its principles were already known to the ancient Egyptians and Babylonians, as evidenced by the pyramids and temples they built. Among the first creators of theoretical statics was Archimedes (c. 287–212 BC), who developed the theory of the lever and formulated the fundamental law of hydrostatics. The founder of modern statics was the Dutchman S. Stevin (1548–1620), who in 1586 formulated the law of addition of forces, or the parallelogram rule, and applied it to solve a number of problems.

Basic laws.

The laws of statics follow from the general laws of dynamics as a special case when the velocities of solid bodies tend to zero, but for historical reasons and pedagogical considerations, statics is often presented independently of dynamics, building it on the following postulated laws and principles: a) the law of addition of forces, b) the principle of balance and c) the principle of action and reaction. In the case of solids (more precisely, ideally solid bodies that do not deform under the influence of forces), another principle is introduced, based on the definition of a rigid body. This is the principle of force transfer: the state of a solid body does not change when the point of application of force moves along the line of its action.

Force as a vector.

In statics, force can be considered as a pulling or pushing force that has a certain direction, magnitude and point of application. From a mathematical point of view, it is a vector, and therefore it can be represented by a directed segment of a straight line, the length of which is proportional to the magnitude of the force. (Vector quantities, unlike other quantities that do not have a direction, are denoted by bold letters.)

Parallelogram of forces.

Consider the body (Fig. 1, A), which is acted upon by forces F 1 and F 2 applied at point O and represented in the figure by directed segments O.A. And O.B.. As experience shows, the action of forces F 1 and F 2 is equivalent to one force R, represented by the segment O.C.. Magnitude of force R equal to the length of the diagonal of a parallelogram built on vectors O.A. And O.B. like its sides; its direction is shown in Fig. 1, A. Strength R called the resultant force F 1 and F 2. Mathematically this is written as R = F 1 + F 2, where addition is understood in the geometric sense of the word indicated above. This is the first law of statics, called the rule of parallelogram of forces.

Resultant force.

Instead of constructing a parallelogram OACB, to determine the direction and magnitude of the resultant R you can construct triangle OAC by moving the vector F 2 parallel to itself until its starting point (former point O) coincides with the end (point A) of the vector O.A.. The trailing side of triangle OAC will obviously have the same magnitude and the same direction as the vector R(Fig. 1, b). This method of finding the resultant can be generalized to a system of many forces F 1 , F 2 ,..., F n applied at the same point O of the body under consideration. So, if the system consists of four forces (Fig. 1, V), then we can find the resultant force F 1 and F 2, fold it with force F 3, then add the new resultant with force F 4 and as a result obtain the full resultant R. Resultant R, found by such a graphical construction, is represented by the closing side of the polygon of forces OABCD (Fig. 1, G).

The above definition of the resultant can be generalized to a system of forces F 1 , F 2 ,..., F n applied at points O 1, O 2,..., O n of the solid body. A point O, called the reduction point, is selected, and a system of parallel transferred forces equal in magnitude and direction to the forces is built at it F 1 , F 2 ,..., F n. Resultant R of these parallel transferred vectors, i.e. the vector represented by the closing side of the force polygon is called the resultant of the forces acting on the body (Fig. 2). It is clear that the vector R does not depend on the selected reference point. If the vector magnitude R(segment ON) is not equal to zero, then the body cannot be at rest: in accordance with Newton’s law, any body on which a force acts must move with acceleration. Thus, a body can be in a state of equilibrium only if the resultant of all forces applied to it is equal to zero. However, this necessary condition cannot be considered sufficient - a body can move when the resultant of all forces applied to it is equal to zero.

As a simple but important example to explain this, consider a thin rigid rod of length l, the weight of which is negligible compared to the magnitude of the forces applied to it. Let two forces act on the rod F And -F, applied to its ends, equal in magnitude, but oppositely directed, as shown in Fig. 3, A. In this case, the resultant R equal to F – F= 0, but the rod will not be in equilibrium; obviously it will rotate around its midpoint O. A system of two equal but oppositely directed forces acting in more than one straight line is a “force couple”, which can be characterized by the product of the magnitude of the force F on the "shoulder" l. The significance of such a product can be shown by the following reasoning, which illustrates the rule of leverage derived by Archimedes and leads to the conclusion about the condition of rotational equilibrium. Let us consider a light homogeneous rigid rod capable of rotating around an axis at point O, which is acted upon by a force F 1 applied at a distance l 1 from the axis, as shown in Fig. 3, b. Under force F 1 rod will rotate around point O. As you can easily see from experience, rotation of such a rod can be prevented by applying some force F 2 at this distance l 2 so that the equality holds F 2 l 2 = F 1 l 1 .

Thus, rotation can be prevented in countless ways. It is only important to choose the force and the point of its application so that the product of the force by the shoulder is equal to F 1 l 1. This is the rule of leverage.

