The starting position is the same. Raise your straight legs one at a time, 4-8 times each. The starting position is the same. Alternately pull your bent legs towards your stomach. Perform this movement 6-8 times with each leg.

The kidneys are not a static organ; they have a certain physiological mobility. For example, when breathing or physical activity, the kidneys move. The norm is considered to be a displacement of one lumbar vertebra. If the vertical deviations exceed two centimeters, then we are talking about pathological displacement or nephroptosis.

Since the kidneys in their anatomical bed are fixed by ligaments, surrounding fascia and perinephric fatty tissue, when under the influence of negative factors or with age their atrophy occurs, it is quite natural that the kidneys descend below two centimeters. Certain physical exercises can help restore the correct position of the organ.

When the kidneys prolapse, both surgical and conservative treatment is carried out, which is based on special physical exercises that can ensure the return of the organ to its anatomical place. However, they can only be performed, especially at the initial stage of treatment, under the supervision of a doctor. Classes begin only after a thorough diagnosis and diagnosis. For each person with this problem, an individual set of exercises is selected. Indications for physical therapy are the 1st and 2nd degree of development of nephroptosis; in the third degree, the exercises will not be effective, so only surgical intervention can help the patient.

Despite the proven positive dynamics after physical exercise, there are a number of contraindications when exercise therapy is strictly prohibited, among them:

• complications in the form of structural changes in the kidneys;
• disturbance of urine outflow;
• high blood pressure;
• high body temperature;
• menstruation;
• threat of internal bleeding;
• large kidney and gallstones;
• acute infectious diseases;
• oncology.

Nephroptosis is a rather complex disease, so the following types of exercises should be avoided:

• at any stage of the disease, strength training on exercise machines and lifting weights should not be performed;
• with body shaking, such as running, jumping, squats;
• exercise bike, treadmill, orbit track;
• from football, volleyball, basketball;
• in the form of sharp slopes.

In addition, when compiling a complex of exercise therapy, the presence of other health problems is also taken into account. For example, with arterial hypertension and varicose veins in the legs, static elements in the treatment complex should be abandoned.

We also note that people who first encountered the problem of kidney prolapse mistakenly assume that now they will need to completely change their lifestyle and give up sports, and women will stop keeping their figure in shape. No, physical activity for nephroptosis, on the contrary, is recommended. However, the approach to sports and physical activity will have to be changed, since, as noted above, shaking the kidneys is contraindicated, so it would be more correct to visit a qualified specialist and jointly select the type of sports activity.

In addition, it is worth taking into account the stage of the disease, at the first stage physical activity is useful, since controlled loads can return the organ to its place, at the second stage the approach to exercises and sports should be extremely careful, the loads are minimal, and at the third stage even the slightest load threatens disastrous consequences.

Therapeutic exercises for nephroptosis are a guarantee of health. A specially designed set of exercises must be performed daily. As a rule, it includes exercises that strengthen muscle tissue in the abdominal cavity and lower back; exercise helps to increase intra-abdominal pressure. Thanks to the indicated effects, the prolapsed kidney returns to its anatomical location. Also, therapeutic exercises have a beneficial effect on the functions of the genitourinary system, and overall well-being.

Therapeutic physical exercises for nephroptosis should be based on the following principles:

1. An integrated and systematic approach. Charging should be regular. The exercises are performed once or twice for thirty to fifty minutes.
2. Subsequence. There must be a warm-up, a main complex and final exercises.
3. Increasing load. Depending on the stage of the disease, the amount of exercise is gradually increased. The initial complex consists of 10-12 exercises, which are repeated 4 times, then additional exercises are introduced.

Exercise therapy consists of special and general developmental exercises.

Special ones are aimed at strengthening the muscles and tendons in the kidney area, these are:

• dynamic breathing exercises to strengthen skeletal muscles and normalize metabolic processes;
• static – tension of certain muscles in a fixed position, that is, targeted tension and relaxation occurs;
• diaphragmatic and chest breathing in static conditions.

Diaphragmatic or abdominal breathing uses the powerful muscle between the chest and abdominal cavity. It ensures blood saturation with oxygen and prevents the development of respiratory diseases.

