Abstract

Aim:

To identify postural variations in the positioning of the head, cervical spine and shoulders of children in two phases - preschool and school.

Methods:

This was a longitudinal study, a convenience sample with 99 children of both genders, in preschool (5-6 years old) and school (8-11 years old) phases. The postural alignment of the head, cervical spine and shoulders was evaluated through computerized photogrammetry and analyzed by SAPo software.

Results:

Differences were found between preschool and school phases, but only the variables of shoulder angle (SA) and forward head distance (FHD) were significantly different (SA = 32.79 [30.49 - 35.09] and 35.84 [33.53 - 38.15] p = 0.026, respectively; FHD = 8.40 [8.07 - 8.73] and 11.23 [10.94-11.52] p <0.001, respectively). A positive correlation was obtained between forward head distance and body mass (rho= 0.597, p <0.001).

Conclusion:

There are changes in head and shoulder alignment between preschool and school phases, with protrusion of shoulders and forward head distance findings in children who have evolved their posture. Therefore, parents should be aware of children’s posture, and health and education professionals should be involved in screening and prevention programs.

Keywords:
child; growth and development; photogrammetry

Introduction

Posture can be defined as a set of positions of the different joints of the body in a certain period, the correct posture being considered one in which minimum stress is applied to the joints¹1 Magee DJ. Orthopedic physical assessment. Saunders, Elsevier Health Sciences, 2014.. The head and shoulders should follow a correct alignment where the acromion and the external auditory meatus are aligned along the same vertical line²2 Kendall FP, McCreary EK, Provance P. Muscle testing and function. Baltimore, 1993.. The cervical spine in the sagittal plane should be slightly curved forward and the distance between the head and the cervical spine should be evidenced³3 Santos A. Diagnostico clinico postural um guia pratico. Summus editorial, 2001..

Currently, postural change in children is one of the most common health problems of childhood⁴4 Wyszynska J, Podgórska-Bednarz J, Drzal-Grabiec J, Rachwal M, Baran J, Czenczek-Lewandowska E, et al. Analysis of relationship between the body mass composition and physical activity with body posture in children. BioMed Res Int. 2016;(2016).. Thus, a high percentage of cases of children with postural problems gives warning for the need of prevention programs, in view of their early onset⁴4 Wyszynska J, Podgórska-Bednarz J, Drzal-Grabiec J, Rachwal M, Baran J, Czenczek-Lewandowska E, et al. Analysis of relationship between the body mass composition and physical activity with body posture in children. BioMed Res Int. 2016;(2016).. The position of the head, cervical spine and shoulders of children has been the subject of several studies, due to the effects that the combination of daily factors of life can cause, for example: inadequate sitting posture for a long time, mainly during the use of electronics; being overweight; incorrect ways of carrying backpacks; school furniture with dimensions not suitable for body structure; sedentary lifestyle habits⁵5 Straker LM, O'sullivan PB, Smith A, Perry M. Computer use and habitual spinal posture in australian adolescents. Public Health Rep. 2007;122(5):634-643.^-8. Azabagic, Spahic, Pranjic, Mulic⁸8 Azabagic S, Spahic R, Pranjic N, Mulic M. Epidemiology of musculoskeletal disorders in primary school children in bosnia and herzegovina. Mater Sociomed. 2016;28(3):164-67. evaluated the posture and daily habits of 1315 schoolchildren, aged 8 to 12 years, and showed that school-aged children spent practically 95% of their time in the seated position in school and approximately 1.5 hours sitting at home in front of electronics. In addition, the study by Foehr showed that American children spend more than 60 minutes a day in front of the computer⁹9 Foehr UG, Rideout V, Roberts DF. Generation M: Media in the lives of 8-18 year-olds. . 2005.. In fact, all of these factors can lead to musculoskeletal disorders in children such as developing postural deformities and pain⁷7 Brzek A, Dworrak T, Strauss M, Sanchis-Gomar F, Sabbah I, Dworrak B, et al. The weight of pupils' schoolbags in early school age and its influence on body posture. BMC musculoskelet disord. 2017;18(1):117.^,8.

