VALIDITY OF 3 LUMBAR SAGITTAL MOTION MEASUREMENT METHODS - SURFACE INCLINOMETERS COMPARED WITH RADIOGRAPHS

Three surface methods for measuring lumbar sagittal motion (LSM) were tested for validity using radiographs as the ''gold standard'' referen ce. The three methods used were the Pleurimeter V double inclinometer, the carpenter double inclinometer, and the computerized sensor single inclinometer. ln this study, 30 volunteers were examined independentl y by three occupational health professionals. Each volunteer rotated t wice through three stations at which LSM was measured by each of the t hree methods, Radiographs were made during the first rotation. Predict ability of the skin marks of T12 and S1 for the corresponding bone mea sures was acceptable for one examiner, mixed for another, and unaccept able for a third. The intraclass correlation coefficients (ICCs) range d from 0.81 to 0.99 with half above the acceptable level of O.90. Howe ver, the skin marks and the bone measures showed a linear relationship for all examiners (r greater than or equal to 0.89). For flexion and extension, all ICCs between the radiograph and each surface method wer e far below O.90, indicating poor validity for each surface method, We concluded that skin placement of T12 and S1 has a linear relationship to bony landmarks, and that each of the tested surface methods does n ot validly measure LSM.