Here the participant stands with feet hip width apart near a wall. He or she places his or her back on the wall and slides down until the thighs are parallel to the floor and the feet are directly under the knees or slightly farther out from the wall. Some combination of non-skid footwear and floor surface is necessary. The participant maintains the posture either until trembling is induced, or involuntary collapse (which tends to be a slide to the floor because the back still provides some braking). Informally this is also known as the 'block buster.'
Rationale: This exercise has a dual purpose. Because it exhausts the adductor and iliopsoas muscles, it can be an excellent preparation for working further with the pelvis, or relieving tension there. Also because it can be held until involuntary collapse, it can be an 'ego-shrinker.'
Source: Alexander Lowen