Background: Interactions within the musculoskeletal system have been investigated and confirmed in numerous studies.
Objectives: Since there are no standard values for the posture of healthy persons, this study attempts to define reference values for the upper body posture in healthy men.
Material and methods: A 3-dimensional back scan was performed to quantify the upper back posture while habitually standing. Tolerance regions for habitual posture were calculated, including the upper and lower limit for 95% of all values. Furthermore, the left and right limit of the confidence interval (CI) was carried out. Group differences were tested by using the t-test or the Wilcoxon-Mann-Whitney U test.
Results: Height, weight and body mass index (BMI) of the participants were comparable to those of the average young German males. The spinal column was marginally twisted to the right. The spinal curves, defined by the thoracic or lumbar flexion angle, and the kyphosis and lordosis angle, indicated that the angle in the thoracic spine area was larger than that in the lumbar region. Consequently, a more kyphotic posture was observed in the sagittal plane. The habitual posture was slightly scoliotic, with a rotational component (scapular depression left, right scapula marginally located more dorsally, high state of pelvic left, iliac left further rotated posteriorly and simultaneously tilted further ventrally). No significant difference between right and left-handed persons could be proven.
Conclusions: Video raster stereography is a suitable method to measure the 3-dimensional back surface. Using this method for healthy young men, we observed that they had an almost ideally balanced posture with minimal ventral body inclination and a marginal scoliotic deviation. The normal values allow a better comparison of data between different studies of body posture.
Keywords: back scan; confidence interval; male subjects; standard value; tolerance value.