Most children can stay in the sitting posture with their torso, back and cervical spine flexed or rotated for longer periods and associated with use of heavy backpacks for longer time develops the increase of kyphosis angle in both girls and boys principally in the phase of growth and development (preschool and school)⁷7 Brzek A, Dworrak T, Strauss M, Sanchis-Gomar F, Sabbah I, Dworrak B, et al. The weight of pupils' schoolbags in early school age and its influence on body posture. BMC musculoskelet disord. 2017;18(1):117.. The association of children and adolescents with this lifestyle and changes in posture habits can present consequences in the present and in the future, since children and adolescents are in the growth and development phase. Therefore, the objective of this study was to characterize the posture of the head, cervical spine and shoulders in the sagittal plane, by means of photogrammetry. This study was conducted on children in two distinct periods, the preschool and school phases, and it sought to verify the postural variations that occurred. We also aimed to investigate differences between the sexes as well as excess weight in the evolution process of posture. The hypothesis was that the posture of the head, cervical spine and shoulders in preschool boys and girls (5-6 years old) is different than in the school phase (8-11 years old).

Methods

The present study examined postural evolution in a convenience sample taken from the study of Prado, Beresoski, Camargo, Fernandes, Siqueira, Fujisawa¹⁰10 Prado DBAL, Beresoski CM, Camargo MZ, Fernandes KBP, Siqueira CPCM, Fujisawa DS. Sinais precoces de escoliose em crianças pré-escolares. Fisioter Pesq. 2015;22(1):69-75.. However, in the second stage of the study (4 years after the initial evaluation), some children had moved from their school or city, which resulted in a reduction in the sample size to 99 children. All participants were evaluated from 2011 to 2016, initially at five to six years old (pre-school period) and after approximately three years they were reassessed, at that time in the age group of eight to eleven years old (school period). Children who were excluded from the study belonged to one or more of the following categories of students who: were unable to remain in orthostatic position for the examination; had no understanding or no cooperation in the evaluation; presented chronic or acute disease; had undergone recent surgeries that could interfere with posture; presented physical and/or sensorial impairment; presented neurological, musculoskeletal or cardiorespiratory dysfunction and those whose parents did not approve of participation in the study.

The study was developed in 13 municipal schools in Londrina- PR in a random selection of schools (performed by the Secretary of Education based on the availability of the school). However, representation of all areas of coverage of the municipality was sought.

This was a longitudinal study, with approval by the Ethics Committee of the Universidade Estadual de Londrina (Etic No 1.170.330), Londrina, PR (protocol number CAAE 46540815.1.0000.5231). All parents and/or guardians of the children who participated in the study signed a consent form, according to the recommendation of NHC Resolution 466/12¹¹11 Resolução N. 466 do conselho nacional de saúde, de 12 de dezembro de 2012 (BR). Aprova as diretrizes e normas regulamentadoras de pesquisas envolvendo seres humanos. Diário Oficial da União. 2013;13..

Evaluation procedures

Participants were submitted to the same evaluation at both times: the first one between 2011 and 2013 (preschool), and the second one (school) between 2015 and 2016. All evaluations were performed by physiotherapists properly trained and linked to the research project (the same physiotherapist performed all evaluations). The evaluation was composed of verification of anthropometric measurements, followed by postural evaluation through photogrammetry.

Measurement Protocols

The children were weighed and measured for height using a digital scale (brand Marte, model LC200, serial number 314136, year 2010, with maximal capacity of 200 kg and minimum of 1000g) and a tape measure fixed on the wall, respectively.

To determine the child´s nutritional status, body mass index (BMI) was calculated using AnthroPlus software, available free on the WHO website. The software provides references for overweight and obesity by weight, height and BMI. Z Score values less than -2 indicate low weight; between -2 and +1 eutrophy; between +1 and +2 overweight; and over +2 obesity¹²12 de Onis M, Onyango AW, Borghi E, Siyam A, Nishida C, Siekmann J. Development of a WHO growth reference for school-aged children and adolescents. Bulletin of the World Health Organization. 2007; 85:660-7..

The use of photogrammetry as a tool for postural evaluation has been recommended since it is a safe method and it allows large scale studies in the child population¹³13 Araújo F, Severo M, Alegrete N, Howe L, Lucas R. Defining patterns of sagittal standing posture in school-aged girls and boys. Phys Ther. 2017;97(2):258-267.. Photogrammetry has been considered a valid method¹⁴14 van Niekerk S, Louw Q, Vaughan C, Grimmer-Somers K, Schreve K. Photographic measurement of upper-body sitting posture of high school students: A reliability and validity study. BMC musculoskelet disord. 2008;9(1):113.^,15 with acceptable reproducibility¹⁶16 Ferreira EAG, Duarte M, Maldonado EP, Burke TN, Marques AP. Postural assessment software (PAS/SAPO): Validation and reliabiliy. Clinics. 2010;65(7):675-681.^-18.