It is not difficult to derive the equilibrium conditions for the system. Action of forces F 1 and F 2 on the axis causes counteraction in the form of a reaction force R, applied at point O and directed opposite to the forces F 1 and F 2. According to the law of mechanics about action and reaction, the magnitude of the reaction R equal to the sum of forces F 1 + F 2. Therefore, the resultant of all forces acting on the system is equal to F 1 + F 2 + R= 0, so the necessary equilibrium condition noted above is satisfied. Strength F 1 creates a torque acting clockwise, i.e. moment of force F 1 l 1 relative to point O, which is balanced by a counterclockwise torque F 2 l 2 powers F 2. Obviously, the condition for equilibrium of a body is the equality of the algebraic sum of moments to zero, excluding the possibility of rotation. If strength F acts on the rod at an angle q, as shown in Fig. 4, A, then this force can be represented as the sum of two components, one of which ( F p), value F cos q, acts parallel to the rod and is balanced by the reaction of the support - F p , and the other ( F n), size F sin q, directed at right angles to the lever. In this case, the torque is equal to Fl sin q; it can be balanced by any force that creates an equal torque acting counterclockwise.

To make it easier to take into account the signs of moments in cases where a lot of forces act on the body, the moment of force F relative to any point O of the body (Fig. 4, b) can be considered as a vector L, equal to the vector product r ґ F position vector r to strength F. Thus, L = rґ F. It is easy to show that if a rigid body is acted upon by a system of forces applied at points O 1 , O 2 ,..., O n (Fig. 5), then this system can be replaced by the resultant R strength F 1 , F 2 ,..., F n applied at any point Oў of the body, and a pair of forces L, the moment of which is equal to the sum [ r 1 ґ F 1 ] + [r 2 ґ F 2 ] +... + [r nґ F n]. To verify this, it is enough to mentally apply at point Oў a system of pairs of equal but oppositely directed forces F 1 and - F 1 ; F 2 and - F 2 ;...; F n and - F n, which obviously will not change the state of the solid.

But strength F 1 applied at point O 1, and force – F 1 applied at point Oў form a pair of forces, the moment of which relative to point Oў is equal to r 1 ґ F 1. Likewise the strength F 2 and - F 2 applied at points O 2 and Oў, respectively, form a pair with a moment r 2 ґ F 2, etc. Total moment L of all such pairs relative to the point Oў is given by the vector equality L = [r 1 ґ F 1 ] + [r 2 ґ F 2 ] +... + [r nґ F n]. Other forces F 1 , F 2 ,..., F n applied at point Oў, in total they give the resultant R. But the system cannot be in equilibrium if the quantities R And L are different from zero. Consequently, the condition for the values ​​to be equal to zero at the same time R And L is a necessary condition for equilibrium. It can be shown that it is also sufficient if the body is initially at rest. So, the equilibrium problem is reduced to two analytical conditions: R= 0 and L= 0. These two equations represent a mathematical representation of the principle of equilibrium.

Theoretical principles of statics are widely used in the analysis of forces acting on structures and structures. In the case of a continuous distribution of forces, the sums that give the resulting moment L and resultant R, are replaced by integrals and in accordance with the usual methods of integral calculus.

Strength is a vector. Force units

Material point. Absolutely solid and deformable bodies

Let us dwell on the basic concepts of statics, which entered science as a result of centuries-old practical activities person.

One of these basic concepts is the concept material point. The body can be considered as a material point, that is, it can be represented as a geometric point in which the entire mass of the body is concentrated, in the case when the dimensions of the body do not matter in the problem under consideration. For example, when studying the motion of planets and satellites, they are considered material points, since the sizes of planets and satellites are negligible compared to the sizes of orbits. On the other hand, when studying the movement of a planet (for example, the Earth) around its axis, it can no longer be considered a material point. A body can be considered a material point in all cases when, during movement, all its points have the same trajectories.

A system is a collection of material points whose movements and positions are interdependent. It follows from this that any physical body can be considered as a system of material points.

When studying equilibrium, bodies are considered absolutely solid, non-deformable (or absolutely rigid), i.e. they assume that no external influences do not cause changes in their size and shape and that the distance between any two points of the body always remains the same. In reality, all bodies, under the influence of force from other bodies, change their size and shape. So, if a rod, for example, made of steel or wood, is compressed, its length will decrease, and when stretched, it will correspondingly increase (Fig. 1, A). The shape of a rod lying on two supports also changes under the action of a load perpendicular to its axis (Fig. 1, b). At the same time, the rod bends.

In the overwhelming majority of cases, the deformations of the bodies (parts) that make up machines, apparatuses and structures are very small, and when studying the movement and equilibrium of these objects, the deformations can be neglected. Thus, the concept of an absolutely rigid body is conditional (abstraction). This concept is introduced to simplify the study of the laws of equilibrium and motion of bodies. Only after studying the mechanics of an absolutely rigid body can one begin to study the equilibrium and motion of deformable bodies, liquids, etc. When calculating strength, considered after studying the statics of an absolutely rigid body, it is necessary to take into account the deformations of bodies. In these calculations, deformations play a significant role and cannot be neglected.

