- Email: [email protected]
Intrarater and Interrater Reliability of Photographic Measurement of Upper-Body Standing Posture of Adolescents
INTRARATER AND INTERRATER RELIABILITY OF PHOTOGRAPHIC MEASUREMENT OF UPPER-BODY STANDING POSTURE OF ADOLESCENTS Rodrigo Miguel Ruivo, MsC, a Pedro Pezarat-Correia, PhD, b and Ana Isabel Carita, PhD c
ABSTRACT Objective: The purposes of this study were to determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and analyze differences in postural angles between sexes. Methods: This cross-sectional study was conducted in 2 secondary schools in Portugal where 275 adolescent students (146 females and 129 males) aged 15 to 17 years were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and the Postural Assessment Software. Results: For interrater reliability, all of the intraclass correlation coefficient (ICC) values for the 3 angles were higher than 0.85. For intrarater reliability, the ICC values for the sagittal head angle, shoulder angle, and cervical angle were 0.83, 0.78, and 0.66, respectively. Mean values of sagittal head, cervical, and shoulder angles were 17.2° ± 5.7°, 47.4° ± 5.2°, and 51.4° ± 8.5°, respectively. Anterior head carriage was demonstrated by 68% of the adolescents, whereas 58% had protraction of the shoulder(s). Males had significantly higher mean cervical and sagittal head angles. Conclusions: Forward head posture and protracted shoulders were common postural disorders in adolescents 15 to 17 years old, with females revealing a lower mean cervical angle. The intrarater and interrater evaluation of standing sagittal posture of the cervical spine and shoulders by photogrammetry was reliable. (J Manipulative Physiol Ther 2015;38:74-80) Key Indexing Terms: Adolescent; Head; Photogrammetry; Posture; Shoulder
osture has been defined as the alignment of the body segments at a particular time 1 and is an important health indicator. 2 it is believed that an efficient, erect human posture should allow for the maintenance of balance using the least musculoskeletal effort without a feeling of discomfort. 3 Epidemiological studies have shown a high prevalence of spinal postural deviations in children and adolescents. 4,5 Other outcome studies have shown that musculoskeletal pain has become a major symptomatic complaint among
P a
Assistant, Faculdade de Motricidade Humana, Lisboa, Portugal. Professor, Faculdade de Motricidade Humana, Universidade de Lisboa, Laboratório de Comportamento Motor, Lisboa, Portugal. c Professor, Faculdade de Motricidade Humana, Universidade de Lisboa, Secção Autónoma de Métodos Matemáticos, Lisboa, Portugal. Submit requests for reprints to: R.M. Ruivo, MsC, Assistant, Avenida Fernando Pessoa, lote 3.20.01, Bloco B, 4 A, 1990-102 Lisbon, Portugal. (e-mail: [email protected]). Paper submitted December 29, 2013; in revised form August 17, 2014; accepted August 25, 2014. 0161-4754 Copyright © 2015 by National University of Health Sciences. http://dx.doi.org/10.1016/j.jmpt.2014.10.009 b
children and adolescents. The shoulder and neck regions are cited in many references as the areas of greatest discomfort in adults and adolescents. 6–8 For example, Perry et al 6 and Diepenmaat et al 9 reported that the monthly prevalence rates for adolescent neck and shoulder pain are increasing and range between 11.5% and 29%. Postural assessment through photography may be a simple method that allows the acquisition of quantitative values to define the alignment of body segments. Recent technological improvements have paved the way for the development of reliable and applicable methods to assist in adolescent postural assessment, such as computer-assisted systems for the analysis of posture photographs (photogrammetry). 2,10 This method has become widely used in the quantitative assessment of postural alignment, with the potential to quantify linear and angular measurements and with the advantage of allowing a record of subtle postural changes and the interrelation between different parts of the human body, 11 which are difficult to measure and register by other means. Specific software has been developed to assist with posture assessment from digitalized pictures, such as the Postural Assessment Software (PAS/SAPO) 10, 12.
Journal of Manipulative and Physiological Therapeutics Volume 38, Number 1
With a quantitative postural assessment method based on the measurement of different postural angles, it may be possible to identify postural problems such as forward head posture and protracted shoulder. Forward head posture includes cervical spine hyperextension and is associated with the shortening of the upper trapezius, the posterior cervical extensor muscles (suboccipital, semispinalis, and splenni), the sternocleidomastoid muscle, and the levator scapulae musculature. 13 This postural deviation can be studied based on the cervical angle, 4,14 which represents the angle formed at the intersection of a horizontal line through the spinous process of C7 and a line to the tragus of the ear, with smaller angles indicating a more forward head posture. Very often, 50° is chosen as a reference angle 14; and an individual is considered to have forward head posture if the angle is lower than that value. A protracted shoulder is a forward displacement of the acromion with reference to the seventh cervical spinous process and can be measured by the shoulder angle. It represents the intersection of the line between the midpoint of the humerus (or acromion process) and spinous process of C7 and the horizontal line through the midpoint of the humerus. Taking into account the importance of measuring postural deviations, the purposes of the present study were 3-fold: (1) determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, (2) quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and (3) analyze differences in postural angles between sexes.
METHODS Ethics The study was approved by the Research Ethics Committee of the Faculty of Human Kinetics of the Technical University of Lisbon. The participation of all students was voluntary, and written informed consent was obtained from all participants and their parents or legal guardians.
Setting This cross-sectional study was conducted in 2 public secondary schools, Lumiar Secondary School and Padre Antonio Vieira Secondary School, located in the city of Lisbon, Portugal. The choice of these schools was based on geographical issues and focused on the center of Lisbon.
Participants Male and female adolescent students between the ages of 15 and 17 years were eligible to participate. Participants were excluded if they had visual deficits, had diagnosed balance disorders, or were nonambulatory. Additional
Ruivo et al Standing Posture of Adolescents
Fig 1. Sagittal head angle, cervical angle, and shoulder angle. exclusion criteria were the presence of musculoskeletal pathologies, such as a history of shoulder surgery, current shoulder pain limiting activities, cervical or thoracic fracture, displayed functional or structural scoliosis, or excessive thoracic kyphosis. Given these criteria, a total of 275 adolescent students (146 females and 129 males) aged 15, 16, or 17 years old (15.76 ± 1.08 years) from 17 different classes (9 from the 10th grade, 7 from the 11th grade, and 1 from the 12th grade) were evaluated and included in the study.
