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

Abstract

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.

Keywords: Digital photography; Normative data; Percentile charts; Photogrammetry; Primary school children; Standardization.

Fig. 1

Anatomical points marked on the body

Fig. 2

a–j Standardized positions for posture photogrammetry

Fig. 3

Photographic documentation of trunk rotation/trunk inclination deformity revealed during Adams’ forward bending test (left to right—progressive forward bending)

Fig. 4

Feet positioning for posture photographic evaluation: a front view, b lateral left view, c back view, and d lateral right view

Fig. 5

Child’s posture taken for sagittal plane assessment: a spontaneous standing posture, b “actively corrected posture” in this child reveals backward trunk hyperextension which should be avoided; such image points out the importance of children education in what the correct human body posture consists of

Fig. 6

Diagram illustrating the measurements of ATSI Index

Fig. 7

Diagram illustrating the measurements of POTSI Index

Fig. 8

a Diagram illustrating the measurements of TFA. b Diagram illustrating the measurements of TCA

Fig. 9

a Diagram illustrating the measurements of SS. b Diagram illustrating the measurements of LL. c Diagram illustrating the measurements of TK. d Diagram illustrating the measurements of CI. e Diagram illustrating the measurements of HP

Fig. 10

a Diagram illustrating the measurements of SPT. b Diagram illustrating the measurements of TA. c Diagram illustrating the measurements of AA. d Diagram illustrating the measurements of EA

Fig. 11

SCODIAC printscreen images illustrating coronal and sagittal plane parameters

Fig. 12

Areas of application of the Rippstein plurimeter to the patient’s spine: a lumbo-sacral junction, b thoraco-lumbar junction, and c cervico-thoracic junction. The angular parameters are calculated as the differences between the two positions: lumbar lordosis = a, b; thoracic kyphosis = b, c

Fig. 13

Positioning of the child during photographic documentation of front view: a zero time, b after 1 h, and c after 1 week

Fig. 14

Positioning of the child during photographic documentation of back view: a zero time, b after 1 h, and c after 1 week

Fig. 15

Technical error—protraction of the shoulders

Fig. 16

Technical error—incorrect head position and/or gaze direction

Fig. 17

Technical error—lack of spontaneous relaxed posture

Fig. 18

Technical error—body contours covered by hair

Fig. 19

Technical error—gluteal cleft upper contour covered by underpants

Fig. 20

Technical error—the trunk obscured by bra or swimsuit

Fig. 21

Technical error—one-leg standing

Fig. 22

Technical error—incorrect feet position unparalleled

Fig. 23

Technical error—digital camera not leveled

Fig. 24

Technical error—limited communication with child

Fig. 25

Technical error—photo taken without proper focusing

Fig. 26

a–b Photographic assessment as proposed by Canales et al. in 2010 ([69], reprinted by permission)

Fig. 27

Photographic assessment as proposed by Cerutto et al. in 2012 ([70], reprinted by permission)

Fig. 28

Photographic assessment as proposed by Pausić et al. in 2010 ([71], reprinted by permission)

Fig. 29

a–d Photographic assessment as proposed by Penha et al. in 2009 ([8], reprinted by permission)

Fig. 30

Photographic assessment as proposed by Ruivo et al. in 2015 ([72], reprinted by permission)

Fig. 31

Photographic assessment as proposed by Sacco et al. in 2007 ([73], reprinted by permission)

Fig. 32

Photographic assessment as proposed by Canhadas et al. in 2009 ([74], reprinted by permission)

Fig. 33

a–c Photographic assessment as proposed by Matamalas et al. in 2016 ([75], reprinted by permission)

Fig. 34

Photographic assessment as proposed by Matamalas et al. in 2014 ([76], reprinted by permission)