Reliability of the DIERS Formetric 4D Spine Shape Parameters in Adults without Postural Deformities

Abstract

The DIERS formetric 4D provides a safe method to monitor and track the progression of postural deformities over time. However, further evaluation of reliability is necessary. Reference values are also needed to indicate postural change. The current study examined the reliability of spine shape parameters produced by the formetric 4D in adults without postural abnormalities and established reference values to determine when real change occurs. Thirty participants were scanned during 1 week. Intraclass correlation coefficients (ICCs) were calculated for 40 spine shape parameters for scans with participants stationary between scans, scans with repositioning between scans, and between days. Within-day and between-day standard error of measurement (SEM), absolute relative SEM, and smallest detectable change (SDC) were reported. ICC for stationary scans was excellent for 29 parameters, good for 10 parameters, and fair for 1 parameter. With repositioning, ICC was excellent for 27 parameters, good for 12 parameters, and fair for 1 parameter. Between days, ICC was excellent for 26 parameters, good for 10 parameters, and fair for 4 parameters. Within-day SEM% was greater than 10% for 6 parameters. Within-day SDC ranged from 1.80 to 25.03 units for a single scan and from 0.97 to 17.93 units for 6 scans. Between-day SEM% was greater than 10% for 9 parameters. Between-day SDC ranged from 1.44 to 28.24 units for a single scan and from 1.05 to 22.2 units for 6 scans. Thirty-six of the 40 spine shape parameters from the DIERS formetric 4D reliably distinguished between participants over time. Reference values were established that can be used to track patient postural change over time. Future research should investigate the clinical relevance of these 40 spine shape parameters and determine when a clinically important change in posture occurs.

Evaluation of 3D Vertebral and Pelvic Position by Surface Topography in Asymptomatic Females: Presentation of Normative Reference Data

“…The global parameters for the EG and both subgroups are shown for each of the three planes in Table 2, along with comparable values from other studies (10)(11)(12)(13)(14) in Table 2. Degenhardt, et al [10]; n = 30 women and men, 30.2 ± 9.8 years; Degenhardt, et al [11]; n = 29 women and men, 30.1 ± 10.1 years; Schröder et al [12], n = 89 women, 26.4 ± 4.5 years; Hamm [13] and Michalik et al [14], n = 56, women, 23.6 ± 2.0 years…”

“…In the CP, the mean trunk values of the EG were negative, which meant that the trunk was slightly tilted to the left (-1.9mm ± 8.9). The results of a different group (10,11) were positive, but regarding the comparable relatively high SDs (1.0mm ± 7.2, 1.3mm ± 5.6) the differences diminish. However, further research is warranted to examine whether groups differ by handedness, or other parameters, that could explain the high SD.…”

“…Recent literature offers limited data describing the relationship of vertebral body positions and upright physiologic posture of asymptomatic adults. (10)(11)(12)(13)(14) Additionally, the literature only describes global spinal relationships, for example thoracic kyphosis (TK) and lumbar lordosis (LL), but is lacking detailed data on individual vertebral segments. Currently, this technology is mainly used in scoliotic patients, who are predominantly female.…”

“…Global parameters (mean ± SD) and Literature review comparison in coronal, sagittal, and transversal plane of entire group (EG) and their p-, t-values and Cohen's d. *: p < 0.05; parameters of the younger (YG) and older group (OG) and their p-values; †: Parameter not clearly assigned (compare Discussion), ‡: Uncertain value (compare Discussion) Degenhardt, et al[10]; n = 30 women and men, 30.2 ± 9.8 years; Degenhardt, et al[11]; n = 29 women and men, 30.1 ± 10.1 years; Schröder et al[12], n = 89 women, 26.4 ± 4.5 years; Hamm[13] and Michalik et al[14], n = 56, women, 23.6 ± 2.…”

Evaluation of the association between postural control and sagittal curvature of the spine

“…The DIERS formetric 4D system (DIERS International Gmbh, Schlangenbad, Germany) was used to assess posture [ 36 – 37 ]. Using rasterstereography, the DIERS formetric 4D device allows for photogrammetric video recording of the subject’s back surface.…”