The Rumble rollers are foam rollers used to relieve muscle pain and tightness, adhesions, trigger points, and muscle knots. Conventional foam rollers have smooth surfaces that further compress soft tissue. Rolling on top of them improves blood flow and tissue flexibility, but the effect is limited and relatively superficial, unless you spend a lot of time rolling. The Rumble Roller was created to perform this therapy more effectively. The surface of the Rumble Roller contains specially designed bumps that are firm, but flexible. The rumble rollers come in regular and extra firm support. The bumps continuously knead the contours of your body, gently stretching soft tissue in multiple directions ( side to side and up and down, rocking motions). This type of action works on getting rid of painful trigger points, helps bring back flexibility, and promotes muscle pain relief. You yourself can control the amount of pressure the bumps apply to your body. The bumps are ergonomically placed less than 2" apart, so several of them simultaneously contact your body during most exercises. Use this to work on your quads, your lat muscles, your it band, your neck, upper back and lower back muscles.