Differences in standing and sitting postures of youth with idiopathic scoliosis from quantitative analysis of digital photographs

Postural habits and lifestyle factors associated with adolescent idiopathic scoliosis (AIS) in China: results from a big case-control study

BACKGROUND

Adolescent idiopathic scoliosis (AIS) is the most prevalent type of scoliosis affecting children between the ages of 10-16 years. However, risk factors for AIS, particularly the modifiable ones, are still largely unknown. This study aims to investigate the associations of lifestyle and social environment factors with AIS in Chinese schoolchildren.

METHODS

This is a matched case-control study based on survey data collected from school-based scoliosis screening program. We used conditional logistic regression models to describe the relative risk of AIS incidence for each variable in the analyses. To examine the independent effect of each factor on developing AIS, a multivariate conditional logistic regression was conducted and odds ratios (ORs) were adjusted for age and other significant variables.

RESULTS

Overall, 2538 participants from 49 schools were included in this study, comprising 1269 AIS cases and 1269 controls. Mean age of the study population was 13.4 years ± 1.06 (range 10-18). One thousand five hundred and fifty (61.1%) of the study subjects were girls. After adjusting for other significant factors, inappropriate desk heights, either too low (OR = 1.40, 95% CI 1.04-1.90) or too high (OR = 1.61, 95% CI 1.09-2.38), standing with anterior pelvic tilt (OR = 2.73, 95% CI 1.41-5.28), and sleeping on the right side (OR = 1.38, 95% CI 1.00-1.91), remained associated with elevated AIS risks. In contrast, sitting normally and classroom sitting positions change regularly were associated with lower odds of AIS. The adjusted ORs were 0.69 (95% CI 0.50-0.96) for sitting normally, and 0.72 (95% CI 0.53-0.98) for sitting positions change.

CONCLUSIONS

This is the first study to address the associations between desk heights and AIS and showed inappropriate desk heights were related to increased AIS risks. To protect school children from developing AIS, stakeholders are advised to consider introducing height-adjustable desks in the class, changing students' sitting positions in the classroom on a regular basis, and implementing educational programs to help students maintain correct sitting postures.

Effects of a postural cueing for head and neck posture on lumbar lordosis angles in healthy young and older adults: a preliminary study

Background

Postural rehabilitation plays an important role in the treatment of non-specific low back pain. Although pelvic inclination has been widely used to improve lumbar lordosis, the effect of cervical anterior inclination on lumbar lordosis in young and older adults in sitting and standing posture is still unclear. This preliminary study was designed to examine the influence of changing the cervical anterior angle on the lumbar lordosis angle, through alterations of the head position under the natural sitting and standing conditions, aiming to provide a basis for establishing a new postural rehabilitation strategy.

Methods

Thirty-six young (24.0 ± 2.2 years, 14 females and 22 males) and 38 older (68.4 ± 5.9 years, 36 females and 2 males) healthy adults participated in this study. The four spinal regional angles—cervical anterior angle, thoracic kyphosis angle, lumbar lordosis angle, and pelvic forward inclination angle, were measured in standing and relaxed sitting postures to determine the effects of a postural cueing for the head and neck posture, “inclining head backward and performing chin tuck,” on lumbar lordosis angle.

Results

In the standing posture, the pelvic forward inclination angle in the older adult group was significantly smaller (P < 0.001, by ANOVA) than that in the young adult group and increased significantly (P < 0.001) in response to the postural cueing. In addition, the thoracic kyphosis angle in the standing (P = 0.001) and sitting (P = 0.003) positions was significantly reduced in response to the postural cueing. However, the lumbar lordosis angle in response to the postural cueing increased significantly in both the standing position (P < 0.001) and sitting position (P < 0.001).

Conclusion

The results suggest that increasing the cervical anterior angle can increase the lumbar lordosis angle, and the cervical anterior inclination can be used as an alternative to pelvic forward inclination to improve the lumbar lordosis angle. Furthermore, the change in head and neck posture can reduce the thoracic kyphosis angle, making it possible to establish a new noninvasive body posture rehabilitation strategy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13018-022-03090-9.

