The therapist applies a rhythmical, repetitive movement called oscillation. This is usually done in a posterior-anterior direction. In other words, the therapist places his or her hands on your spine and presses downward toward the front of the body. In one-minute, the therapist can move the joint about 30 times.
This type of gentle mobilization can stretch contracted tissue in and around the joint without harming the other soft tissues nearby. Doing the motion over and over helps milk the joint. This means the synovial fluid protecting the joint is evenly redistributed throughout the joint. The result is decreased resistance to motion. This makes for smoother motion and less pain.