The present invention provides a vertebral implant comprising a wall forming two short sides (100, 101) and two elongated sides (102, 103) to define a generally elongated structure having a passageway (106) therethrough. At least one of the two elongated sides is resiliently compressible into the passageway, or resiliently expandable away from the passageway, under a force applied to the implant by movement of the spine into which the implant is placed. This resilient opposition to forces in the spine causes the device to want to return to its at-rest position, thereby aiding the spine in its return to a normal position after movement is relaxed, thereby aiding proper spine alignment. Preferably, the device comprises a flexible body having a generally loop-shaped configuration defined by the wall, wherein the wall material and thickness is selected so that the device has appropriate degrees of flexibility and strength.