[Physical 3-dimensional testing of the lumbar spine using the IsoStation B-200]

Low-back pain is not only one of the major medical problems, but the most common. Up to 80% of the population is expected to experience back pain at least once in their lifetime. The functional disability caused by LBP has a major influence on quality of life, as well as its economic aspects. Psychological and social factors are highly involved with LBP. Therefore any advance in objective assessment of LBP is of major importance. We present a relatively new system used for the past 2 years by our departments, the IsoStation B-200 (Isotechnologies Co., NC). This system enables simultaneous 3-D measurements of range of motion, speed of movement and torques in the lumbar back in a highly accurate and reproducible manner. The results are used to classify the status of LBP in terms of severity and disability. They enable us to assess quality of performance and to detect the "symptom magnification syndrome" (SMS), patients with non-physiologic complaints and behavior. We describe in detail the measurement protocol and the exact definitions and criteria used in the process of patient classification. Finally we present the results of our first 238 patients tested. A highly significant difference in almost all measured and calculated parameters was found between the patients with physiologic behavior and those with SMS or nonphysiological behavior. Findings related to all classifications are presented.