Test-retest reliability of a photographic marker-based system for postural examination

BACKGROUND: The BHOHB system (Bhohb S.r.l., Italy) is a portable non-invasive photographic marker-based device for postural examination. OBJECTIVE: To assess the test-retest reliability of the BHOHB system and compare its reliability with an optoelectronic system (SMART-DX 700, BTS, Italy). METHODS: Thirty volunteers were instructed to stand upright with five markers on the spinous processes of C7, T6, T12, L3 and S1 vertebrae to define the dorsal kyphosis and lumbar lordosis (sagittal plane) angles. Three markers were placed on the great trochanter, apex of iliac crest and lateral condyle of the femur to detect pelvic tilt. Finally, to define angles between the acromion and the spinous processes (frontal plane), two markers were placed on the right and left acromion. Postural angles were recoded simultaneously with BHOHB and optoelectronic systems during two consecutive recording sessions. RESULTS: The BHOHB system revealed excellent reliability for all the angles (ICCs: 0.92-0.99, SEM: 0.78 degrees-3.33 degrees) as well as a shorter processing time compared to the optoelectronic system. Excellent reliability was also found for all the angles detected through the optoelectronic system (ICCs: 0.91-0.99, SEM: 0.84 degrees -2.80 degrees). CONCLUSION: The BHOHB system resulted as a reliable non-invasive and user-friendly device to monitor spinal posture, especially in subjects requiring repeat examinations.