Strength is a vector. Force units

In mechanics the concept is introduced strength, which is extremely widely used in other sciences. The physical essence of this concept is clear to every person directly from experience.

Fig. 1. Deformation of bodies under the influence of force:

A- compression-tension deformation;

b- bending deformation.

Let us dwell on the definition of force for absolutely rigid bodies. These bodies can interact, as a result of which the nature of their movement changes. Force is a measure of the interaction of bodies. For example, the interaction of planets and the Sun is determined by gravitational forces, the interaction of the Earth and different bodies on its surface - by gravity, etc.

It should be emphasized that during the interaction of real, and not absolutely rigid bodies, the resulting forces can not only lead to a change in the nature of their movement, but also cause a change in the shape or size of these bodies. In other words, in real physical bodies forces cause deformations.

Mechanics considers and studies not the nature of the acting forces, but the effect they produce. The effect of a force is determined by three factors that completely determine it:

2. Numerical value(module);

3. Application point.

In other words, power is vector quantity.

In addition to forces, in mechanics there are often other vector quantities- in particular, speed, acceleration.

A quantity that has no direction is called scalar or scalar quantity, TO scalar quantities include, for example, time, temperature, volume, etc.

A vector is represented by a segment with an arrow at the end. The direction of the arrow indicates the direction of the vector, the length of the segment indicates the magnitude of the vector plotted on the selected scale.

We don’t know how things were with physics at school and how much you liked this subject, but after today’s post, your attitude towards it will definitely change. Because if you look inside all the exercises, you will find a curious thing - they are all built on the principles of Newtonian mechanics! And it is the mechanics that determine how effective this or that exercise will be for specific group muscles.

the power itself on her shoulder. Under the shoulder in in this case is understood shortest distance from the line along which the force passes to the axis of rotation.

Let's look at this using the example of push-ups with standard hand placement:

It can be seen that the force of gravity that affects the athlete passes through three joints - the shoulder, elbow and wrist. In this case, the load decreases as the force passes through each subsequent joint. That is, the main load goes to the shoulder joint (and, accordingly, the pectoral muscles), and the triceps receive less load, since the load on flexion at the elbow joint is minimal.

Is it possible to change the technique of push-ups in such a way as to increase the load on the triceps? Of course, since now we know what needs to be created torque, aimed at flexion at the elbow joint. Then the triceps will start working, counteracting such an effort. To achieve this effect, it is necessary to make sure that the force of gravity has a shoulder relative to the elbow joint. This can be achieved, for example, by moving your hands closer to each other.

It would seem that we only slightly changed the position of the hands, but at the same time we were able to significantly increase the load on the triceps and make the exercise more targeted! And such moments huge amount! Therefore, if you want your training to be effective, you need to always think about what, how and why you are doing, trying to get the most out of every rep in every set!

http://site/uploads/userfiles/5540.jpg We don’t know how things were with physics at school and how much you liked this subject, but after today’s post, your attitude towards it will definitely change. Because if you look inside all the exercises, you will find a curious thing - they are all built on the principles of Newtonian mechanics! And it is the mechanics that determine how effective a particular exercise will be for a specific muscle group. Let's start by looking at a schematic image of a person. The main joints are indicated in red, because all movements occur in them. As you know, muscles are attached to bones (with the help of tendons), and our body is so wonderfully designed that for each joint there are two muscle groups (antagonists) that allow rotation in opposite directions..jpg The rotational load that sets everything in motion is called the moment of force and is equal to the product the power itself on her shoulder. In this case, the shoulder is understood as the shortest distance from the line along which the force passes to the axis of rotation..jpg It can be seen that the force of gravity that affects the athlete passes through three joints - the shoulder, elbow and wrist. In this case, the load decreases as the force passes through each subsequent joint. That is, the main load goes to the shoulder joint (and, accordingly, the pectoral muscles), and the triceps receive less load, since the load on flexion at the elbow joint is minimal. Is it possible to change the technique of push-ups in such a way as to increase the load on the triceps? Of course, since now we know that we need to create a torque aimed at bending the elbow joint. Then the triceps will start working, counteracting such an effort. To achieve this effect, it is necessary to make sure that the force of gravity has a shoulder relative to the elbow joint. This can be achieved, for example, by moving your hands closer to each other..jpg It would seem that we only slightly changed the position of the hands, but at the same time we were able to significantly increase the load on the triceps and make the exercise more targeted! And there are a huge number of such moments! Therefore, if you want your training to be effective, you need to always think about what, how and why you are doing, trying to get the most out of every rep in every set! 100-day workout - Contents