Photographic measurement of upper-body sitting posture of high school students: a reliability and validity study

Sjan-Mari van Niekerk, Quinette Louw, Christopher Vaughan, Karen Grimmer-Somers, Kristiaan Schreve, Sjan-Mari van Niekerk, Quinette Louw, Christopher Vaughan, Karen Grimmer-Somers, Kristiaan Schreve

Abstract

Background: All the reported measures of sitting posture, as well as photographs, have one flaw, as these measures are external to the body. These measures use calculations from external bony landmarks to estimate spinal posture, on the understanding that what is being measured externally reflects the shape, health and performance of structures of the underlying spine. Without a comparative measure of the relative position of the structures of the spine, the validity of any external spinal posture measure cannot be established. This paper reports on a study which tests the validity of photographs to measure adolescent sitting posture.

Methods: The study was conducted in a laboratory at the Department of Human Biology, University of Cape Town. A random sample of 40 adolescents were recruited from the Cape metropolitan schools, to detect differences of three degrees or more between the repeated measures of upright, normal or slouched posture (photographs) and between the posture photographs and LODOX measures. Eligible participants were healthy male and female subjects aged 15 or 16 years old, in Grade 10, and who were undertaking Computer or Computype studies at their schools. Two posture measurement tools were used in the study, namely: Photographs were taken using the Photographic Posture Analysis Method (PPAM) and Radiographs were taken using the LODOX (LODOX (Pty) Ltd) system. Subjects' posture was assessed in simulated computer workstations. The following angles were measured: the sagittal head angle, cervical angle, protraction/retraction angle, arm angle and the thoracic angle.

Results: Data from 39 subjects (19 males, 20 females) was used for analysis (17 15-year-olds (7 boys and 10 girls), 22 16-year-olds (12 boys and 10 girls)). All but one photographic angle showed moderate to good correlation with the LODOX angles (Pearson r values 0.67-0.95) with the exception being the shoulder protraction/retraction angle Pearson r values. Bland Altman limits of agreement illustrated a slight bias for all angles. The reliability study findings from repeated photographs demonstrated moderate to good correlation of all angles (ICC values 0.78-0.99).

Conclusion: The findings of this study suggest that photographs provide valid and reliable indicators of the position of the underlying spine in sitting. Clinically it is important to know whether a patient is showing true progression in relation to a postural intervention. Based on the results of this study, the PPAM can be used in practice as a valid measure of sitting posture.

Figures

Figure 1
Figure 1
Data collection procedure for each subject (reliability and validity studies).
Figure 2
Figure 2
Diagrammatic representation of the angles measured.
Figure 3
Figure 3
LODOX machine.
Figure 4
Figure 4
LODOX image.