The children were positioned in comfortable orthostatism in front of a non-reflective black background, according to requirements of the software used for photo analysis. Images were captured from the right and left side views, with spherical styrofoam markers with a diameter of 1.5 cm and flexible white plastic rods, stuck by double-sided tape, at anatomic points for posterior analysis of articular angles. The markers for analysis of the angles were fixed in the anatomical points: C7, tragus and acromion.

A digital camera (Samsung, 10.2 mega pixels) was positioned parallel to the floor on an aluminum tripod (Lightweight Tripod,marca VF - WT3510A), at a height of 108 centimeters and 2.50 m away from the children, in a set place for all participants. The rooms for evaluation provided participant privacy. Data were evaluated through analysis of scanned images using the software SAPo (Postural Analysis Software), which is free and has been developed for image processing and analysis¹⁶16 Ferreira EAG, Duarte M, Maldonado EP, Burke TN, Marques AP. Postural assessment software (PAS/SAPO): Validation and reliabiliy. Clinics. 2010;65(7):675-681..

Analyses were made of angular and linear measurements in the sagittal plane (Figure 1) and analyzed by a single trained evaluator. Studies have shown good inter and intra observer reliability for evaluation through photogrammetry¹⁶16 Ferreira EAG, Duarte M, Maldonado EP, Burke TN, Marques AP. Postural assessment software (PAS/SAPO): Validation and reliabiliy. Clinics. 2010;65(7):675-681.^,19,20. The variables used in the study were:

_ Sagittal Head Angle (SHA): the axis at the tragus and two lines, one parallel to the floor and the other joining the tragus to the canthus of the eye. The greater the angle, the greater the cervical extension²¹21 Ruivo RM, Pezarat-Correia P, Carita AI. Intrarater and interrater reliability of photographic measurement of upper-body standing posture of adolescents. J Manipulative Physiol Ther. 2015;38(1):74-80.;

_ Cervical Angle (CA): the axis in the spinous process of C7, which joins the line between the tragus and the spinous process of C7 with another parallel to the floor. The lower the CA value, the more forward the head is positioned⁶6 Kim M, Yi C, Kwon O, Cho S, Yoo W. Changes in neck muscle electromyography and forward head posture of children when carrying schoolbags. Ergonomics. 2008;51(6):890-901.^,21;

_ Shoulder Angle (SA): formed by the intersection of the spinous process of C7 and the acromion with a parallel line on the floor; the position of the shoulders in protraction/retraction was determined²¹21 Ruivo RM, Pezarat-Correia P, Carita AI. Intrarater and interrater reliability of photographic measurement of upper-body standing posture of adolescents. J Manipulative Physiol Ther. 2015;38(1):74-80.;

_ Forward head distance (FHD): calculated between the tragus and the spinous process of C7. A higher value indicates a forward head position⁶6 Kim M, Yi C, Kwon O, Cho S, Yoo W. Changes in neck muscle electromyography and forward head posture of children when carrying schoolbags. Ergonomics. 2008;51(6):890-901.^,13,22.

Statistical Analysis

All statistical analyses were performed using SPSS statistical software (version 20.0 for Windows) with an alpha level of 0.05. All variables were normally distributed based on the Shapiro-Wilk test. The paired T Student test was used for group comparison (assessment and reassessment). A mixed model 2x2 ANOVA was used. The main effects studied were participants (girls vs. boys) and group (assessment vs reassessment) and correlations between variables were verified using the Spearman correlation.

Results

A total of 99 children were evaluated and 51 were girls (51.5%). In relation to anthropometric data, there were statistically significant differences between assessment (preschool) and reassessment (school) for all variables (p <0.001), except for Z score results (p>0.05). However, no significant difference between girls’ and boys’ body mass was found. Sample characteristics are reported in Table 1.