Procedures Standing cervical and shoulder posture was measured with photogrammetry and PAS. Three angles of measurement were used: sagittal head angle, cervical angle, and shoulder angle. We chose these angles because they had been used in previous studies and were found to be reliable, 4 enabling the comparison of results. The angles (Fig 1) in the sagittal view were obtained as follows: Sagittal Head Angle. It is the angle formed at the intersection of a horizontal line through the tragus of the ear and a line joining the tragus of the ear and the external canthus of the eye. Cervical Angle. The cervical angle is used to assess the forward position. 4,14 It is the angle formed at the intersection of a horizontal line through the spinous process of C7 and a line to the tragus of the ear. In this study, if the angle was less than 50°, the participant was considered to have forward head posture. The selection of 50° as a reference angle was guided by the studies of Diab and Moustafa 14 and Yip et al, 15 with the latter reporting 55.02 ± 2.86 as a reference range. As is well known, participants
75
76
Ruivo et al Standing Posture of Adolescents
with forward head posture have a significantly smaller cervical angle when compared with healthy participants. 16 Shoulder Angle. It is the angle formed at the intersection of the line between the midpoint of the humerus and spinous process of C7 and the horizontal line through the midpoint of the humerus. Based on the premise that participants with protracted shoulder have a significantly smaller shoulder angle when compared with healthy participants, 17,18 considering a study by Brink et al 19 with adolescents 15 to 17 years old reporting a mean shoulder angle value of 51.35° ± 17.2°, a study by Thigpen et al 20 with 310 participants evaluated in a standing position that reported 52.6 ± 15.3 as a reference range, and a study by Raine and Twomey 18 with 160 participants evaluated in a standing position that reported 54.3° ± 11.5° as a reference range, we considered 52° as the reference angle. We considered an individual to have protracted shoulder (PS) if the angle was less than 52°. In the article of Thigpen et al (2010), the shoulder angle mentioned above was measured using a vertical line as a reference. However, to normalize the reading of the database, the horizontal line was considered as a reference. All measurements were performed by the same researcher who was experienced in the assessment of postural alignment. The photographing took place in the gymnasium of the 2 secondary schools with the areas arranged identically. Efforts were made to control the temperature, noise, and distractions. Landmarks were placed on the floor to ensure the same positioning of all participants in front of the camera, and the participant was aligned perpendicular to the camera. A landmark was placed in front of a white wall to ensure contrast of the participants against the background. One Canon Power Shot A4000 IS (Canon, Suzhou, China) was supported on a Manfrotto tripod, model 055 CLB (Tokyo, Japan), 3 m away from the line marking the position of the participant. The height of the tripod was adjusted so that the middle of the objective lens was 130 cm above the ground. A calibration board was placed on the white wall in the field of view and aligned with the participant to allow referencing of horizontal and vertical axes from the photographs. The calibration board also displayed each participant's identification number. For positioning, the adolescent was instructed to stand comfortably in a normal standing position and to look straight ahead. Marks on the floor ensured that all participants were placed in the same place. Before photographing, the researcher put reflective markers on the following anatomical points on the right side of the participant’s body: tragus of the ear, lateral canthus of the eye, the spinous process of C7, and midpoint of the humerus. With these markers, we were able to calculate the sagittal head angle, cervical angle, and shoulder angle. To enable precise positioning of the markers, we instructed the participants to wear tight shorts and sleeveless T-shirts, with an elastic for the hair when needed. The procedure was performed by the same researcher.
Journal of Manipulative and Physiological Therapeutics January 2015
To capture the participant’s natural head-on-trunk and shoulder alignment, each person was asked to look straight ahead and to march on the spot 5 times before each picture was taken. 21 Each picture was taken within 5 seconds of the marching sequence in a lateral view, with the right side of the participant photographed for the right-hand dominant individuals and the left side for the left-hand dominants. The dominant arm was defined as the one most used in daily activities. The investigator checked for the sagittal position of each participant to correct for segmental rotation before taking the photograph. The photographic analysis was subsequently performed using software for postural analysis (PAS), which determined the coordinates of the anatomical points on the photographs. The zoom was standardized at 200%, and the angles were measured in degrees. One researcher undertook all scanning and digitizing to eliminate interexaminer error. The data were submitted for descriptive statistical analysis, and quantitative values for head and upper member angles were obtained.
Reliability Study A separate preparatory study to confirm the inter- and intrarater reliability of computerized photogrammetry using the PAS was performed. The study sample consisted of 17 participants from a 10th-grade class. Three physical therapists (all men from 26 to 32 years old) who were not regular users of the PAS/SAPO but had used the software before were invited to participate as raters. Each student was photographed in precise conditions, and pictures were taken of the participants in random order. Using the PAS/ SAPO, raters performed the measurements. These procedures were repeated 1 week later, and the results were compared to assess the intrarater reliability.
Statistical Analysis All statistical analyses were performed using specific software (SPSS version 20, Chicago, IL), and the statistical significance level was defined as P b .05. Reliability was determined from the intraclass correlation coefficients (ICCs) by means of the 2-way model. The scale from Bland and Altman 22 was used in the classification of the reliability values. Intraclass correlation coefficient values less than or equal to 0.20 were considered poor, 0.21 to 0.40 was considered fair, 0.41 to 0.60 was considered moderate, 0.61 to 0.80 was considered good, and 0.81 to 1 was considered very good. Standard error of measurement (SEM) was used to examine the precision of the measurement and was calculated according to SEM = SD√1 − ICC. In the experimental study, the data were analyzed using descriptive statistics such as the mean, standard deviation, and percentage. The Shapiro-Wilk test was used to assess normality. To analyze differences between sexes in the 3 postural angles, an independent-samples t test was applied.
Journal of Manipulative and Physiological Therapeutics Volume 38, Number 1
Ruivo et al Standing Posture of Adolescents
Table 1. Intrarater and Interrater Reliability Findings: ICC and SEM Values for All Angles Intrarater Reliability Measurement
ICC (95% CI)
Measurement
Adolescents (Mean ± SD) N =275 (146 Female and 129 Male)
Age (y) Sagittal head tilt angle (°) Cervical angle (°) Shoulder angle (°)
15.76 ± 1.08 17.15 ± 5.74 47.39 ± 5.17 51.44 ± 8.55
Interrater Reliability
SEM ICC (95% CI)
Sagittal head angle 0.83 (0.60-0.94) 2.72 Cervical angle 0.66 (0.26-0.87) 3.54 Shoulder angle 0.78 (0.49-0.92) 4.03
Table 2. Demographic Characteristics of Participants and Descriptive Values for the Postural Angles (N = 275)
SEM
0.88 (0.75-0.95) 2.35 0.87 (0.74-0.95) 1.85 0.96 (0.92-0.99) 1.64
CI, confidence interval; ICC, intraclass correlation coefficient; SEM, standard error of measurement.
Relationships between the 3 postural angles were examined by calculating the Pearson r correlation coefficients (rs).
RESULTS Reliability Study The reliability of the photographic measurements is shown in Table 1. A total of 17 participants (14 females and 3 males) aged 15 to 17 years were recruited for the reliability study. The ICC values for the sagittal head angle (0.83) revealed very good reliability, whereas the values for the shoulder angle and for the cervical angle reported good reliability, with 0.78 and 0.66, respectively. All of the ICC values for the 3 angles reported very good interrater reliability, with the SEMs of the photographic measurement ranging between 1.64 and 2.35.
Experimental Study Sample Description. The demographic characteristics of the participants and descriptive values for the 3 postural angles are described in Table 2. With the aid of the photogrammetry and taking into consideration the reference values outlined previously, of the 275 students studied, 188 were found to have forward head (FH) with a cervical angle lower than 50°, whereas 131 of them had a shoulder angle less than 52°, revealing a PS. Only 47 students (17%) had no forward head posture or protracted shoulder, and 131 students (47, 6%) had both FH and PS. All of these values are shown in Figure 2. Differences Between Sexes on Postural Angle. The examination of the head and shoulder posture measurements to identify sex differences between males and females using an independent-samples t test is reported in Table 3. Significant differences were observed between males and females with respect to the sagittal head angle and the cervical angle, with males having a higher mean value (18.4 ± 6.03 vs 16.15 ± 5.31 and 48.43 ± 4.91 vs 46.55 ± 5.24, respectively).
DISCUSSION Reliability Study The present study demonstrated very good reliability for the interrater measurements in the same image for all of the variables studied, with ICC values greater than 0.90 and
Fig 2. Percentage of students demonstrating forward head and/or protracted shoulders. FH, forward head; FHP, forward head posture; PS, protracted shoulder. low values of SEM (1.64-2.35). These results are in line with the values found by Falla et al. 16 Regarding the intrarater reliability, for the sagittal head angle and shoulder angle, the ICC values revealed very good and good reliability; and the cervical angle demonstrated good reliability in the normal standing posture with the second highest SEM value. With these data, we can suggest that the adolescents’ upper quadrant standing posture (quantified by 3 segmental angles) did not change significantly with repeated testing. The same finding was reported by McEvoy and Grimmer al 2 with children (5-12 years) and for all body angles (quantified by 5 whole-body or segmental angles).
