Cut-off scores to indicate the hyperkyphosis and vertebral fracture The finding reported that there were 39 participants (40.63%) revealing the degree of Cobb angle more than 40 degrees. These participants had statistically significant longer distance using OBD and larger degree using Cobb's method than those without hyperkyphosis (p-value < 0.001, Table 10). In addition, the cut-off score of OBD was reported at least 7.40 cm (sensitivity 71.80%, specificity 73.70%, and AUC = 0.734) to indicate the thoracic hyperkyphosis (Table 11). Regarding the prevalence of vertebral fracture, there were 21 participants (21.88%) reporting by a radiologist. All of them had type of vertebral fracture as anterior wedge compression fracture. More than half of them had mild anterior wedge compression fracture (85.71%). Moreover, their Cobb angles were significantly greater than those without vertebral fracture (p-value = 0.009, Table 10). However, the OBD cannot indicated risk of vertebral fracture due to low level of AUC (Table 11).