Chest breathing can be clavicular or costal. During exercises, it is necessary to develop the costal muscle, which involves all the intercostal muscles. You need to do it as follows:

• simultaneous inhalation through the mouth and nose, while we draw in the stomach, and raise and round the ribs;
• exhale through the nose, gradually the abdominal muscles relax and the chest drops;
• pause for three to five seconds.

General strengthening exercises include simple movements of different parts of the body, exercises for correcting posture and coordination.

The basis of exercise therapy for nephroptosis is a horizontal position of the body or at an angle of no more than 60 degrees relative to the plane.

From sports equipment you can use rollers, a small ball, a fitball, an inclined Evminov board, an expander tape.

Immediately before charging, it is important to ventilate the room well, wear loose clothing and comfortable shoes. The exercises should be performed on a special gymnastic mat.

Exercises are done on an empty stomach or two to three hours after eating.

Video on the topic

There are quite a lot of elements of gymnastic exercises that strengthen muscles and return the wandering kidney. Let's focus our attention on the Bubnovsky gymnastics complex. The doctor has developed a whole series of unique techniques that are capable of restoring the human body after serious injuries and displacement of internal organs. Bubnovsky’s gymnastics for nephroptosis quickly and effectively allows you to return the kidney to its place.

This technique does not require visiting a specialized clinic or simulators. The main task of the proposed exercises is to activate the activity of the deep muscles of the trunk. All of them are performed while lying on your back:

• legs straight, pressed tightly against each other, slowly rise perpendicular to the floor while inhaling, and lower as you exhale. The exercise is repeated 10 times;
• “bicycle”, rhythmic breathing, perform for two minutes;
• bend your knees and alternately press your thighs to your chest, repeat 10-12 times;
• strongly squeeze a small ball in your knees and hold it in this position for ten seconds, after relaxing, repeats – 8;
• legs together straight, bend left and right.

As the muscles become stronger and endurance is trained, the number of repetitions can be increased and the following exercises can be additionally performed:

• lying on your back, straight legs should be thrown back behind your head, and your hands should reach your toes; it is also important to monitor your breathing, it should be rhythmic;
• “Birch”, you need to try to hold your body in this position for as long as possible;
• “Bridge”, you should bend in such a way that your stomach rises as high as possible and your body forms an arc.

Bubnovsky exercises should be performed daily for about three to four months. If further examination does not reveal a worsening of the condition, then at the first stage of nephroptosis, you can add bending of the back up and down from the knee-elbow position. The exercise should be done smoothly, without tension.

Yoga is a fairly ancient technique, the basis of which is the restoration of mental and physiological balance. Yoga therapy is actively used in the first and second stages of nephroptosis, asanas are selected on an individual basis. They support the functioning of the cardiovascular and respiratory systems.

At the third stage of the disease, the possibility of practicing yoga should be discussed with your doctor. As a rule, classes can be resumed after surgical treatment.

All asanas are performed at a slow pace, without sudden movements and serious effort. Therefore, this method of treatment is perfect for weakened and elderly people.

A set of exercises helps restore the balance of the body’s internal forces, improve overall well-being and cure various ailments.

The most effective asanas for kidney prolapse:

• “extended triangle”, initial standing position, legs stand parallel to one another, then the left foot needs to be turned inward, and the right foot outward, arms spread to the sides with palms down. Now you can perform bends in such a way that the right hand falls to the right leg, and the left one rises up at this moment. As you exhale, the chest, stomach and head turn towards the raised hand. You need to stand in this position for three minutes. Breathing is even. Then do the same exercise on the left side.
• “staff”, you need to sit on the floor, legs extended and joined at the feet. While inhaling deeply, bend your torso forward as deeply as possible, it’s good if you can reach your feet with your hands. Then, while taking a deep breath, you need to return to the starting position.
• in case of deficiency of perirenal fatty tissue, yogic practices are recommended, the basis of which are breathing techniques and relaxation.

There are other yoga asanas that are helpful for kidney prolapse. Only a specialist can determine which ones are indicated in a particular case.

You should also take into account the fact that nephroptosis has many contraindications, therefore, like physical activity, yoga asanas can aggravate the condition if performed without a doctor’s recommendations.

According to medical statistics, women are much more likely to suffer from kidney prolapse than men. But they have one problem - weakening of the ligaments and muscles that hold the organ in its anatomical position. Therefore, all courses of gymnastic exercises, both for women and men, have a single goal - to strengthen the abs, back and sides, thereby ensuring the return of the kidney to its place.