Postural Study Descriptive Statistics. There is sparse literature providing evidence of cervical and shoulder postural alignment among 15- to 17-year-old adolescents. In addition to facilitating the report of standing postural alignment for a specific and important age group, this study has the advantage of evaluating a far larger sample than others 4,17 and analyzing sex differences. In this study, a large percentage of the participants displayed some degree of postural abnormality in the cervical and/or shoulder region: 68% and 58% of the students had FH and PS, respectively, whereas 47.6% of the total sample had both misalignments. The incorrect use of heavy backpacks, 23 the lack of ergonomy of the school furniture, 24 psychosocial factors such as depression or stress, 25 and the practice of spending many hours seated with incorrect posture in school and in
77
78
Ruivo et al Standing Posture of Adolescents
Journal of Manipulative and Physiological Therapeutics January 2015
Table 3. Effect of Sex on the 3 Postural Angles Measurement Sagittal head tilt angle (°) ⁎ Cervical angle (°) ⁎ Shoulder angle (°)
Females (n=153)
Males (n=122)
Independent-Samples t Test
Mean
SD
Mean
SD
t
P
16.15 46.55 51.09
5.31 5.24 8.28
18.48 48.44 51.9
6.03 4.91 8.92
− 3.3 − 3.05 − 0.77
.001 .002 .445
⁎ Statistically significant difference (P b .05).
front of computers and televisions 19 may be responsible for this finding. Specifying the angles studied, in this study, we chose the sagittal head, cervical, and shoulder angles because they are the most frequently cited in the literature, enabling the comparison of results. These analyses help us to characterize the posture of a patient regarding the head and shoulder position, and they are reliable. 26 For example, the cervical angle is highly reliable to assess the forward head position. 4 The sagittal head angle measures the alignment of the upper cervical spine. 27 The mean head tilt angle registered (17.15° [5.7]) is similar to a study by Chansirinukor et al 17 with adolescents (13-16 years old) in standing position, which reported a mean sagittal head angle of 16.3°. In other studies, Brink et al 19 studied 107 adolescents (15-17 years old) and reported a mean value of 13.8°, whereas Van Niekerk et al 4 studied a sample of 40 adolescents (16-17 years old) and described a mean value of 20.1°. In both studies, adolescents were evaluated in a seated position. De Wall et al 28 recommended that a suitable head tilt angle would be 15° above the horizontal. For the cervical angle, a smaller angle indicates a more FHP. 14 The mean CV angle obtained, 47.4° (5.17), is similar to the one reported by Van Niekerk et al, 4 47.6 (9.75), who evaluated 40 16- to 17-year-old adolescents. In another study of 94 students aged 15 to 17 years old, Brink et al 19 found a smaller cervical angle, 39.27 (7.9), which they considered the cause of upper quadrant pain. The shoulder angle is an angle that provides a measurement of the shoulder position. The mean shoulder angle obtained, 51.44° (8.56), is similar to the one found in the study of Brink et al 19 (51.35° [17.2]) and is slightly higher than the one found in Van Niekerk et al 4 (49.79° [25.7]). Both studies evaluated adolescents. A smaller angle indicates a protracted shoulder, which is frequently associated with a protracted, anterior tilted, and internally rotated scapula and with a tightness of the pectoralis minor muscle. 29 These shoulder alterations, which are also related to a decreased serratus anterior and lower trapezius activity, are associated with many clinical syndromes involving the shoulder 30,31 and with a reduced subacromial space. Postural deviations such as protracted shoulder and forward head posture are becoming common in adolescents 5 and can lead to upper quadrant musculoskeletal pain that can persist into adulthood. 19,32 As noted by Croft et al, 33 prior neck/shoulder pain is a strong risk factor for future neck/
shoulder pain in adults, with the consequent high economic cost of treating these symptoms. 25 Based on these premises, it becomes clear that something must be done to counteract this situation. Postural training and rehabilitation with the aim of preventing and managing upper quadrant musculoskeletal pain should be implemented at early ages, and schools and physical education classes may play an important role in this issue.
Differences Between Sexes on Postural Angles. After analyzing sex differences, females had a lower resting cervical angle than males (46.55° vs 48.44°). This finding is in accordance with Grimmer et al, 34 whose study of standing cervical habitual posture in adolescents found that females had 2° to 3° more neck flexion than males. 35 Briggs et al 35 proposed that this observation may be partly attributable to psychosocial issues associated with the development of secondary sex characteristics in females preceding those of males. In adults’ resting head-on-neck posture, significant sex differences in cervical angle have been observed, including a more forward head posture in women. 36 In contrast to the current study, 2 small-sample studies have reported no sex differences for cervical habitual posture in adolescents and preadolescents. 2,4 More research is required to clarify the role of sex in cervical posture. Correlating the cervical angle obtained in this study with pain and based on the premise that participants with neck pain have a significantly smaller cervical angle compared with healthy participants, 37 it can be hypothesized that young females would have more cervical pain. This hypothesis is in accordance with many other studies that have reported more neck pain in young females than in young males. 9,38 Regarding the shoulder angle, comparative studies of young males and females are much rarer. Similar to this study, with an adult sample, Raine and Twomey 18 found similar shoulder positions with respect to the seventh cervical in the sagittal plane for men and women. Regarding sex differences, it would be advisable and interesting in a future study to establish a relationship between head and shoulder postural deviations and the severity and frequency of pain in the upper quadrant region. Further studies should also address the evaluation of the effects of a training program applied in physical education classes in school on sagittal cervical shoulder posture in adolescents.
Journal of Manipulative and Physiological Therapeutics Volume 38, Number 1
Ruivo et al Standing Posture of Adolescents
LIMITATIONS Practical Applications One of the limitations of this study is that it describes only the alignment of the spine and the shoulder girdle at rest. Therefore, the findings cannot be generalized to alignment during functional tasks, especially when the upper limb is moving or loaded. This is also the case when activities are prolonged over time. Although this study aimed to minimize errors and bias in all procedures and setups, to obtain even better precision, future studies should apply a questionnaire on lifestyle habits at home and at school. The omission of a questionnaire led to a lack of information about the number of hours spent daily on the computer or playing specific sports. As well, the sample in this study represents one group and may not necessarily be applicable to all populations. The head, shoulder, and lumbar spine work together for daily functions. Taking this into consideration, future studies should address the sagittal posture of the lumbar spine.
CONCLUSION This study showed that forward head posture and protracted shoulder were common postural disorders in adolescents aged 15 to 17 years who participated in this study. Females demonstrated a smaller mean sagittal head and cervical angle. The results of the present study showed that photographic measurement is a reliable tool to assess the standing sagittal posture of the cervical spine and shoulder.
FUNDING SOURCES
AND
CONFLICTS
OF INTEREST
This study was supported by the Foundation for Science and Technology Portugal (grant SFRH/BD/77633/2011). No conflicts of interest were reported for this study.
CONTRIBUTORSHIP INFORMATION Concept development (provided idea for the research): R.R., P.P. Design (planned the methods to generate the results): R.R. Supervision (provided oversight, responsible for organization and implementation, writing of the manuscript): R.R., P.P. Data collection/processing (responsible for experiments, patient management, organization, or reporting data): R.R. Analysis/interpretation (responsible for statistical analysis, evaluation, and presentation of the results): R.R., A.I. Literature search (performed the literature search): R.R. Writing (responsible for writing a substantive part of the manuscript): R.R. Critical review (revised manuscript for intellectual content; this does not relate to spelling and grammar checking): R.R., P.P., A.I.
