Dynaflex Bak-Ball Physical therapy tool can immediately relieve back pain and stiffness by exerting localized pressure on stiff joints Allows you to safely self-treat back pain Designed by an Olympic physiotherapist to match spine's anatomy Therapeutic force is delivered directly to most commonly painful regions of the spine; also improves posture Daily use can loosen stiff and painful spine, accelerate recovery from back injuries, and reduce chance of recurring back pain