So, let's look at the basic exercises that are recommended to be performed during warm-up.

Starting position – lying on your back. Legs straightened, arms along the body. As you inhale, the legs rise up, and as you exhale, they lower.

The next exercise is to put your hands behind your head and lock them together, raise your legs a little and without lifting your back from the floor, you should turn in one direction and the other so that each leg is alternately at the top.

Then we lift our legs off the floor five centimeters and hold them in this position for ten seconds. The warm-up complex also includes breathing exercises: while inhaling, we draw in the stomach, while exhaling, we stick it out.

After completing these simple exercises for five to ten approaches, you can begin the main exercise.

All exercises are performed while lying on your back. It includes the “bicycle” already known to us from Bubnovsky’s method, and we supplement it with the “scissors” exercise. It is performed simply: the legs are raised ten centimeters from the floor, first spread wide, and then criss-crossed. You need to do it ten to twelve times.

In a lying position, you need to imitate walking, alternately bending and straightening your legs.

Pulling your legs towards your chest as you inhale and lowering them as you exhale.

Another effective exercise is to raise your legs at a ninety-degree angle, spread them out to the side as wide as possible, then, as you exhale, bring them together and lower them to the floor.

These are simple exercises that do not require much physical effort. If the doctor sees that the patient can cope with them quite well and there are no contraindications, then new exercises, somewhat more complicated, are added to the complex.

We are talking about exercises that are performed on the side and in the knee-elbow position.

Charging is performed alternately, first on one side, then on the other.

And so, you need to stretch out your hand and lower your head on it, and raise your upper leg as high as possible. Stay in this position for five to seven seconds and, as you exhale, lower your leg. Do the same on the other side.

The next exercise is to lie on your side, pull your leg towards your stomach, and while exhaling, return it back. Do twelve times. Do the same on the other side.

The same exercise can be performed from the knee-elbow position.

An exercise called “cat” also has a very beneficial effect on the back and abdominal muscles. Its essence is that, while in a knee-elbow position, while inhaling, arch your back upward, hold it a little and lower it down as you exhale. Must be performed at least fifteen times.

Even more complex exercises include:

• “birch tree, it is written about in Bubnovsky’s method;
• “plow”, we are talking about an exercise in which, from a supine position, the legs are thrown over the head and the toes touch the floor. It is important to stay in this position for two to three minutes.

• lying on your back, head thrown back quite strongly, you need to try to touch the floor with your forehead.
• “abdominal lock”, you should sit down and bend your legs so that your knees are as close to the floor as possible. Place your palms on them, exhale deeply and draw in your stomach. It is important to sit for as long as possible, after which you need to slowly relax your stomach and inhale. The exercise trains breathing well, which is very important when the kidneys prolapse.

It is also important to understand that physical therapy is only an additional method of treating kidney prolapse, although it is quite effective. Therefore, drug therapy and surgical intervention cannot be ruled out.

It should be understood that without proper treatment, nephroptosis can lead to more than serious consequences, namely:

• to infectious and inflammatory diseases;
• to acute or chronic kidney failure;
• to miscarriage or the birth of children with congenital pathologies of the respiratory and cardiovascular systems;
• shrinkage of the organ, its complete dysfunction and death.

Therefore, it is very important to promptly and correctly treat this pathology.

However, it is worth remembering that the article provides only general descriptions of certain complexes and exercises. Under no circumstances should you perform physical therapy or yoga without a doctor’s permission if your kidneys are prolapsed, as you can cause serious harm to your body.

With nephroptosis, the structures that support the kidney normally are weakened or atrophied: fascia, diaphragm, abdominal muscles, lumbar muscles, and the own fat capsule. Physical therapy for this pathology is one of the most important components included in the complex treatment of the disease. Properly selected exercises will help return the organ to its physiological position without surgical intervention.

• Show all

  Main causes of nephroptosis

  The reasons that cause nephroptosis in men can be completely different:

  Nephroptosis can also be congenital. If the kidney is not lowered by more than 2/3 of its size and its function is not impaired, then no serious manipulations should be performed.

  Regular physical therapy will help prevent various complications.

  

  Indications and contraindications for prescribing exercise therapy for kidney prolapse

  Prolapse of the right kidney occurs more often than the left. Nephroptosis of the 1st degree can be cured by gymnastics.

