You have a sedentary lifestyle. Then it is absolutely necessary to strengthen the muscles of the back. This complex must be performed at least 2-3 times a week.
6 simple exercises
Sitting on the floor with outstretched legs, grab your ankles with your hands. Straighten, then repeat the exercise several times.
Sitting on the floor, bend one leg at the knee and stretch the other. Grab your toe on the corresponding leg. Repeat the exercise several times, changing the position of the arms and legs.
Sitting cross-legged, bend your elbows above your head, touching your fingers with your shoulders. With one hand, push the elbow of the other hand back behind the back. Change the position of the hands and repeat this several times.
Sitting on the floor with legs crossed, arms crossed behind the back of the head, turn the body first one way and then the other way several times.
From the position of the first exercise, bend one leg at the knee with the foot on the floor. With one hand, grab the knee of the other leg, turning the body and holding the other hand behind the back. Stay in this position for a few seconds. Repeat the exercise several times, changing the position of the arms and legs.
Sitting with legs crossed and arms behind your back, bend the body forward, raising your arms up. Then straighten up. Repeat the exercise several times.