References

    1. Jeffries LJ, Milanese SF, Grimmer-Somers KA. Epidemiology of adolescent spinal pain: a systematic review of the research literature. Spine. 2007;32:2630–2637.
    1. Grimmer K, Williams M. Gender-age environmental associates of adolescent low back pain. Applied Ergonomics. 2000;31:343–360. doi: 10.1016/S0003-6870(00)00002-8.
    1. Burton AK, Clarke RD, McClune TD, Tillotson KM. The natural history of low back pain in adolescents. Spine. 1999;21:2323–2328. doi: 10.1097/00007632-199610150-00004.
    1. Murphy S, Buckle P, Stubbs D. The use of the portable ergonomic observation method (PEO) to monitor the sitting posture of schoolchildren in the classroom. Applied Ergonomics. 2002;33:365–370. doi: 10.1016/S0003-6870(02)00003-0.
    1. Louw QA, Morris LD, Grimmer-Somers KA. The prevalence of low back pain in Africa: a systematic review. BMC Musculoskeletal Disorders. 2007;8:105. doi: 10.1186/1471-2474-8-105.
    1. Ritzwoller DP, Crounse L, Shetterly S, Rublee D. The association of comorbidities, utilization and costs for patients identified with low back pain. BMC Musculoskeletal Disorders. 2006;7:72. doi: 10.1186/1471-2474-7-72.
    1. Bakker EW, Verhagen AP, Lucas C, Koning HJ, Koes BW. Spinal mechanical load: a predictor of persistent low back pain? A prospective cohort study. Eur Spine J. 2007;16:933–41. doi: 10.1007/s00586-007-0347-5.
    1. Kratenova J, Zejglicová K, Malý m, Filipová V. Prevalence and risk factors of poor posture in school children in the Czech Republic. J Sch Health. 2007;77:131–7. doi: 10.1111/j.1746-1561.2007.00182.x.
    1. El-Metwally A, Salminen JJ, Auvinen A, Macfarlane G, Mikkelsson M. Risk factors for development of non-specific musculoskeletal pain in preteens and early adolescents: a prospective 1-year follow-up study. BMC Musculoskeletal Disorders. 2007;8:46. doi: 10.1186/1471-2474-8-46.
    1. National Institute for Occupational Safety and Health (NIOSH) Musculoskeletal disorders and work place factors . Cincinnati, OH: US Department of Health and Human Services. 1997. Retrieved March 27, 2006;
    1. Vieira ER, Kumar S. Working postures: A literature review. Journal of Occupational Rehabilitation. 2004;14:143–159. doi: 10.1023/B:JOOR.0000018330.46029.05.
    1. Saito S, Miyao M, Kondo T, Sakakibara H, Toyoshima H. Ergonomic evaluation of working postures of VDT operation using personal computer with flat panel display. Ind Health. 1997;35:264–70. doi: 10.2486/indhealth.35.264.
    1. Trevelyan FC, Legg SJ. Back pain in school children – where to from here? Applied Ergonomics. 2006;37:45–54. doi: 10.1016/j.apergo.2004.02.008.
    1. Ming Z, Närhi M, Siivola J. Neck and shoulder pain related to computer use. Pathophysiology. 2004;11:51–56. doi: 10.1016/j.pathophys.2004.03.001.
    1. Szeto GPY, Straker LM, O'Sullivan PB. A comparison of symptomatic and asymptomatic office workers performing monotonous keyboard work – 2: Neck and shoulder kinematics. Manual Therapy. 2005;10:281–291. doi: 10.1016/j.math.2005.01.005.
    1. Szeto GPY, Straker L, Raine S. A field comparison of neck and shoulder postures in symptomatic and asymptomatic office workers. Applied Ergonomics. 2002;33:75–84. doi: 10.1016/S0003-6870(01)00043-6.
    1. Pringle RK. Intra-instrument reliability of 4 goniometers. Journal of Chiropractic Medicine. 2003;3:91–95. doi: 10.1016/S0899-3467(07)60051-2.
    1. Youdas JW, Carey JR, Garrett TR. Reliability of measurements of cervical spine range of motion – comparison of three methods. Physical Therapy. 1991;71:98–106.
    1. Tousignant M, de Bellefeuille L, O'Donoughue S, Grahovac S. Criterion validity of the cervical range of motion (CROM) goniometer for cervical flexion and extension. Spine. 2000;25:324–330. doi: 10.1097/00007632-200002010-00011.
    1. Lee CN, Robbins DP, Roberts HJ, Feda JT, Bryan JM, Masullo L, Flynn TW. Reliability and validity of single inclinometer measurements for thoracic spine range of motion. Physiotherapy Canada. 2003;55:73–78. doi: 10.2310/6640.2003.37854.
