The clinical assessment of Chronic Low Back Pain (CLBP) is usually undertaken at a single time point at clinic rather than through continuous monitoring. To address this, a wearable prototype sensor to monitor motion of the lumbar spine and pelvis has been developed. The system devised was based on inertial sensor technology combined with wireless Body Sensor Network (BSN) platform. This was tested on 16 healthy volunteers for ten common movements (including sit to stand, lifting, walking, and stairs) with results validated by optical tracking. Preliminary findings suggest good agreement between the optical tracker and device with mean average orientation error (°) ranging from 0.1 ± 2.3 to 4.2 ± 2.6. The sensor repeatability errors range from 0 to 4° while subject movement variability ranged from 4% to 14%. Parameters of angular motion suggest greater movement of the lumbar spine compared to the pelvis with mean velocities (°/s) for lumbar spine ranging from 15.3 to 74.13 and pelvis ranging from 5.6 to 40.74. Further analysis revealed the extent to which the pelvis was engaged, as a proportion of the total movement. This demonstrated that the pelvis underwent smooth transitions from low (0.02), moderate (0.4) to high (0.99) use during different movement phases.Background
Sensor Development, Testing and Results