The postural variables evaluated by photogrammetry are reported in Table 2, which were analyzed using four angles and the linear distance in the sagittal plane. The variables analyzed between assessment (preschool) and reassessment (school) showed significant differences for SA and FHD (p<0.03), demonstrating that in reassessment children have an average SA and a higher FHD than in the assessment.

Table 3 shows the results of postural variables for girls and boys at both times (assessment and reassessment). At reassessment, girls showed significant differences only in the FHD variable (p <0.001); while the boys presented significant differences for SHA, SA and FHD variables (p <0.04). For the CA variable, no significant differences were found for both groups (girls and boys). For multiple comparisons, no significant differences were found between the variables for girls and boys (F= .053-2.54, p>0.05).

Spearman correlation demonstrated that the forward head distance variable had a positive correlation with children´s body mass in the reassessment (rho= 0.595; p <0.001); for all other correlations no important relation was found among variables (rho= 0.076 - 0.184; p>0.05).

Discussion

In the present study, certain variables (angular and linear) were selected to determine the head, cervical spine and shoulder position in the sagittal plane and thus to characterize children´s posture in the preschool and school periods. Significant differences were observed for head, cervical and shoulder alignment between these two periods of assessment, demonstrating postural changes with the growth and development of the children (confirming our hypothesis).

Head positioning was verified by several variables, but only for FHD, in the proposed initial alignment, was a difference observed between preschool and school periods. An increased forward head distance was observed at school age, which indicates a forward positioning (forward head). With forward head, it is possible to observe disuse of the deep cervical flexor muscle and dominance of the superficial cervical flexor, such as the sternocleidomastoid muscle (SCM), tonic contraction of the SCM, sustained cervical flexion movements and shortening of this muscle²³23 Bokaee F, Rezasoltani A, Manshadi FD, Naimi SS, Baghban AA, Azimi H. Comparison of cervical muscle thickness between asymptomatic women with and without forward head posture. Braz J Phys Ther. 2017;21(3):206-211.. The difference found in head positioning between preschool and school age can be explained as normal postural alteration from musculoskeletal maturation but can be aggravated by the weight of schoolchildren’s backpacks⁶6 Kim M, Yi C, Kwon O, Cho S, Yoo W. Changes in neck muscle electromyography and forward head posture of children when carrying schoolbags. Ergonomics. 2008;51(6):890-901. and daily postural habits such as long periods of sitting in an inappropriate position during classes and activities at home, which produce inappropriate head, shoulder and spinal posture²⁴24 Park H, Kim Y, Seok S, Lee S. The effect of complex training on the children with all of the deformities including forward head, rounded shoulder posture, and lumbar lordosis. J Exerc Rehabil. 2014;10(3):172-175.^,25.

Analysis of the shoulder angle variable showed a difference between the two periods (preschool and school), where shoulder protrusion was observed in the preschool children. Ruivo, Pezarat-Correia, Carita²¹ considered in their study that those who had a shoulder angle less than 52º had shoulder protrusion. Therefore, the present study provides evidence of forward shoulder for these children, independent of age, but with a worse position in the preschool period (approximately 33º). The higher incidence in children with protracted shoulders is normal during the growth and development period, which should decrease after 10 years old²⁶26 Santos CIS, Cunha ABN, Braga VP, Saad IAB, Ribeiro MAGO, Conte PBM, et al. Ocorrência de desvios posturais em escolares do ensino público fundamental de Jaguariúna. Rev Paul Pediatr. 2009;21(1):74-80.. Lafond, Descarreaux, Normand, Harrison²⁷27 Lafond D, Descarreaux M, Normand MC, Harrison DE. Postural development in school children: A cross-sectional study. Chiropr Osteopat. 2007;15(1):1. evaluated children 4-12 years old and observed a tendency towards forward head and shoulder displacement according to the child´s development. These postural modifications are the result of normal musculoskeletal maturation between childhood and adolescence that could be an adaptation process for adequate sagittal balance, but inappropriate postural habits may favor or even worsen this posture²⁶26 Santos CIS, Cunha ABN, Braga VP, Saad IAB, Ribeiro MAGO, Conte PBM, et al. Ocorrência de desvios posturais em escolares do ensino público fundamental de Jaguariúna. Rev Paul Pediatr. 2009;21(1):74-80..