Test-retest reliability of posture measurements in adolescents with idiopathic scoliosis

BACKGROUND CONTEXT

Posture changes are a major consequence of idiopathic scoliosis (IS). Posture changes can lead to psychosocial and physical impairments in adolescents with IS. Therefore, it is important to assess posture, but the test-retest reliability of posture measurements still remains unknown in this population.

PURPOSE

The primary objective of the present study was to determine the test-retest reliability of 25 head and trunk posture indices using the Clinical Photographic Postural Assessment Tool (CPPAT) in adolescents with IS. The secondary objective was to determine the standard error of measurement and the minimal detectable change.

STUDY DESIGN/SETTING

This is a prospective test-retest reliability study carried out at two tertiary university hospital centers.

PATIENTS SAMPLE

Forty-one adolescents with IS, aged 10-16 years old with curves 10°-45° and treated by medical intervention, were recruited.

METHODS

Two posture assessments were done using the CPPAT 5-10 days apart following a standardized procedure. Photographs were analyzed with the CPPAT software by digitizing reference landmarks placed on the participant by a physiotherapist evaluator. Generalizability theory was used to obtain a coefficient of dependability, standard error of measurement, and the minimal detectable change at 90% confidence interval.

RESULTS

Fourteen of 25 posture indices had a good reliability (ϕ≥0.78), 10 had moderate reliability (ϕ=0.55-0.74), and 1 had poor reliability (ϕ=0.45). The most reliable posture indices were waist angle asymmetry (ϕ=0.93), right waist angle (ϕ=0.91), and frontal trunk list (ϕ=0.92). Right sagittal trunk list was the least reliable posture index (ϕ=0.45). The MDC₉₀ values ranged from 2.6 to 10.3° for angular measurements and from 8.4 to 35.1 mm for linear measurements.

CONCLUSIONS

The present study demonstrates that most posture indices, especially the trunk posture indices, are reproducible in time among adolescents with IS and provides reference values. Clinicians and researchers can use these reference values to assess change in posture over time attributable to treatment effectiveness.

The acceptance of the clinical photographic posture assessment tool (CPPAT)

BACKGROUND

There is a lack of evidence-based quantitative clinical methods to adequately assess posture. Our team developed a clinical photographic posture assessment tool (CPPAT) and implemented this tool in clinical practice to standardize posture assessment. The objectives were to determine the level of acceptance of the CPPAT and to document predictors as well as facilitators of and barriers to the acceptance of this tool by clinicians doing posture re-education.

METHODS

This is a prospective study focussing on technology acceptance. Thirty-two clinician participants (physical therapists and sport therapists) received a 3-5 h training workshop explaining how to use the CPPAT. Over a three-month trial, they recorded time-on-task for a complete posture evaluation (photo - and photo-processing). Subsequently, participants rated their acceptance of the tool and commented on facilitators and barriers of the clinical method.

RESULTS

Twenty-three clinician participants completed the trial. They took 22 (mean) ± 10 min (SD) for photo acquisition and 36 min ± 19 min for photo-processing. Acceptance of the CPPAT was high. Perceived ease of use was an indirect predictor of intention to use, mediated by perceived usefulness. Analysis time was an indirect predictor, mediated by perceived usefulness, and a marginally significant direct predictor. Principal facilitators were objective measurements, visualization, utility, and ease of use. Barriers were time to do a complete analysis of posture, quality of human-computer interaction, non-automation of posture index calculation and photo transfer, and lack of versatility.

CONCLUSION

The CPPAT is perceived as useful and easy to use by clinicians and may facilitate the quantitative analysis of posture. Adapting the user-interface and functionality to quantify posture may facilitate a wider adoption of the tool.

Global postural re-education in pediatric idiopathic scoliosis: a biomechanical modeling and analysis of curve reduction during active and assisted self-correction

Background

Global postural re-education (GPR) is a physiotherapy treatment approach for pediatric idiopathic scoliosis (IS), where the physiotherapist qualitatively assesses scoliotic curvature reduction potential (with a manual correction) and patient’s ability to self-correct (self-correction). To the author’s knowledge, there are no studies regarding GPR applied to IS, hence there is a need to better understand the biomechanics of GPR curve reduction postures. The objective was to biomechanically and quantitatively evaluate those two re-education corrections using a computer model combined with experimental testing.