  The prolapse of the kidneys of the second stage is characterized by the fact that they protrude along their entire length from the hypochondrium into the abdominal cavity, therefore wearing a renal band and physical therapy are used.

  When grade 3 is reached, surgical intervention is required, as the organ is completely displaced into the abdominal cavity.

  You cannot do exercise therapy if:

  • cardiovascular pathology;
  • acute or exacerbation of chronic inflammatory diseases;
  • injuries to the skull or spine;
  • diseases of the hematopoietic organs or blood system;
  • neoplasms of a malignant or unknown nature.

  Stones in the organ are an absolute indication for surgical treatment for nephroptosis. In this case, exercise therapy is not recommended, as this may cause an exacerbation.

  

  General rules for performing physical therapy complexes

  Therapeutic exercises for kidney prolapse can effectively strengthen the structures that support the organ. To achieve maximum results, it should be performed in the morning and every day, only in this way will it provide the necessary benefits.

  Exercise therapy should be carried out on a mat or thick blanket spread on the floor, or a bed with a high degree of rigidity. For classes, you need to choose comfortable clothes that will not restrict movement.

  Before starting physical exercise, you need to do a regular warm-up to warm up your muscles.

  The duration of the workout can be from 20 to 30 minutes. Over time, it is recommended to gradually increase the load, supplementing the complexes with new types of exercises.

  It is necessary to choose a slow pace of movements, without sharp turns or twisting of the body. You cannot exercise on a full or empty stomach. After eating, at least 30 minutes should pass.

  

  Exercises while lying down

  The easiest way to start physical therapy is with exercises while lying on your back.

  The following complex will help strengthen the muscle frame:

  Job title	Performance
  Task "Bicycle"	1. Starting position – lying on your back. 2. Raise your legs up to an inclination angle of 15-30 degrees and “twist” the pedals of an imaginary bicycle, straightening and bending your knees
  Mission "Scissors"	1. Raise your outstretched legs at a distance of 20 cm from the floor. 2. Spread them wide apart and bring them together again, crossing them so that each time either the left or the right leg is on top
  Raising the torso	1. Place emphasis on your legs bent at the knees and on your shoulders, lifting and lowering your pelvis. 2. At the top point when lifting, it is recommended to hold for 2-3 seconds
  Squeezing the ball with your knees	1. Take a medium-sized ball, place it between your legs bent at the knees and squeeze with force for about 5 seconds. 2. Subsequently, you can increase the compression time
  Alternating straight leg raises	In a lying position, lift first one leg and then the other

  Exercise therapy on all fours and stomach

  Exercises for nephroptosis in men also include training the back muscles. It is recommended to do this using the following complexes:

  Job title	Performance
  Quest "Swimmer"	1. Starting position – lying on your stomach. 2. Raise the opposite arm and leg at the same time. 3. It is recommended to perform at least 6 repetitions for each side
  Planck task	1. Starting position – lying on your stomach, then get into a push-up position. 2. It is recommended to hold the plank for as long as possible. 3. After 15-20 seconds of performing a statistical task, the muscles of the arms, legs, back and abdomen will be tense
  Maintaining balanceon all fours	Lift the opposite leg and arm in turn, and focus on the other leg
  Quest "Cat"	1. Take a knee-elbow position (arms bent at the elbows, legs at the knees). 2. Next, arch your back up and back. 3. Repeat the task about 15 times

  Additional exercises

  Very often, gymnastics is supplemented with tasks such as:

  • Breathing exercise: when inhaling, the patient inflates his stomach and holds his breath for a few seconds. After this, he exhales (sucking in the abdomen) and holds his breath.
  • Exercise with a roller under the back: while exhaling, a person bends his right leg at the knee, and while inhaling, returns it to its original position. You need to repeat 10 times.

  Exercise therapy for kidney prolapse in men includes a large number of complexes. Well-known doctors Bubnovsky and Chikharev have developed techniques that make it possible to restore the fixation apparatus.

  Bubnovsky's gymnastics

  The Bubnovsky method was created to restore the spine and consists of performing treatment with movements (kinesitherapy). Some exercises:

  Exercise name	Performance
  Relaxation and contraction of back muscles	Lying on your side, cross your arms behind your neck. Bend your legs at the knees. After this, make a movement aimed at bringing the elbows and knees together.