• Forward head and rounded shoulder were common postural disorders in this group of adolescents. • Forward head carriage was more common in young females. • Intrarater reliability was very good for all measures except for the cervical angle.
REFERENCES 1. Gangnet N, Pomero V, Dumas R, Skalli W, Vital J-M. Variability of the spine and pelvis location with respect to the gravity line: a three-dimensional stereoradiographic study using a force platform. Surg Radiol Anat 2003;25(5-6):424-33 [cited 2012 Dec 19, Available from: http://www.ncbi.nlm. nih.gov/pubmed/13680185]. 2. McEvoy MP, Grimmer K. Reliability of upright posture measurements in primary school children. BMC Musculoskelet Disord 2005;6:35 [cited 2012 Nov 2, Available from: http://www.pubmedcentral.nih.gov/articlerender.fcgi? artid=1180447&tool=pmcentrez&rendertype=abstract]. 3. Pausić J, Pedisić Z, Dizdar D. Reliability of a photographic method for assessing standing posture of elementary school students. J Manipulative Physiol Ther 2010;33(6):425-31 [National University of Health Sciences, [cited 2012 Nov 2], Available from: http:// www.ncbi.nlm.nih.gov/pubmed/20732579]. 4. Van Niekerk S-M, 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;9:113 [cited 2012 Nov 2, Available from: http://www.pubmedcentral.nih.gov/articlerender. fcgi?artid=2542508&tool=pmcentrez&rendertype=abstract]. 5. Detsch C, Luz AMH, Candotti CT, et al. Prevalência de alterações posturais em escolares do ensino médio em uma cidade no Sul do Brasil. Rev Panam Salud Publica 2007;21(4):231-8 Available from: http://www.scielosp.org/ scielo.php?script=sci_arttext&pid=S1020-49892007 000300006&lng=pt&nrm=iso&tlng=pt. 6. Perry M, Smith A, Straker L, Coleman J, O’Sullivan P. Reliability of sagittal photographic spinal posture assessment in adolescents. Adv Physiother 2008;10(2):66-75 [cited 2012 Nov 2, Available from: http://informahealthcare.com/doi/abs/ 10.1080/14038190701728251]. 7. Szeto GPY, Straker L, Raine S. A field comparison of neck and shoulder postures in symptomatic and asymptomatic office workers. Appl Ergon 2002;33(1):75-84 [Available from: http://www.ncbi.nlm.nih.gov/pubmed/11831210]. 8. Barczyk-Pawelec K, Sipko T, Demczuk-Włodarczyk E, Boczar A. Anterioposterior spinal curvatures and magnitude of asymmetry in the trunk in musicians playing the violin compared with nonmusicians. J Manipulative Physiol Ther 2012;35(4):319-26 [cited 2013 Aug 30, Available from: http://www.ncbi.nlm.nih.gov/pubmed/22632592]. 9. Diepenmaat a CM, van der Wal MF, de Vet HCW, Hirasing RA. Neck/shoulder, low back, and arm pain in relation to computer use, physical activity, stress, and depression among Dutch adolescents. Pediatrics 2006;117(2):412-6 [cited 2012 Nov 2, Available from: http://www.ncbi.nlm.nih.gov/ pubmed/16452360].
79
80
Ruivo et al Standing Posture of Adolescents
10. Ferreira EAG, Duarte M, Maldonado EP, Burke TN, Marques AP. Postural assessment software (PAS/SAPO): validation and reliability. Clinics (Sao Paulo) 2010;65(7):675-81 [cited 2012 Nov 2, Available from: http://www.pubmedcentral.nih.gov/articlerender. fcgi?artid=2910855&tool=pmcentrez&rendertype=abstract]. 11. De Oliveira Pezzan PA, João SM a, Ribeiro AP, Manfio EF. Postural assessment of lumbar lordosis and pelvic alignment angles in adolescent users and nonusers of high-heeled shoes. J Manipulative Physiol Ther 2011;34(9):614-21 [cited 2013 Aug 30, Available from: http://www.ncbi.nlm.nih.gov/pubmed/22078999]. 12. Ferreira E a, Duarte M, Maldonado EP, Bersanetti A a, Marques AP. Quantitative assessment of postural alignment in young adults based on photographs of anterior, posterior, and lateral views. J Manipulative Physiol Ther 2012;34(6):371-80 [National University of Health Sciences, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih.gov/pubmed/21807260]. 13. Lynch SS, Thigpen C a, Mihalik JP, Prentice WE, Padua D. The effects of an exercise intervention on forward head and rounded shoulder postures in elite swimmers. Br J Sports Med 2010;44(5):376-81 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/20371564]. 14. Diab A a, Moustafa IM. The efficacy of forward head correction on nerve root function and pain in cervical spondylotic radiculopathy: a randomized trial. Clin Rehabil 2012;26(4):351-61 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/21937526]. 15. Yip CHT, Chiu TTW, Poon ATK. The relationship between head posture and severity and disability of patients with neck pain. Man Ther 2008;13(2):148-54 [cited 2012 Oct 25, Available from: http://www.ncbi.nlm.nih.gov/pubmed/17368075]. 16. Falla D, Jull G, Russell T, Vicenzino B, Hodges P. Effect of neck exercise on sitting. Phys Ther 2007;87(4):408-17. 17. Chansirinukor W, Wilson D, Grimmer K, Dansie B. Effects of backpacks on students: measurement of cervical and shoulder posture. Aust J Physiother 2001;47(2):110-6 [Available from: http://www.ncbi.nlm.nih.gov/pubmed/11552866]. 18. Raine S, Twomey LT. Head and shoulder posture variations women and men. Arch Phys Med Rehabil 1997;78(11):1215-23. 19. Brink Y, Crous LC, Louw QA, Grimmer-Somers K, Schreve K. The association between postural alignment and psychosocial factors to upper quadrant pain in high school students: a prospective study. Man Ther 2009;14(6):647-53 [Elsevier Ltd, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih. gov/pubmed/19443260]. 20. Thigpen C a, Padua D a, Michener L a, et al. Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks. J Electromyogr Kinesiol 2010;20 (4):701-9 [Elsevier Ltd, [cited 2012 Oct 26], Available from: http://www.ncbi.nlm.nih.gov/pubmed/20097090]. 21. Harman K, Hubley-Kozey C, Butler H. Effectiveness of an exercise program to improve forward head posture in normal adults: a randomized, controlled 10-week trial. J Man Manip Ther 2005;13:163-76. 22. Bland JM, Altman DG. Comparing methods of measurement: why plotting difference against standard method is misleading. Lancet 1995;346:1085-7. 23. Ramprasad M, Alias J, Raghuveer a K. Effect of backpack weight on postural angles in preadolescent children. Indian Pediatr 2010;47(7):575-80 [Available from: http://www.ncbi. nlm.nih.gov/pubmed/20019396]. 24. Murphy S, Buckle P, Stubbs D. Classroom posture and selfreported back and neck pain in schoolchildren. Appl Ergon 2004;35(2):113-20 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/15105072].