Methods

Finite elements models of 16 patients with IS (10.5–15.4 years old, average Cobb angle of 33°) where built from surface scans and 3D radiographic reconstructions taken in normal standing and self-corrected postures. The forces applied with the therapist’s hands over the trunk during manual correction were recorded and used in the FEM to simulate this posture. Self-correction was simulated by moving the thoracic and lumbar apical vertebrae from their presenting position to their self-corrected position as seen on radiographs. A stiffness index was defined for each posture as the global force required to stay in the posture divided by the thoracic curve reduction (force/Cobb angle reduction).

Results

The average force applied by the therapist during manual correction was 31 N and resulted in a simulated average reduction of 26% (p < 0.05), while kyphosis slightly increased and lordosis remained unchanged. The actual self-correction reduced the thoracic curve by an average of 33% (p < 0.05), while the lumbar curve remained unchanged. The thoracic kyphosis and lumbar lordosis were reduced on average by 6° and 5° (p < 0.05). Self-correction simulations correlated with actual self-correction (r = 0.9).

Conclusions

This study allowed quantification of thoracic curve reducibility obtained by external forces applications as well as patient’s capacity to self-correct their posture, two corrections commonly used in the GPR approach.

Two-dimensional digital photography for child body posture evaluation: standardized technique, reliable parameters and normative data for age 7-10 years

BACKGROUND

Digital photogrammetry provides measurements of body angles or distances which allow for quantitative posture assessment with or without the use of external markers. It is becoming an increasingly popular tool for the assessment of the musculoskeletal system. The aim of this paper is to present a structured method for the analysis of posture and its changes using a standardized digital photography technique.

MATERIAL AND METHODS

The purpose of the study was twofold. The first one comprised 91 children (44 girls and 47 boys) aged 7-10 (8.2 ± 1.0), i.e., students of primary school, and its aim was to develop the photographic method, choose the quantitative parameters, and determine the intraobserver reliability (repeatability) along with the interobserver reliability (reproducibility) measurements in sagittal plane using digital photography, as well as to compare the Rippstein plurimeter and digital photography measurements. The second one involved 7782 children (3804 girls, 3978 boys) aged 7-10 (8.4 ± 0.5), who underwent digital photography postural screening. The methods consisted in measuring and calculating selected parameters, establishing the normal ranges of photographic parameters, presenting percentile charts, as well as noticing common pitfalls and possible sources of errors in digital photography.

RESULTS

A standardized procedure for the photographic evaluation of child body posture was presented. The photographic measurements revealed very good intra- and inter-rater reliability regarding the five sagittal parameters and good reliability performed against Rippstein plurimeter measurements. The parameters displayed insignificant variability over time. Normative data were calculated based on photographic assessment, while the percentile charts were provided to serve as reference values. The technical errors observed during photogrammetry are carefully discussed in this article.

CONCLUSIONS

Technical developments are allowed for the regular use of digital photogrammetry in body posture assessment. Specific child positioning (described above) enables us to avoid incidentally modified posture. Image registration is simple, quick, harmless, and cost-effective. The semi-automatic image analysis, together with the normal values and percentile charts, makes the technique reliable in terms of child's posture documentation and corrective therapy effects' monitoring.

Validity and reliability of photographic measures to evaluate waistline asymmetry in idiopathic scoliosis

OBJECTIVE

Evaluate the relationship between radiological, clinical and perceived waistline asymmetry (WLA) in a sample of idiopathic scoliosis (IS) patients.

METHODS

77 patients were included (mean age 20.3 years; 85 % women). We obtained a full X-ray of the spine and back clinical photography for all patients. On photographs, waist height angle (WHA), right/left waist angles (WA) and right/left waistline distance ratio were measured. SRS22, Trunk Appearance Perception Scale (TAPS) and Spinal Appearance Questinnaire (SAQ) questionnaires were also completed. The intra and inter-observer reliability of each photographic measure was assessed. A correlation analysis between all variables was done using Pearson Correlations Coefficient.