Kidney prolapse or nephroptosis is becoming more and more common every year, especially in older people, although young people are not immune from this disease. Oddly enough, the reasons for its development are sudden weight loss, a sedentary lifestyle and, conversely, work associated with heavy lifting; even pregnancy and childbirth can provoke prolapse of the kidney.

But it is possible to cope with the problem. Today this is done through surgery, and in mild cases it is enough to regularly engage in exercise therapy for nephroptosis.

Ways to combat nephroptosis

In the arsenal of modern doctors there are only 2 effective methods that allow this: surgery and exercise therapy. The first is based on strengthening the ligamentous apparatus of the organ artificially, while in the second case, the ligaments and muscles are strengthened through regular training, which gives long-term results.

Attention! An operation, even performed by the best doctor, does not protect the patient from relapse, that is, repeated prolapse of the kidney.

Thus, physical therapy for nephroptosis is the most preferred method of treatment. Moreover, it is indicated for patients who have undergone surgery in order to consolidate the achieved result.

How to do exercise therapy?

Since today there are many options for exercises indicated for nephroptosis, the complex is developed individually for each patient, based on the condition and location of the kidneys, the person’s physical fitness and the presence of concomitant diseases. But you need to treat exercise therapy responsibly and try not to miss workouts, since the regularity of classes and the correct execution of each exercise determines how much the abdominal, hip and back muscles will be strengthened, and, therefore, the success of therapy.

Physical therapy should be done in the morning on an empty stomach in a well-ventilated, but draft-free room where the proper level of illumination is provided. As for the floor, it must be level and fairly hard.

Advice: in good weather, it is best to do exercise therapy outdoors, for example, on the nearest playground or in the park.

For classes you will need:

• comfortable sports shoes;
• clothing that does not restrict movement;
• rug.

All patients should understand that the presence of nephroptosis of any degree is a contraindication to jumping, running or lifting weights. But long walks and swimming will be an excellent addition to exercise therapy.

Attention! Before starting exercise, patients should definitely consult their doctor, since some exercises may be contraindicated for people with concomitant diseases, for example, problems with the cardiovascular system.

Complex 1

The exercises for nephroptosis listed below are considered the safest and simplest, so it is usually recommended to start with them.

1. From a lying position, slowly raise and lower your legs 8–10 times.
2. Raise your pelvis 10 times as high as possible, while pressing your legs tightly together.
3. Lying on your back, clasp your hands above your head and raise them up. At the same time, the legs connected together are raised parallel to the floor and then slowly lowered. Repeat 10 times.
4. Scissors. Similar to the previous exercise, the legs are first raised 20–30 cm above the floor and, as you inhale, spread them apart, and as you exhale, bring them together without lowering them to the floor. You can also cross your legs so that your right or left leg is on top. Repeat 10 times.
5. Lying on your back, you should take turns pulling your legs bent at the knees towards your stomach. Repeat 5-8 times on each leg.
6. Bike. From a lying position, with your hands folded under your head, perform leg movements that imitate riding a bicycle until you feel tired.
7. Cat. Get on all fours, straightening your arms and back, looking forward. On the count of 1, the back is arched like a wheel and at the same time the head is lowered so that the gaze is directed to the navel. On the count of 2, they bend in the opposite direction, trying to look at the top of their own head. Repeat 10–15 times.

Important: all exercises should be performed slowly without jerking or sudden movements, without lifting your lower back from the floor.

After completing your workout, it is extremely important to properly relax your muscles. To do this, still lying on the floor, close your eyes, stretch your arms and legs in different directions and lie down for a few minutes, breathing easily and freely.

Complex 2

Those who have been successfully practicing exercise therapy for nephroptosis for some time can gradually complicate their program and begin to perform so-called inverted exercises.

1. Plow. From a lying position, twists are performed so that the connected straight legs touch the floor behind the head. Stay in this position for 2–3 minutes.
2. Shoulder stand. The technique for performing this exercise is initially similar to the previous one, but then you need to fix the body for 1 minute so that the heels are pointing vertically upward and the hands are supporting the back.
3. Fish. From a lying position on your back, throw your head back, as if trying to reach your forehead to the floor. Stay for 20–30 seconds. This exercise must be performed last, as it is necessary for proper relaxation of the neck muscles.

