Towards monitoring lumbo-pelvic posture in real-life situations: concurrent validity of a novel posture monitor and a traditional laboratory-based motion analysis system.

Many factors are associated with low back pain (LBP), including provocative spinal postures. Consequently, lumbo-pelvic posture is commonly assessed in LBP patients. A novel wireless monitor (BodyGuard™) can monitor lumbo-pelvic sagittal plane movements reliably, and has demonstrated concurrent validity during non-functional tasks. This study evaluated the concurrent validity of this monitor during functional tasks, as a precursor to LBP field studies. Twelve painfree participants performed a series of postural tasks (in sitting and standing) three times. Simultaneous postural measurements were obtained by the wireless monitor and a laboratory-based system (CODA™). Postural measurements were strongly correlated (r(s) = 0.88, r(2) = 0.78). The mean difference observed was small (<10% lumbo-pelvic ROM), however some tasks displayed greater error. The results support the concurrent validity of the wireless monitor for analysing lumbo-pelvic posture during functional tasks. Specific limitations of the monitor for certain postural tasks were identified, and should be considered before implementation in future field studies.