Relation between Photogrammetry and Spinal Mouse for Sagittal Imbalance Assessment in Adolescents with Thoracic Kyphosis

The evaluation of postural alignment in childhood and adolescence is fundamental for
sports, health, and daily life activities. Spinal Mouse (SM) and photogrammetry (PG) are two of the
most debated tools in postural evaluation because choosing the proper instrument is also important
to avoid false or misleading data. This research aims to find out the best linear regression models
that could relate the analytic kyphosis measurements of the SM with one or more PG parameters
of body posture in adolescents with kyphotic posture. Thirty-four adolescents with structural and
non-structural kyphosis were analyzed (13.1  1.8 years; 1.59  0.13 m; 47.0  12.2 kg) using SM
and PG on the sagittal plane in a standing and forward-bending position, allowing us to measure
body vertical inclination, trunk flexion, and sacral inclination and hip position during bending. The
stepwise backward procedure was assessed to estimate the variability of the grade of inclination
of the spine and thoracic spine curvature with fixed upper and lower limits, evaluated with SM
during flexion. In both models, the PG angle between the horizontal line and a line connecting the
sacral endplate–C7 spinous process and the PG hip position were the best regressors (adjusted-R2
SM bend = 0.804, p < 0.001; adjusted-R2 SM fixed bending = 0.488, p < 0.001). Several Spinal Mouse
and photogrammetry parameters showed significant correlations, especially when the Spinal Mouse
measurements were taken when the adolescents were in the forward-bending position. Physicians
and kinesiologists may consider photogrammetry as a good method for spinal curve prediction.