Biomechanics in the gym to pump up muscles, using the lever principle

If you are involved with a barbell or dumbbells, you probably have heard the basic rules and tips: "When you do the deadlift, we must keep bar close to the feet, "" If you take the squat pelvis back, buttocks big load "or" barbell bench press close grip shifts the emphasis on triceps ".

And these rules actually work. But why is this happening and how to shift the burden to the less-known exercises? Understand this, a simple mechanism - a lever.

As the principle of the lever is realized in our body

Lever - this body, which can rotate around a fixed support. It helps to lift more weight with less effort. He has a point of support and the axis of rotation. There is a force that is applied to its end, and forces the shoulder - the shortest distance from the axis of rotation to the point of application of force.

Torque = force × arm strength

And the longer the arm, the more torque.

All our joints are working on the principle of the lever. Muscles via tendons are attached to the bones, cut and pulled them, making movement. For example, two heads

biceps, Biceps shoulder, attached to the radius. When you bend your arm, the biceps is reduced (force) and creates a torque in the elbow joint (axis of rotation). The thicker your biceps, the more increases the torque. And this is understandable: pumped athlete will raise more than a thin girl.

At the same time has the value and strength of the shoulder - the distance from the pivot point to the point of force application. Therefore, the greater the distance from the joint to the point of attachment of the tendon, the stronger man. However, this physiological features of the structure, which can not be changed. And the differences between people in this area are not that great.

Another thing - the shoulder to the point of application of the reaction force, such as weights, a barbell or weight of his body. Let's take the same example with bending arms at the elbow, just add a dumbbell for clarity.

When you bend your arm, the axis of rotation is at the elbow (green dot). fulcrum - a dumbbellThat pulls the arm down by gravity (red dot). A force arm - from the elbow to the perpendicular axis, which forms the dumbbell (green line).

When you lower the arm, shoulder strength decreases, and with it, and the load on the biceps. Shoulder strength as much as possible when the forearm parallel to the floor, which means that at this point the most powerful and the load on the muscles.

How to apply the principle of the lever in the gym

Assessing the moment arm from the bar or dumbbells to the joint, you will always know how to bend the limbs or body to provide maximum load on the dates of your muscles and prevent overload, if it is undesirable.

Find out what the point of the exercise load on the muscles maximum

The longer the lever arm, the greater the load gets muscle. For example, in lifting dumbbells for biceps shoulder strength increases as you raise your hand, and reaches its maximum length when the arm is bent at the elbow at an angle of 90 °. Further, the load begins to decrease again until at the top does not reach the minimum.

Take more exercise: bench press bar lying narrow grip. Here, the load on the triceps will be maximum at the bottom and the lowest at the top.

But in the bench press a conventional grip, on the contrary, shoulder strength and the load decreases at a low point when the wrist is above the elbow, and the top is enhanced.

The deadlift maximum load is also at the lowest point, because the moment arm from the hips to the top of the bar is the longest. By the way, so you need to keep the bar close to your feet and keep it up, almost touching the lower legs: so you shoulder cut power to the hip joint and reduces the load that can be critical when lifting much weight.

Take hyperextension. Shoulder strength to the hip as much as possible when the body is parallel to the floor. In an attempt to increase the load on his back and buttocks in the hands of people take a pancake, or put him on his back. However, a much more efficient to keep it pressed against the head: in this case the lever arm of the weighting to the hip joint will be more, which means you get the same effect with less weight.

To determine at what point the muscles tense up more, you will adjust the load. For example, it is possible to slow down the movement of the point of maximum load and speed where the shoulder strength and low load.

In addition, you will not reduce the range of motion where it can affect the effectiveness of the exercise. For example, do flexing the biceps of parallel above or throw the bar after becoming instead take place smoothly and lifting and lowering.

Shift the emphasis on the proper muscles in various exercises

Let us examine an example squats. There are several types of exercises: barbell on the back, chest, Smith simulator. Consider all of these provisions in terms of leverage.

When you squat with a barbell on his back, shoulder strength to the hip more than shoulder strength to the knee. That is, the quadriceps, knee flexor, then performs less work than in the variant with a barbell on his chest. It confirmsKinematic and EMG activities during front and back squat variations in maximum loads research using electromyography.

Moreover, in the squat with a barbell on the back of increasing shoulder strength from sports equipment to waist, so that the lumbar spine experiences a greater load than in the squat with barbell on his chest. And the more you lean forward, the higher the load and the greater the risk of injury.

And now look at the squat Smith simulator.

Shoulder strength to the knee is simply huge, but a basin it is almost there. There does not swing glutes, quads only. At the same time, of course, increases the load on the knees. So, this exercise is great for pumping the quadriceps, but here for the buttocks, it is useless.

Many girls in the gym like doing lunges with dumbbells for pumping thighs and buttocks. I must say that this is not the best way to swing the priest: is an exercise much more effective. But they can increase the load on the buttocks.

Look on the shoulders of forces. If you do a lunge with direct body, shoulder strength from the point of application of force to the knee as much as possible, and to the buttocks is minimal. Consequently, the entire load out on the quads. Indeed, the studyHAMSTRINGS, QUADRICEPS, AND GLUTEAL MUSCLE ACTIVATION DURING RESISTANCE TRAINING EXERCISES shows that attacks well pumped all the heads of the quadriceps.

If you want more to load the buttocks, it is necessary to increase the lever arm from the bar or dumbbell to the hip - just tilt your body forward.

We now take any upper body exercise. For example, bench standing. Often during his performance encircle the head, afraid to touch her chin. I touched jogging shvunge and it is very unpleasant. Therefore, some exercise equipment so encircle the head, but it increases the load and allows you to take more weight.

Let's look at the trajectory of the bar: if it goes in a straight line, shoulder strength is minimal, if encircles the head, it increases and keep it much more difficult.

Thus, you can adjust the load, taking the distance from the joint to the point of force application, and shift it to the desired muscle groups.