    1. Malmström E, Karlberg M, Melander A, Magnusson M. Zebris versus Myrin: A comparative study between a three-dimensional ultrasound movement analysis and an inclinometer/compass method. Spine. 2003;28:E433–E440. doi: 10.1097/01.BRS.0000090840.45802.D4.
    1. Tousignant M, Boucher N, Bourbonnais J, Gravelle T, Quesnel M, Brosseau L. Intratester and intertester reliability of the Cybex electronic digital inclinometer (EDI-320) for measurement of active neck flexion and extension in healthy subjects. Manual Therapy. 2001;6:235–241. doi: 10.1054/math.2001.0419.
    1. Moffet JAK, Hughes I, Griffiths P. Measurement of cervical spine movements using a simple inclinometer. Physiotherapy. 1989;76:309–312.
    1. Harrison DE, Haas JW, Cailliet R, Harrison DD, Holland B, Janik TJ. Concurrent validity of the flexicurve instrument measurements: Sagittal skin contour of the cervical spine compared with lateral cervical radiographic measurements. Journal of Manipulative and Physiological Therapeutics. 2005;28:597–603. doi: 10.1016/j.jmpt.2005.08.012.
    1. Hinmann M. Interrater reliability of flexicurve postural measures among novice users. Journal of Back and Musculoskeletal Rehabilitation. 2004. pp. 33–36.
    1. Grimmer K, Dansie B, Milanese S, Pirunsan U, Trott P. Adolescent postural response to experimental backpack loads. BMC Musculoskeletal Disorders. 2002;3:10. doi: 10.1186/1471-2474-3-10.
    1. Dunk NM, Lalonde J, Callaghan JP. Implications for the use of postural analysis as a clinical diagnostic tool: reliability of quantifying upright standing postures from photographic images. J Manipulative Physiol Ther. 2005;28:386–92. doi: 10.1016/j.jmpt.2005.06.006.
    1. McEvoy MP, Grimmer K. Reliability of upright posture measurements in primary school children. BMC Musculoskeletal Disorders. 2005;6:35. doi: 10.1186/1471-2474-6-35.
    1. Harrison DE, Harrison DD, Troyanovich SJ. Reliability of spinal displacement analysis of plain Radiographs: a review of commonly accepted facts and fallacies with implications for chiropractic education and technique. J Manipulative Physiol Ther. 1998;21:252–66.
    1. Wagner M, Böwing B, deimling M, Rascher W, Rupprecht T. Low field thoracic MRI – a fast and radiation free routine imaging modality in children. Magnetic Resonance Imaging. 2001;19:975–83. doi: 10.1016/S0730-725X(01)00417-9.
    1. Beningfield S, Potgieter H, Nicol A, Van As S, Bowie G, Hering E, Latti E. Report on a new type of trauma full-body digital Radiograph machine. Emergency Radiology. 2003;10:23–29.
    1. Fenety PA, Putnam C, Walker JM. In-chair movement; validity, reliability and implications for measuring sitting discomfort. Applied Ergonomics. 2000;31:383–93. doi: 10.1016/S0003-6870(00)00003-X.
    1. Wong WY, Wong MS. Detecting spinal posture change in sitting positions with tri-axial accelerometers. Gait Posture. 2008;27:168–171. doi: 10.1016/j.gaitpost.2007.03.001.
    1. Smith L, Louw Q, Crous L, Grimmer K. Development and testing of a new measurement tool for assessing musculoskeletal dysfunction among school learners. 2007. (under review)
    1. Grimmer K, Nyland L, Milanese S. Repeated measures of recent headache, neck and upper back pain in Australian adolescents. Cephalagia. 2006;26:843–851. doi: 10.1111/j.1468-2982.2006.01120.x.
    1. Bullock MP, Foster NE, Wright CC. Shoulder impingement: The effect of sitting posture on shoulder pain and range of motion. Manual Therapy. 2005;10:28–37. doi: 10.1016/j.math.2004.07.002.
    1. Portney LG, Watkins MP. Foundations of clinical research: Applications to practice. NY Prentice-Hall: Upper Saddle River; 2000.
    1. Norkin CC, Levangie PK. Joint structure and function: A comprehensive analysis. Philadelphia PA: FA Davis;

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