Postural deformities often manifest themselves in a sagittal imbalance and an asymmetric morphology of the torso. As a novel topographic method, torsobarography assesses the morphology of the back by analysing pressure distribution along the torso in a lying position. At torsobarography’s core is a capacitive pressure sensor array. To evaluate its feasibility as a diagnostic tool, the reproducibility of the system and extracted anatomical associated parameters were evaluated on 40 subjects. Landmarks and reference distances were identified within the pressure images. The examined parameters describe the shape of the spine, various structures of the trunk symmetry, such as the scapulae, and the pelvic posture. The results showed that the localisation of the different structures performs with a good (ICC > 0.75) to excellent (ICC > 0.90) reliability. In particular, parameters for approximating the sagittal spine shape were reliably reproduced (ICC > 0.83). Lower reliability was observed for asymmetry parameters, which can be related to the low variability within the subject group. Nonetheless, the reliability levels of selected parameters are comparable to commercial systems. This study demonstrates the substantial potential of torsobarography at its current stage for reliable posture analysis and may pave the way as an early detection system for postural deformities.

The soft tissues of residual limb amputees are subject to large volume fluctuations over the course of a day. Volume fluctuations in residual limbs can lead to local pressure marks, causing discomfort, pain and rejection of prostheses. Existing methods for measuring interface stress encounter several limitations. A major problem is that the measurement instrumentation is applied in the sensitive interface between the prosthesis and residual limb. This paper presents the principle investigation of a non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputees based on experimentally obtained vibrational data. The proposed approach is based on changes in the dynamical behaviour detectable at the outer surface of prostheses; thus, the described interface is not affected. Based on the experimental investigations shown and the derived results, it can be concluded that structural dynamic measurements are a promising non-intrusive technique to evaluate the fit of orthopaedic prosthesis sockets in transfemoral amputee patients. The obtained resonance frequency changes of 2% are a good indicator of successful applicabilityas these changes can be detected without the need for complex measurement devices.

Adolescent idiopathic scoliosis (AIS) is treated with various forms of conservative care or surgery, depending on the degree of severity. When AIS is detected early, it can be monitored and initially treated with reduced invasiveness to prevent further progression. AIS manifests itself through deformations of the trunk, which are mostly identified as asymmetries in manual clinical examination. Torsobarography is a new pressure-based surface topographic system for posture analysis and evaluates such associated morphologic asymmetries. The aim of this study is to investigate the diagnostic validity of torsobarography by examining correlation of extracted torsobarographic indices with the Cobb angle and its ability to differentiate between different severities of scoliosis: no scoliosis, mild scoliosis, and moderate scoliosis. A total of 87 subjects (51 females and 36 males) were examined with torsobarography. Six torsobarographic indices were calculated for all subjects: torsobarography angle (TBA), sagittal imbalance index (SII), torso asymmetry index (TAI), shoulder asymmetry angle (SAA), waist asymmetry angle (WAA), and pelvis asymmetry Angle (PAA). These indices were correlated with the Cobb angle, and the differences between severities were statistically analyzed. Three out of six indices (TBA, TAI, and WAA) were able to significantly distinguish between mild and moderate scoliosis. Additionally, those indices showed moderate correlation ($\rho$ = 0.37–0.50) with the Cobb angle measurements. The WAA was the only statistically significant index capable of differentiating between no scoliosis and moderate scoliosis. This study is the first to demonstrate that torsobarography can distinguish between different severities of scoliosis and thus identify a scoliotic deformity that requires bracing over monitoring.

Adolescent idiopathic scoliosis (AIS) is treated with various forms of conservative care or surgery, depending on the degree of severity. When AIS is detected early, it can be monitored and initially treated with reduced invasiveness to prevent further progression. AIS manifests itself through deformations of the trunk, which are mostly identified as asymmetries in the manual clinical examination. Torsobarography is a new pressure-based surface topographic system for posture analysis and evaluates such associated morphologic asymmetries. The aim of the study is to investigate the diagnostic validity of torsobarography by examining correlation of extracted torsobarographic indices with the Cobb angle and its ability to differentiate between different severities of scoliosis: no scoliosis, mild scoliosis and moderate scoliosis. A total of 87 subjects (51 females, 36 males) were examined with torsobarography. Six torsobarographic indices were calculated for all subjects: torsobarography angle (TBA), sagittal imbalance index (SII), torso asymmetry index (TAI), shoulder asymmetry angle (SAA), waist asymmetry angle (WAA) and pelvis asymmetry Angle (PAA). These indices were correlated with the Cobb angle and the differences between severities were statistically analyzed. Three out of six indices (TBA, TAI, WAA) were able to significantly distinguish between mild and moderate scoliosis. Additionally, those indices showed moderate correlation ("ρ = 0.37–0.50" ) with the Cobb angle measurements. The WAA was the only statistically significant index capable of differentiating between no scoliosis and moderate scoliosis. This study is the first to demonstrate that torsobarography can distinguish between different severities of scoliosis and thus identify a scoliotic deformity that requires bracing over monitoring.

Purpose: A healthy posture is characterized by symmetric features like equal shoulder height, a straight spinous process line and equally-sized waist triangles. Deviations suggest spinal disorders, among them adolescent idiopathic scoliosis (AIS), a three-dimensional spinal curvature requiring timely treatment. AIS screenings are debated among the scientific community. This study proposes two symmetry-sensitive convolutional neural networks (CNNs) to identify asymmetries in videorasterstereographic back curvature images to classify AIS. Methods: A total of 1444 videorasterstereographic measurements were collected from individuals (11 ± 2.4 years), among them 355 with AIS, 306 with other spinal deformities and 783 with healthy posture. Two types of curvature images, Mean and Gauss, were compared using a VGG16 network and a two-channel CNN based on DeepSymNet. The latter analyzes left and right side of the torso image separately, then merges the results and identifies asymmetries. Results: Both models achieved accuracies between 0.768 and 0.801 during validation, the accuracy of the test set of the tuned DeepSymNet (five repeated trials) was 0.744 ± 0.014, specificity was 0.748 ± 0.025, sensitivity 0.726 ± 0.044 and PPV 0.417 ± 0.013. The equal performances show models were able to learn symmetry, making both suitable for training videorasterstereographic images. The main benefit and greatest challenge was the dataset diversity, which incorporated a variety of postural conditions, confounding AIS features. Conclusion: Adapting CNNs to include symmetry analysis could be an improvement to other known applications of deep learning in spinal deformity analysis. Refining the dataset to incorporate more mild cases could enhance the performance of DeepSymNet in particular. With these modifications, DeepSymNet as well as VGG16 are promising approaches for future AIS screenings.