Important: during menstruation, women should interrupt classes or switch to lighter exercises of complex 1.

Complex 3

Already advanced athletes can supplement their training with more difficult exercises, which will certainly increase the effectiveness of the entire complex. But before complicating your program, you must get a doctor’s approval, otherwise you can only worsen your condition.

1. Peacock. From a squatting position, they lean forward and, resting their stomach on their folded elbows, try to reach their forehead to the floor. At the extreme point, the head is slightly raised and fixed in this position. While performing this exercise, you should maintain deep and calm breathing.
2. Uddiyana bandha. Having taken a stable position with your knees slightly bent and your arms resting on them, you should pull in your stomach and hold your breath. Maintain this position for as long as possible, and then relax the abdominal muscles and take a calm breath. This breathing exercise should be practiced for at least 15 minutes daily.

Attention! With grade 3 nephroptosis, it is unsafe to perform the above exercises. In such cases, it is very important to improve your condition with lighter workouts.

Physical therapy for nephroptosis is the main type of conservative treatment. Exercises for kidney prolapse, which are recommended by many doctors, allow you to return the vagus organ to its place.

Starting set of exercises

Exercise therapy for nephroptosis is prescribed for the first two stages of the disease (at the third stage, conservative treatment is pointless). Thanks to it, you can achieve raising the kidney into place, or prevent its further descent.

Warm-up exercises

To begin, lie on the floor (most of the exercises for kidney prolapse are performed lying down). Begin to lift your legs together upward. All movements should be smooth and slow - take your time and do not forget to breathe correctly: inhale for effort - exhale for relaxation. This exercise can be performed with varying degrees of kidney prolapse.

Another exercise in the starting complex is twisting in both directions. First, extend your arms up and clasp them together. Raise your legs so that they are parallel to the floor. Carefully wrap yourself in one direction or the other. Don't forget about relaxation periods between crunches.

Basic set of exercises

This complex mainly contains exercises performed with the legs.

With different degrees of kidney prolapse, you need to use different angles of elevation and body position. So, for example, to correct the third degree, you need to raise your legs by 30 degrees, for the second - by 15. The first degree, as the simplest, does not require special stress.

Exercise 1 - “Bicycle”
A very popular exercise in this exercise therapy is cycling. Raise your knees bent and pedal for about 2 minutes. (Perform while lying on your back)

Exercise 2
Lying on your back, bend your knees and begin to pull them towards your stomach one by one. You need to do 5-8 repetitions on each leg.

Exercise 3
Starting position - lying on your back, legs bent at the knees, but feet pressed to the floor. Hold a ball between your knees (you will need a rubber one, but quite dense) and begin squeezing it with your knees for about 8 seconds. Repeat this exercise 8 times.

Exercise 4
It can be performed with varying degrees of kidney prolapse. Lying on your back, as you inhale, begin to raise your straight legs up, and as you exhale, lower them. Alternatively, you can do it like this: raise your legs so that they are located at an angle of 90 degrees in relation to your body. As you inhale, spread your legs in different directions, and as you exhale, bring them back together. The ideal number of repetitions is 6.

Exercise 5
Another very popular exercise for kidney prolapse. Lying on your side, begin to lift your straight leg up, about 8 times, and then do it on the other side.

Knee-elbow pose

When the kidneys prolapse, it is often recommended to use the knee-elbow position. Get on your knees, then rest the palms of both hands on the floor (the second position, when you need to rest with your entire forearm). Start arching your back: up and back. This exercise should be repeated about 15 times. With its help, the load on the back is reduced, and the organs have the opportunity to return to their place. It is also useful to simply stand in this position. This exercise is called "Cat".

What to consider when performing such gymnastics

Exercises for nephroptosis are considered one of the safest types of physical education. However, you still need to carefully prepare for it. You should not do gymnastics immediately after eating - you can cause problems with the digestive system.

The benefits of gymnastics for kidney diseases are undeniable. However, the effect can be achieved only if you maintain regularity of actions. This means that you need to practice every day. On average, such a charge will take you about 25 minutes, so it’s possible to find time for it even in a busy schedule.

If during the exercises you experience strange sensations, for example, dizziness (when performing the same “Cat”) or darkening in your eyes, and also if you feel pain, you should stop. Be sure to see a doctor after this.