Journal of Manipulative and Physiological Therapeutics January 2015
25. Prins Y, Crous L, Louw Q a. A systematic review of posture and psychosocial factors as contributors to upper quadrant musculoskeletal pain in children and adolescents. Physiother Theory Pract 2008;24(4):221-42 [cited 2012 Nov 2, Available from: http://www.ncbi.nlm.nih.gov/pubmed/18574749]. 26. Silva AG, Punt TD, Sharples P, Vilas-Boas JP, Johnson MI. Head posture and neck pain of chronic nontraumatic origin: a comparison between patients and pain-free persons. Arch Phys Med Rehabil 2009;90(4):669-74 [the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih.gov/pubmed/19345785]. 27. Helgadottir H, Kristjansson E, Mottram S, Karduna A, Jonsson H. Altered alignment of the shoulder girdle and cervical spine in patients with insidious onset neck pain and whiplash-associated disorder. J Appl Biomech 2011;27 (3):181-91 [Available from: http://www.ncbi.nlm.nih.gov/ pubmed/21844606]. 28. De Wall M, Van Riel MPJM, Aghina J C F M, BurdorfF A, Snijders CJ. Improving the sitting posture of CAD/CAM workers by increasing VDU monitor working height. Ergonomics 1992(35):427-36. 29. Wang C, Mcclure P, Pratt NE, Nobilini R. Stretching and strengthening exercises: their effect on three-dimensional scapular kinematics. Arch Phys Med Rehabil 1999;80(8):923-9. 30. McClure PW, Michener LA, Karduna AR. Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome. Phys Ther 2006;86: 1075-90. 31. Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Phys Ther 2000;80(3):276-91. 32. Brattberg G. Do pain problems in young school children persist into early adulthood? A 13-year follow-up. Eur J Pain 2004;8(3):187-99 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/15109969]. 33. Croft PR, Lewis M, Papageorgiou a C, et al. Risk factors for neck pain: a longitudinal study in the general population. Pain 2001;93(3):317-25 [Available from: http://www.ncbi.nlm. nih.gov/pubmed/11514090]. 34. Grimmer K a, Williams MT, Gill TK. The associations between adolescent head-on-neck posture, backpack weight, and anthropometric features. Spine (Phila Pa 1976) 1999;24 (21):2262-7 [Available from: http://www.ncbi.nlm.nih.gov/ pubmed/10562994]. 35. Briggs A, Straker L, Greig A. Upper quadrant postural changes of school children in response to interaction with different information technologies. [Internet]Ergonomics 2004:790-819 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/15204289]. 36. Dalton M CA. The effect of age on cervical posture in a normal population. In: Boyling JD, Palastanga N E, Grieve’s M, editors. New York: Churchill Livingstone; 1994. 37. Lau KT, Cheung KY, Chan KB, Chan MH, Lo KY, Chiu TTW. Relationships between sagittal postures of thoracic and cervical spine, presence of neck pain, neck pain severity and disability. Man Ther 2010;15(5):457-62 [Elsevier Ltd, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih.gov/ pubmed/20430685]. 38. Ståhl M, Mikkelsson M, Kautiainen H, Häkkinen A, Ylinen J, Salminen JJ. Neck pain in adolescence. A 4-year follow-up of pain-free preadolescents. Pain 2004;110(1-2):427-31 [cited 2012 Nov 2, Available from: http://www.ncbi.nlm.nih.gov/ pubmed/15275795].
ABSTRACT Objective: The purposes of this study were to determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and analyze differences in postural angles between sexes. Methods: This cross-sectional study was conducted in 2 secondary schools in Portugal where 275 adolescent students (146 females and 129 males) aged 15 to 17 years were evaluated. Sagittal head, cervical, and shoulder angles were measured with photogrammetry and the Postural Assessment Software. Results: For interrater reliability, all of the intraclass correlation coefficient (ICC) values for the 3 angles were higher than 0.85. For intrarater reliability, the ICC values for the sagittal head angle, shoulder angle, and cervical angle were 0.83, 0.78, and 0.66, respectively. Mean values of sagittal head, cervical, and shoulder angles were 17.2° ± 5.7°, 47.4° ± 5.2°, and 51.4° ± 8.5°, respectively. Anterior head carriage was demonstrated by 68% of the adolescents, whereas 58% had protraction of the shoulder(s). Males had significantly higher mean cervical and sagittal head angles. Conclusions: Forward head posture and protracted shoulders were common postural disorders in adolescents 15 to 17 years old, with females revealing a lower mean cervical angle. The intrarater and interrater evaluation of standing sagittal posture of the cervical spine and shoulders by photogrammetry was reliable. (J Manipulative Physiol Ther 2015;38:74-80) Key Indexing Terms: Adolescent; Head; Photogrammetry; Posture; Shoulder
osture has been defined as the alignment of the body segments at a particular time 1 and is an important health indicator. 2 it is believed that an efficient, erect human posture should allow for the maintenance of balance using the least musculoskeletal effort without a feeling of discomfort. 3 Epidemiological studies have shown a high prevalence of spinal postural deviations in children and adolescents. 4,5 Other outcome studies have shown that musculoskeletal pain has become a major symptomatic complaint among
P a
Assistant, Faculdade de Motricidade Humana, Lisboa, Portugal. Professor, Faculdade de Motricidade Humana, Universidade de Lisboa, Laboratório de Comportamento Motor, Lisboa, Portugal. c Professor, Faculdade de Motricidade Humana, Universidade de Lisboa, Secção Autónoma de Métodos Matemáticos, Lisboa, Portugal. Submit requests for reprints to: R.M. Ruivo, MsC, Assistant, Avenida Fernando Pessoa, lote 3.20.01, Bloco B, 4 A, 1990-102 Lisbon, Portugal. (e-mail: [email protected]). Paper submitted December 29, 2013; in revised form August 17, 2014; accepted August 25, 2014. 0161-4754 Copyright © 2015 by National University of Health Sciences. http://dx.doi.org/10.1016/j.jmpt.2014.10.009 b
children and adolescents. The shoulder and neck regions are cited in many references as the areas of greatest discomfort in adults and adolescents. 6–8 For example, Perry et al 6 and Diepenmaat et al 9 reported that the monthly prevalence rates for adolescent neck and shoulder pain are increasing and range between 11.5% and 29%. Postural assessment through photography may be a simple method that allows the acquisition of quantitative values to define the alignment of body segments. Recent technological improvements have paved the way for the development of reliable and applicable methods to assist in adolescent postural assessment, such as computer-assisted systems for the analysis of posture photographs (photogrammetry). 2,10 This method has become widely used in the quantitative assessment of postural alignment, with the potential to quantify linear and angular measurements and with the advantage of allowing a record of subtle postural changes and the interrelation between different parts of the human body, 11 which are difficult to measure and register by other means. Specific software has been developed to assist with posture assessment from digitalized pictures, such as the Postural Assessment Software (PAS/SAPO) 10, 12.
Journal of Manipulative and Physiological Therapeutics Volume 38, Number 1
With a quantitative postural assessment method based on the measurement of different postural angles, it may be possible to identify postural problems such as forward head posture and protracted shoulder. Forward head posture includes cervical spine hyperextension and is associated with the shortening of the upper trapezius, the posterior cervical extensor muscles (suboccipital, semispinalis, and splenni), the sternocleidomastoid muscle, and the levator scapulae musculature. 13 This postural deviation can be studied based on the cervical angle, 4,14 which represents the angle formed at the intersection of a horizontal line through the spinous process of C7 and a line to the tragus of the ear, with smaller angles indicating a more forward head posture. Very often, 50° is chosen as a reference angle 14; and an individual is considered to have forward head posture if the angle is lower than that value. A protracted shoulder is a forward displacement of the acromion with reference to the seventh cervical spinous process and can be measured by the shoulder angle. It represents the intersection of the line between the midpoint of the humerus (or acromion process) and spinous process of C7 and the horizontal line through the midpoint of the humerus. Taking into account the importance of measuring postural deviations, the purposes of the present study were 3-fold: (1) determine the intrarater and interrater reliability of a photographic measurement of the sagittal postures of the cervical spine and shoulder, (2) quantitatively characterize the postural alignment of the head and shoulders in the sagittal plane of Portuguese adolescents 15 to 17 years old in natural erect standing, and (3) analyze differences in postural angles between sexes.
