title: Low-frequency magnetic field technology: quantifying spinal range of motion.
abstract: Reliability of a sensitive, noninvasive technique for quantifying spinal range of motion was assessed by investigators who measured lumbar mobility of 19 subjects with no history of low-back pain or spinal abnormalities. The measurement method used low-frequency, quasistatic magnetic dipole field and sensors which disturb this field in a precisely quantifiable manner. Sensors, affixed to the skin over T12 to L1 interspace and over the sacrum at the level of S1, were directly interfaced with an IBM PC-AT microcomputer, which was used for error-free collection and storage of data. Measurement results compared favorably to those obtained from the biplanar radiographic technique. Statistical analysis showed an extremely high degree of intraobserver and interobserver reliability. Additional advantages included simplicity and noninvasiveness. Overall, the magnetic field technique proved a significant advancement in clinically quantifying spinal mobility, allowing precise determination of impairment under American Medical Association guidelines.
authors.affiliation: Surf Medical Center, Torrance, CA 90505.
authors.forename: M L
authors.initials: ML
authors.lastname: Cohn
authors.forename: A F
authors.initials: AF
authors.lastname: Machado
authors.forename: S J
authors.initials: SJ
authors.lastname: Cohn
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D008159:Lumbar Vertebrae / Q000502:physiology*; D008280:Magnetics; D008297:Male; D008875:Middle Aged; D009068:Movement; D012016:Reference Values