The comparison of boys’ and girls’ posture at assessment and reassessment showed some differences in relation to head, cervical and shoulder positioning only within the group. At reassessment, girls showed differences only in the FHD variable, whileboys presented differences for SHA, SA and FHD variables. On the other hand, in this study, the results for comparison among girls and boys were similar for all variables. Shaheen & Basuodan²⁸28 Shaheen AA, Basuodan RM. Quantitative assessment of head posture of young adults based on lateral view photographs. J Phys Ther Sci. 2012;24(5):391-394. compared head position in children of both sexes between 7 and 9 years old and they observed a significant difference in posture, with girls presenting greater forward head than boys. However, another study corroborate with our finding that there were no differences between the sexes regarding some postural angles (ie trunk, cervical spinal, head) among children from 5 to 12 years old²⁹29 McEvoy MP, Grimmer K. Reliability of upright posture measurements in primary school children. BMC musculoskelet disord. 2005;6(1):35..

The FHD variable showed a positive correlation in reassessment in relation to children´s body mass. Therefore, the greater the child´s body mass, the greater the value of the forward head distance variable, indicating forward head and a worse postural pattern. Silva, Rodacki, Brandalize, Lopes, Bento, Leite³⁰30 Silva LRD, Rodacki ALF, Brandalize M, Lopes MFA, Bento PCB, Leite N. Postural changes in obese and non-obese children and adolescents. Rev Bras Cineantropom Desempenho Hum. 2011;13(6):448-454. in their study evaluated posture using photogrammetry in 33 children from 9 -17 years old, obese and non-obese, and they observed that obese children presented a higher frequency of forward head. Being overweight, more than metabolic changes, causes changes in body posture and postural control, because the presence of fat concentration in the abdominal area promotes a forward movement of the center of gravity, resulting in many postural changes, such as an increase of cervical lordosis and forward head as a way to recover body balance³¹31 Camargo CS, Pereira K. Progression of anthropometric variables, posture and balance of obese and overweight children. ConScientiae Saúde. 2012;11(2):256.^,32.

Postural changes such as protracted shoulder and forward head are becoming common among children and adolescents, which may persist and cause pain in adulthood²¹21 Ruivo RM, Pezarat-Correia P, Carita AI. Intrarater and interrater reliability of photographic measurement of upper-body standing posture of adolescents. J Manipulative Physiol Ther. 2015;38(1):74-80.. Postural deviations presented in this age group may have been a consequence of natural physiological changes of growth and development²⁷27 Lafond D, Descarreaux M, Normand MC, Harrison DE. Postural development in school children: A cross-sectional study. Chiropr Osteopat. 2007;15(1):1.. Postural changes from 7 to 12 years old occur in order to find a balance compatible with new body proportions acquired by growth. Ruivo, Pezarat-Correia, Carita²¹21 Ruivo RM, Pezarat-Correia P, Carita AI. Intrarater and interrater reliability of photographic measurement of upper-body standing posture of adolescents. J Manipulative Physiol Ther. 2015;38(1):74-80. discuss in their study that possible causes found for postural changes are incorrect use of backpacks, school furniture, biopsychosocial factors such as depression and stress, a higher amount of time in a seated posture and an incorrect body positioning during school time or at home. Finally, daily health habits, both at home or at school, could support the appearance or worsening of postural asymmetry in the sagittal plane.

The number of children who participated, which was based on a convenience sample and not on a representative population sample, could be considered a limitation of the study. The sitting time, weight of schoolchildren’s backpacks and physical activity were not evaluated. The lack of standardization of some measurements of photogrammetry can also be stated as one of the study’s limitations, since there are no studies with standardized measures to help compare postural changes and assist discussions on findings.

Practical implications of this study suggest alerting parents and teachers to pay attention to the posture of children not only in the school phase, but also in the preschool stage. Orienting children’s lifestyle and posture habits is important so that negative effects on posture do not occur during the growth and development period and thus carry over into adulthood. Therefore, parents should be aware of children’s posture, and health and education professionals should be involved in screening and prevention programs in order to develop healthy habits, especially those related to body positioning.

Conclusion

Our results showed that the head, cervical spine and shoulder posture of children in two periods, assessment (preschool) and reassessment (school), suffered postural changes, mostly forward head and protracted shoulder.

Early follow-up of body posture in childhood should be encouraged and guided, seeking to minimize further problems. In fact, it is important to emphasize that care and guidance should be practiced early in children, suggesting that health policies could be implemented in this population.

References

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History