METHODS Ethics The study was approved by the Research Ethics Committee of the Faculty of Human Kinetics of the Technical University of Lisbon. The participation of all students was voluntary, and written informed consent was obtained from all participants and their parents or legal guardians.
Setting This cross-sectional study was conducted in 2 public secondary schools, Lumiar Secondary School and Padre Antonio Vieira Secondary School, located in the city of Lisbon, Portugal. The choice of these schools was based on geographical issues and focused on the center of Lisbon.
Participants Male and female adolescent students between the ages of 15 and 17 years were eligible to participate. Participants were excluded if they had visual deficits, had diagnosed balance disorders, or were nonambulatory. Additional
Ruivo et al Standing Posture of Adolescents
Fig 1. Sagittal head angle, cervical angle, and shoulder angle. exclusion criteria were the presence of musculoskeletal pathologies, such as a history of shoulder surgery, current shoulder pain limiting activities, cervical or thoracic fracture, displayed functional or structural scoliosis, or excessive thoracic kyphosis. Given these criteria, a total of 275 adolescent students (146 females and 129 males) aged 15, 16, or 17 years old (15.76 ± 1.08 years) from 17 different classes (9 from the 10th grade, 7 from the 11th grade, and 1 from the 12th grade) were evaluated and included in the study.
Procedures Standing cervical and shoulder posture was measured with photogrammetry and PAS. Three angles of measurement were used: sagittal head angle, cervical angle, and shoulder angle. We chose these angles because they had been used in previous studies and were found to be reliable, 4 enabling the comparison of results. The angles (Fig 1) in the sagittal view were obtained as follows: Sagittal Head Angle. It is the angle formed at the intersection of a horizontal line through the tragus of the ear and a line joining the tragus of the ear and the external canthus of the eye. Cervical Angle. The cervical angle is used to assess the forward position. 4,14 It is the angle formed at the intersection of a horizontal line through the spinous process of C7 and a line to the tragus of the ear. In this study, if the angle was less than 50°, the participant was considered to have forward head posture. The selection of 50° as a reference angle was guided by the studies of Diab and Moustafa 14 and Yip et al, 15 with the latter reporting 55.02 ± 2.86 as a reference range. As is well known, participants
75
76
Ruivo et al Standing Posture of Adolescents
with forward head posture have a significantly smaller cervical angle when compared with healthy participants. 16 Shoulder Angle. It is the angle formed at the intersection of the line between the midpoint of the humerus and spinous process of C7 and the horizontal line through the midpoint of the humerus. Based on the premise that participants with protracted shoulder have a significantly smaller shoulder angle when compared with healthy participants, 17,18 considering a study by Brink et al 19 with adolescents 15 to 17 years old reporting a mean shoulder angle value of 51.35° ± 17.2°, a study by Thigpen et al 20 with 310 participants evaluated in a standing position that reported 52.6 ± 15.3 as a reference range, and a study by Raine and Twomey 18 with 160 participants evaluated in a standing position that reported 54.3° ± 11.5° as a reference range, we considered 52° as the reference angle. We considered an individual to have protracted shoulder (PS) if the angle was less than 52°. In the article of Thigpen et al (2010), the shoulder angle mentioned above was measured using a vertical line as a reference. However, to normalize the reading of the database, the horizontal line was considered as a reference. All measurements were performed by the same researcher who was experienced in the assessment of postural alignment. The photographing took place in the gymnasium of the 2 secondary schools with the areas arranged identically. Efforts were made to control the temperature, noise, and distractions. Landmarks were placed on the floor to ensure the same positioning of all participants in front of the camera, and the participant was aligned perpendicular to the camera. A landmark was placed in front of a white wall to ensure contrast of the participants against the background. One Canon Power Shot A4000 IS (Canon, Suzhou, China) was supported on a Manfrotto tripod, model 055 CLB (Tokyo, Japan), 3 m away from the line marking the position of the participant. The height of the tripod was adjusted so that the middle of the objective lens was 130 cm above the ground. A calibration board was placed on the white wall in the field of view and aligned with the participant to allow referencing of horizontal and vertical axes from the photographs. The calibration board also displayed each participant's identification number. For positioning, the adolescent was instructed to stand comfortably in a normal standing position and to look straight ahead. Marks on the floor ensured that all participants were placed in the same place. Before photographing, the researcher put reflective markers on the following anatomical points on the right side of the participant’s body: tragus of the ear, lateral canthus of the eye, the spinous process of C7, and midpoint of the humerus. With these markers, we were able to calculate the sagittal head angle, cervical angle, and shoulder angle. To enable precise positioning of the markers, we instructed the participants to wear tight shorts and sleeveless T-shirts, with an elastic for the hair when needed. The procedure was performed by the same researcher.
Journal of Manipulative and Physiological Therapeutics January 2015
To capture the participant’s natural head-on-trunk and shoulder alignment, each person was asked to look straight ahead and to march on the spot 5 times before each picture was taken. 21 Each picture was taken within 5 seconds of the marching sequence in a lateral view, with the right side of the participant photographed for the right-hand dominant individuals and the left side for the left-hand dominants. The dominant arm was defined as the one most used in daily activities. The investigator checked for the sagittal position of each participant to correct for segmental rotation before taking the photograph. The photographic analysis was subsequently performed using software for postural analysis (PAS), which determined the coordinates of the anatomical points on the photographs. The zoom was standardized at 200%, and the angles were measured in degrees. One researcher undertook all scanning and digitizing to eliminate interexaminer error. The data were submitted for descriptive statistical analysis, and quantitative values for head and upper member angles were obtained.
Reliability Study A separate preparatory study to confirm the inter- and intrarater reliability of computerized photogrammetry using the PAS was performed. The study sample consisted of 17 participants from a 10th-grade class. Three physical therapists (all men from 26 to 32 years old) who were not regular users of the PAS/SAPO but had used the software before were invited to participate as raters. Each student was photographed in precise conditions, and pictures were taken of the participants in random order. Using the PAS/ SAPO, raters performed the measurements. These procedures were repeated 1 week later, and the results were compared to assess the intrarater reliability.
Statistical Analysis All statistical analyses were performed using specific software (SPSS version 20, Chicago, IL), and the statistical significance level was defined as P b .05. Reliability was determined from the intraclass correlation coefficients (ICCs) by means of the 2-way model. The scale from Bland and Altman 22 was used in the classification of the reliability values. Intraclass correlation coefficient values less than or equal to 0.20 were considered poor, 0.21 to 0.40 was considered fair, 0.41 to 0.60 was considered moderate, 0.61 to 0.80 was considered good, and 0.81 to 1 was considered very good. Standard error of measurement (SEM) was used to examine the precision of the measurement and was calculated according to SEM = SD√1 − ICC. In the experimental study, the data were analyzed using descriptive statistics such as the mean, standard deviation, and percentage. The Shapiro-Wilk test was used to assess normality. To analyze differences between sexes in the 3 postural angles, an independent-samples t test was applied.
