This invention is an implantable device that enables non-invasive post-operative adjustment of the motion dynamics between two members of the human skeletal system. It may be used for dynamic stabilization of the spine. This device includes: a flowable substance a reservoir implanted into the human body that contains this flowable substance wherein movement of moving portions of this reservoir causes the flowable substance to flow and an energy-transducing mechanism wherein this mechanism transduces energy from a flow of the flowable substance into changes in the motion dynamics between the two members of the human skeletal system. This device may be used for: (1) non-invasive post-implantation customization of the device to reduce back pain for a particular patient (2) non-invasive gradual adjustment of the device to correct spinal deformities and (3) real-time adjustment to optimize spinal motion dynamics as the patent engages in different activities.
