Common Foam Rollers Compress Soft Tissue
Physical therapists, trainers, and athletes use foam rollers to relieve muscular pain and tightness (often called "adhesions", "knots", or "trigger points"). But 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 RumbleRoller was created to perform this therapy more effectively