Journal of Manipulative and Physiological Therapeutics Volume 38, Number 1
Ruivo et al Standing Posture of Adolescents
Table 1. Intrarater and Interrater Reliability Findings: ICC and SEM Values for All Angles Intrarater Reliability Measurement
ICC (95% CI)
Measurement
Adolescents (Mean ± SD) N =275 (146 Female and 129 Male)
Age (y) Sagittal head tilt angle (°) Cervical angle (°) Shoulder angle (°)
15.76 ± 1.08 17.15 ± 5.74 47.39 ± 5.17 51.44 ± 8.55
Interrater Reliability
SEM ICC (95% CI)
Sagittal head angle 0.83 (0.60-0.94) 2.72 Cervical angle 0.66 (0.26-0.87) 3.54 Shoulder angle 0.78 (0.49-0.92) 4.03
Table 2. Demographic Characteristics of Participants and Descriptive Values for the Postural Angles (N = 275)
SEM
0.88 (0.75-0.95) 2.35 0.87 (0.74-0.95) 1.85 0.96 (0.92-0.99) 1.64
CI, confidence interval; ICC, intraclass correlation coefficient; SEM, standard error of measurement.
Relationships between the 3 postural angles were examined by calculating the Pearson r correlation coefficients (rs).
RESULTS Reliability Study The reliability of the photographic measurements is shown in Table 1. A total of 17 participants (14 females and 3 males) aged 15 to 17 years were recruited for the reliability study. The ICC values for the sagittal head angle (0.83) revealed very good reliability, whereas the values for the shoulder angle and for the cervical angle reported good reliability, with 0.78 and 0.66, respectively. All of the ICC values for the 3 angles reported very good interrater reliability, with the SEMs of the photographic measurement ranging between 1.64 and 2.35.
Experimental Study Sample Description. The demographic characteristics of the participants and descriptive values for the 3 postural angles are described in Table 2. With the aid of the photogrammetry and taking into consideration the reference values outlined previously, of the 275 students studied, 188 were found to have forward head (FH) with a cervical angle lower than 50°, whereas 131 of them had a shoulder angle less than 52°, revealing a PS. Only 47 students (17%) had no forward head posture or protracted shoulder, and 131 students (47, 6%) had both FH and PS. All of these values are shown in Figure 2. Differences Between Sexes on Postural Angle. The examination of the head and shoulder posture measurements to identify sex differences between males and females using an independent-samples t test is reported in Table 3. Significant differences were observed between males and females with respect to the sagittal head angle and the cervical angle, with males having a higher mean value (18.4 ± 6.03 vs 16.15 ± 5.31 and 48.43 ± 4.91 vs 46.55 ± 5.24, respectively).
DISCUSSION Reliability Study The present study demonstrated very good reliability for the interrater measurements in the same image for all of the variables studied, with ICC values greater than 0.90 and
Fig 2. Percentage of students demonstrating forward head and/or protracted shoulders. FH, forward head; FHP, forward head posture; PS, protracted shoulder. low values of SEM (1.64-2.35). These results are in line with the values found by Falla et al. 16 Regarding the intrarater reliability, for the sagittal head angle and shoulder angle, the ICC values revealed very good and good reliability; and the cervical angle demonstrated good reliability in the normal standing posture with the second highest SEM value. With these data, we can suggest that the adolescents’ upper quadrant standing posture (quantified by 3 segmental angles) did not change significantly with repeated testing. The same finding was reported by McEvoy and Grimmer al 2 with children (5-12 years) and for all body angles (quantified by 5 whole-body or segmental angles).
Postural Study Descriptive Statistics. There is sparse literature providing evidence of cervical and shoulder postural alignment among 15- to 17-year-old adolescents. In addition to facilitating the report of standing postural alignment for a specific and important age group, this study has the advantage of evaluating a far larger sample than others 4,17 and analyzing sex differences. In this study, a large percentage of the participants displayed some degree of postural abnormality in the cervical and/or shoulder region: 68% and 58% of the students had FH and PS, respectively, whereas 47.6% of the total sample had both misalignments. The incorrect use of heavy backpacks, 23 the lack of ergonomy of the school furniture, 24 psychosocial factors such as depression or stress, 25 and the practice of spending many hours seated with incorrect posture in school and in
77
78
Ruivo et al Standing Posture of Adolescents
Journal of Manipulative and Physiological Therapeutics January 2015
Table 3. Effect of Sex on the 3 Postural Angles Measurement Sagittal head tilt angle (°) ⁎ Cervical angle (°) ⁎ Shoulder angle (°)
Females (n=153)
Males (n=122)
Independent-Samples t Test
Mean
SD
Mean
SD
t
P
16.15 46.55 51.09
5.31 5.24 8.28
18.48 48.44 51.9
6.03 4.91 8.92
− 3.3 − 3.05 − 0.77
.001 .002 .445
⁎ Statistically significant difference (P b .05).
front of computers and televisions 19 may be responsible for this finding. Specifying the angles studied, in this study, we chose the sagittal head, cervical, and shoulder angles because they are the most frequently cited in the literature, enabling the comparison of results. These analyses help us to characterize the posture of a patient regarding the head and shoulder position, and they are reliable. 26 For example, the cervical angle is highly reliable to assess the forward head position. 4 The sagittal head angle measures the alignment of the upper cervical spine. 27 The mean head tilt angle registered (17.15° [5.7]) is similar to a study by Chansirinukor et al 17 with adolescents (13-16 years old) in standing position, which reported a mean sagittal head angle of 16.3°. In other studies, Brink et al 19 studied 107 adolescents (15-17 years old) and reported a mean value of 13.8°, whereas Van Niekerk et al 4 studied a sample of 40 adolescents (16-17 years old) and described a mean value of 20.1°. In both studies, adolescents were evaluated in a seated position. De Wall et al 28 recommended that a suitable head tilt angle would be 15° above the horizontal. For the cervical angle, a smaller angle indicates a more FHP. 14 The mean CV angle obtained, 47.4° (5.17), is similar to the one reported by Van Niekerk et al, 4 47.6 (9.75), who evaluated 40 16- to 17-year-old adolescents. In another study of 94 students aged 15 to 17 years old, Brink et al 19 found a smaller cervical angle, 39.27 (7.9), which they considered the cause of upper quadrant pain. The shoulder angle is an angle that provides a measurement of the shoulder position. The mean shoulder angle obtained, 51.44° (8.56), is similar to the one found in the study of Brink et al 19 (51.35° [17.2]) and is slightly higher than the one found in Van Niekerk et al 4 (49.79° [25.7]). Both studies evaluated adolescents. A smaller angle indicates a protracted shoulder, which is frequently associated with a protracted, anterior tilted, and internally rotated scapula and with a tightness of the pectoralis minor muscle. 29 These shoulder alterations, which are also related to a decreased serratus anterior and lower trapezius activity, are associated with many clinical syndromes involving the shoulder 30,31 and with a reduced subacromial space. Postural deviations such as protracted shoulder and forward head posture are becoming common in adolescents 5 and can lead to upper quadrant musculoskeletal pain that can persist into adulthood. 19,32 As noted by Croft et al, 33 prior neck/shoulder pain is a strong risk factor for future neck/
shoulder pain in adults, with the consequent high economic cost of treating these symptoms. 25 Based on these premises, it becomes clear that something must be done to counteract this situation. Postural training and rehabilitation with the aim of preventing and managing upper quadrant musculoskeletal pain should be implemented at early ages, and schools and physical education classes may play an important role in this issue.
