Mobilization
From neuro-centered training to increase mobility in the lower back and lumbar spine: Open your mouth slightly and move your lower jaw 5-6 times to the left and right; repeat several times a day.
“Pillow squeeze”: Lie on your back with your knees bent at about 90 degrees and your feet in the air; place a large pillow between your knees and squeeze it briefly: this realigns the pelvic bones.
Strengthening:
Lie on your back with your feet at the floor; press your lower back down onto the mat, alternately extending one leg straight out in front of you; make sure that your lower back remains on the floor; 15-20 repetitions on each side
For psoas or sciatic pain: Strengthen the psoas: lie on your side, bend your knees, place your upper hand on your hip to prevent your pelvis from tilting; open your upper knee as far as possible, without tilting your hip, the feet stay on each other; 20-30 repetitions, then switch sides; possibly 2-3 sets (depending on how much is possible); for several days
Wall sitting: sit on an imaginary chair against the wall/door, back at the wall/door, legs at an angle of approximately 90° or slightly more if you are not very fit.
Your feet should be flat on the floor; make sure that your weight is distributed as evenly as possible; if possible, press your lower back against the wall/door or roll towards the wall and away again; breathe calmly and hold the position for as long as possible (60-90 seconds is the goal); repeat 2-3 times if necessary.