Mobility is just another word for movement. In the case of the spine, there are six different motions involved. These include flexion (bending forward), extension (bending backward), sidebending (right and left), and rotation or twisting (right and left).
Total motion of all six directions reflect overall spinal mobility. But each individual spinal segment can also be assessed for mobility. Special tests can be done by the therapist to identify each segment as normal, hypomobile, or hypermobile. Hypomobile refers to a loss of motion. Hypermobile is a state of increased motion.
There is still quite a bit of debate over the concept of normal. What one examiner feels as normal may be labeled as hypomobile or hypermobile by someone else. Studies are underway to help therapists accurately identify spinal segments that fall into each of these three categories.
Dynamic MRIs are being used to measure the actual motion in the spine. These figures are compared with the therapist’s clinical judgment. A recent study done at USC (California) showed that spinal mobility testing seems to be most accurate in finding hypomobile segments. Hypermobile are more difficult to detect.