The present invention relates to devices for providing support to the lower back. Specifically, it discloses an improved back support device featuring a removable and replaceable lumbar support system capable of reconfiguration to supply support, compression and/or gentle pressure to the lumbar area of the body. Different sized or shaped inserts can be used to accommodate therapy and training, and to customize the device for individuals of all body shapes and sizes. The device and method disclosed are safe and effective for both training and rehabilitation, and advance the field of orthopedic and ergonomic support devices.