RESULTS

All measures reported have excellent intra- and inter-observer (ICC ≥0.8) reliability. A significant correlation was found between WHA and Cobb angle, mainly with Main Thoracic (MT) (r = -0.56). Right and left waist angles, and especially the difference between them (RLWAD), is related to the thoracolumbar/lumbar (TLL) curve. We have found a significant correlation between RLWAD and TLL curve magnitude (r = -0.54) and with the inclination of the lower end vertebra (LEV) (r = 0.74). Only WHA has a significant, but poor correlation (r ≅ 0.3) with trunk perception scales (TAPS and SAQ). No other significant correlations were found between WLA measures and patient related outcome scores.

CONCLUSION

WLA measures proposed in this article are reliable tools to assess WLA. We have found a significant correlation between clinical WLA and skeletal deformity (Cobb angle). WHA is related with MT curve while the RLWAD depends on the TLL curve magnitude and its LEV. We have also found a significant relation between WHA and the patient's perception of the deformity. It seems that WLA is a cosmetic concern to take into account in clinical evaluation of IS patients.

Photogrammetry as a tool for the postural evaluation of the spine: A systematic review

AIM: To evaluate the use of photogrammetry and identify the mathematical procedures applied when evaluating spinal posture.

METHODS: A systematic search using keywords was conducted in the PubMed, EMBASE, Scopus, Science and Medicine^® databases. The following inclusion criteria adopted were: (1) the use of photogrammetry as a method to evaluate spinal posture; (2) evaluations of spinal curvature in the sagittal and/or frontal plane; (3) studies published within the last three decades; and (4) written entirely in English. The exclusion criteria were: (1) studies which objective involved the verification of some aspect of validation of instruments; (2) studies published as abstracts and those published in scientific events; and (3) studies using evaluation of the anteriorization of the head to determine the angular positioning of the cervical spine. The articles in this review were included and evaluated for their methodological quality, based on the Downs and Black scale, by two independent reviewers.

RESULTS: Initially, 1758 articles were found, 76 of which were included upon reading the full texts and 29 were included in accordance with the predetermined criteria. In addition, after analyzing the references in those articles, a further six articles were selected, so that 35 articles were included in this review. This systematic review revealed that the photogrammetry has been using in observational studies. Furthermore, it was also found that, although the data collection methodologies are similar across the studies, in relation to aspects of data analysis, the methodologies are very different, especially regarding the mathematical routines employed to support different postural evaluation software.

CONCLUSION: With photogrammetry, the aim of the assessment, whether it is for clinical, research or collective health purposes, must be considered when choosing which protocol to use to evaluate spinal posture.

Freehand three-dimensional ultrasound system for assessment of scoliosis

Background/Objective

Standing radiograph with Cobb's method is routinely used to diagnose scoliosis, a medical condition defined as a lateral spine curvature > 10° with concordant vertebral rotation. However, radiation hazard and two-dimensional (2-D) viewing of 3-D anatomy restrict the application of radiograph in scoliosis examination.

Methods

In this study, a freehand 3-D ultrasound system was developed for the radiation-free assessment of scoliosis. Bony landmarks of the spine were manually extracted from a series of ultrasound images with their spatial information recorded to form a 3-D spine model for measuring its curvature. To validate its feasibility, in vivo measurements were conducted in 28 volunteers (age: 28.0 ± 13.0 years, 9 males and 19 females). A significant linear correlation (R² = 0.86; p < 0.001) was found between the spine curvatures as measured by Cobb's method and the 3-D ultrasound imaging with transverse process and superior articular process as landmarks. The intra- and interobserver tests indicated that the proposed method is repeatable.

Results

The 3-D ultrasound method using bony landmarks tended to underestimate the deformity, and a proper scaling is required. Nevertheless, this study demonstrated the feasibility of the freehand 3-D ultrasound system to assess scoliosis in the standing posture with the proposed methods and 3-D spine profile.

Conclusion

Further studies are required to understand the variations that exist between the ultrasound and radiograph results with a larger number of volunteers, and to demonstrate its potential clinical applications for monitoring of scoliosis patients. Through further clinical trials and development, the reported 3-D ultrasound imaging system can potentially be used for scoliosis mass screening and frequent monitoring of progress and treatment outcome because of its radiation-free and easy accessibility feature.