Validation of a novel spinal posture monitor: comparison with digital videofluoroscopy

Abstract

The BodyGuard™ appears to be a valid method for analysing vertebral motion in the sagittal plane and is a promising tool for long-term monitoring of spinal postures in laboratory and clinical settings in people with low back pain.

The role of wearables in spinal posture analysis: a systematic review

“… More variable error rate in arbitrary position readings. O’Sullivan et al, 2012 [ 17 ] BodyGuard: strain gauge From spinous process of L3 to S2 calibrated to individual based on %ROM - correlation to digital fluoroscopy: sitting vs standing r 2 = 0.94 vs 0.88 Real-time biofeedback (auditory or visual) Validation of BodyGuard for analysis of vertebral motion in the sagittal plane ( n = 12) Slight and consistent underestimate of lumbopelvic flexion; validated method for use in laboratory and clinical settings. Outcome limitations: Further validation required for use in individuals with low back pain Bhattacharya et al, 1999 [ 18 ] Ergonomic dosimeter Trunk and upper dominant arm (housed in coveralls) - Output stratified into risk categories based on ROM magnitude No real-time feedback Validation of system to measure postural angles of torso and upper arm in sagittal plane ( n = 2) Reliable system for the continuous monitoring of postural data in carpenters on construction sites Selection bias: Small cohort not representative of general population No data on correlation to video data during scenarios Plamondon et al, 2007 [ 15 ] Hybrid system: two IMUs linked by potentiometer IMUs: 1: S1 (pelvic analysis) 2: T1 spinous process (thoracic flexion/lateral flexion and torsion) - Error in degrees: 2.7, 1.9 and 5.2 respectively No real-time feedback Validation of hybrid system for 3D measurement of trunk posture; analysis of utility of potentiometer to increase validity ( n = 6) Root mean square error less than 3 degrees for forward- and lateral-flexion; potentiometer required when magnetometer signals corrupted Comparability and outcome limitation: Error increased in long-duration dynamic tests (30 min) vs. short-duration (30 s) particularly without magnometer Faber et al, 2009 [ 37 ] MTx IMU System 1: sacrum 2: T9 3: movable (between 1 and 2) Peak error rate ¬5 degrees No real-time feedback Determination of the possibility and optimal location of a single sensor for trunk inclination measurement ( n = 10) Optimal inertial sensor location for trunk inclination measurement 25% of the distance from the midpoint between the PSISs to C7 and was hence different to each subject.…”

“…[ 16 ]. Other technologies used in posture monitoring wearables include: strain gauges; flex sensors; fibre-optic goniometers; inductive sensors; ergonomic dosimeters [ 17 – 21 ]. These devices are briefly explored in Table 1 , however at this stage are not validated for routine clinical use.…”

Reducing lumbar spine flexion using real-time biofeedback during patient handling tasks

“…Examples of movement-centred feedback uses include: correcting slouching behavior [65], adolescent scoliosis therapy [66], reducing warehouse working injury rates [67], Parkinson's disease therapy [68], nonspecific chronic low back pain therapy [69] and a video game designed to improve lifting technique [70]. Sensors used in these systems include mechanical switches [65], electromagnetic trackers [67], strain gauges [71], and accelerometers [72]. Feedback is provided with either auditory [65][66][67][68]72] or vibrotactile actuators [69].…”

A Validation Study of a Polymer Optical Fiber Sensor for Monitoring Lumbar Spine Movement

“…In addition, the relatively small sample size is a potential limitation in this study, as it was not based on the power calculation. However, it was considered to be consistent based on previous validation studies of similar devices [ 28 ].…”