Differences Between Sexes on Postural Angles. After analyzing sex differences, females had a lower resting cervical angle than males (46.55° vs 48.44°). This finding is in accordance with Grimmer et al, 34 whose study of standing cervical habitual posture in adolescents found that females had 2° to 3° more neck flexion than males. 35 Briggs et al 35 proposed that this observation may be partly attributable to psychosocial issues associated with the development of secondary sex characteristics in females preceding those of males. In adults’ resting head-on-neck posture, significant sex differences in cervical angle have been observed, including a more forward head posture in women. 36 In contrast to the current study, 2 small-sample studies have reported no sex differences for cervical habitual posture in adolescents and preadolescents. 2,4 More research is required to clarify the role of sex in cervical posture. Correlating the cervical angle obtained in this study with pain and based on the premise that participants with neck pain have a significantly smaller cervical angle compared with healthy participants, 37 it can be hypothesized that young females would have more cervical pain. This hypothesis is in accordance with many other studies that have reported more neck pain in young females than in young males. 9,38 Regarding the shoulder angle, comparative studies of young males and females are much rarer. Similar to this study, with an adult sample, Raine and Twomey 18 found similar shoulder positions with respect to the seventh cervical in the sagittal plane for men and women. Regarding sex differences, it would be advisable and interesting in a future study to establish a relationship between head and shoulder postural deviations and the severity and frequency of pain in the upper quadrant region. Further studies should also address the evaluation of the effects of a training program applied in physical education classes in school on sagittal cervical shoulder posture in adolescents.
Journal of Manipulative and Physiological Therapeutics Volume 38, Number 1
Ruivo et al Standing Posture of Adolescents
LIMITATIONS Practical Applications One of the limitations of this study is that it describes only the alignment of the spine and the shoulder girdle at rest. Therefore, the findings cannot be generalized to alignment during functional tasks, especially when the upper limb is moving or loaded. This is also the case when activities are prolonged over time. Although this study aimed to minimize errors and bias in all procedures and setups, to obtain even better precision, future studies should apply a questionnaire on lifestyle habits at home and at school. The omission of a questionnaire led to a lack of information about the number of hours spent daily on the computer or playing specific sports. As well, the sample in this study represents one group and may not necessarily be applicable to all populations. The head, shoulder, and lumbar spine work together for daily functions. Taking this into consideration, future studies should address the sagittal posture of the lumbar spine.
CONCLUSION This study showed that forward head posture and protracted shoulder were common postural disorders in adolescents aged 15 to 17 years who participated in this study. Females demonstrated a smaller mean sagittal head and cervical angle. The results of the present study showed that photographic measurement is a reliable tool to assess the standing sagittal posture of the cervical spine and shoulder.
FUNDING SOURCES
AND
CONFLICTS
OF INTEREST
This study was supported by the Foundation for Science and Technology Portugal (grant SFRH/BD/77633/2011). No conflicts of interest were reported for this study.
CONTRIBUTORSHIP INFORMATION Concept development (provided idea for the research): R.R., P.P. Design (planned the methods to generate the results): R.R. Supervision (provided oversight, responsible for organization and implementation, writing of the manuscript): R.R., P.P. Data collection/processing (responsible for experiments, patient management, organization, or reporting data): R.R. Analysis/interpretation (responsible for statistical analysis, evaluation, and presentation of the results): R.R., A.I. Literature search (performed the literature search): R.R. Writing (responsible for writing a substantive part of the manuscript): R.R. Critical review (revised manuscript for intellectual content; this does not relate to spelling and grammar checking): R.R., P.P., A.I.
• Forward head and rounded shoulder were common postural disorders in this group of adolescents. • Forward head carriage was more common in young females. • Intrarater reliability was very good for all measures except for the cervical angle.
REFERENCES 1. Gangnet N, Pomero V, Dumas R, Skalli W, Vital J-M. Variability of the spine and pelvis location with respect to the gravity line: a three-dimensional stereoradiographic study using a force platform. Surg Radiol Anat 2003;25(5-6):424-33 [cited 2012 Dec 19, Available from: http://www.ncbi.nlm. nih.gov/pubmed/13680185]. 2. McEvoy MP, Grimmer K. Reliability of upright posture measurements in primary school children. BMC Musculoskelet Disord 2005;6:35 [cited 2012 Nov 2, Available from: http://www.pubmedcentral.nih.gov/articlerender.fcgi? artid=1180447&tool=pmcentrez&rendertype=abstract]. 3. Pausić J, Pedisić Z, Dizdar D. Reliability of a photographic method for assessing standing posture of elementary school students. J Manipulative Physiol Ther 2010;33(6):425-31 [National University of Health Sciences, [cited 2012 Nov 2], Available from: http:// www.ncbi.nlm.nih.gov/pubmed/20732579]. 4. Van Niekerk S-M, 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;9:113 [cited 2012 Nov 2, Available from: http://www.pubmedcentral.nih.gov/articlerender. fcgi?artid=2542508&tool=pmcentrez&rendertype=abstract]. 5. Detsch C, Luz AMH, Candotti CT, et al. Prevalência de alterações posturais em escolares do ensino médio em uma cidade no Sul do Brasil. Rev Panam Salud Publica 2007;21(4):231-8 Available from: http://www.scielosp.org/ scielo.php?script=sci_arttext&pid=S1020-49892007 000300006&lng=pt&nrm=iso&tlng=pt. 6. Perry M, Smith A, Straker L, Coleman J, O’Sullivan P. Reliability of sagittal photographic spinal posture assessment in adolescents. Adv Physiother 2008;10(2):66-75 [cited 2012 Nov 2, Available from: http://informahealthcare.com/doi/abs/ 10.1080/14038190701728251]. 7. Szeto GPY, Straker L, Raine S. A field comparison of neck and shoulder postures in symptomatic and asymptomatic office workers. Appl Ergon 2002;33(1):75-84 [Available from: http://www.ncbi.nlm.nih.gov/pubmed/11831210]. 8. Barczyk-Pawelec K, Sipko T, Demczuk-Włodarczyk E, Boczar A. Anterioposterior spinal curvatures and magnitude of asymmetry in the trunk in musicians playing the violin compared with nonmusicians. J Manipulative Physiol Ther 2012;35(4):319-26 [cited 2013 Aug 30, Available from: http://www.ncbi.nlm.nih.gov/pubmed/22632592]. 9. Diepenmaat a CM, van der Wal MF, de Vet HCW, Hirasing RA. Neck/shoulder, low back, and arm pain in relation to computer use, physical activity, stress, and depression among Dutch adolescents. Pediatrics 2006;117(2):412-6 [cited 2012 Nov 2, Available from: http://www.ncbi.nlm.nih.gov/ pubmed/16452360].
79
80
Ruivo et al Standing Posture of Adolescents
10. Ferreira EAG, Duarte M, Maldonado EP, Burke TN, Marques AP. Postural assessment software (PAS/SAPO): validation and reliability. Clinics (Sao Paulo) 2010;65(7):675-81 [cited 2012 Nov 2, Available from: http://www.pubmedcentral.nih.gov/articlerender. fcgi?artid=2910855&tool=pmcentrez&rendertype=abstract]. 11. De Oliveira Pezzan PA, João SM a, Ribeiro AP, Manfio EF. Postural assessment of lumbar lordosis and pelvic alignment angles in adolescent users and nonusers of high-heeled shoes. J Manipulative Physiol Ther 2011;34(9):614-21 [cited 2013 Aug 30, Available from: http://www.ncbi.nlm.nih.gov/pubmed/22078999]. 12. Ferreira E a, Duarte M, Maldonado EP, Bersanetti A a, Marques AP. Quantitative assessment of postural alignment in young adults based on photographs of anterior, posterior, and lateral views. J Manipulative Physiol Ther 2012;34(6):371-80 [National University of Health Sciences, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih.gov/pubmed/21807260]. 13. Lynch SS, Thigpen C a, Mihalik JP, Prentice WE, Padua D. The effects of an exercise intervention on forward head and rounded shoulder postures in elite swimmers. Br J Sports Med 2010;44(5):376-81 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/20371564]. 14. Diab A a, Moustafa IM. The efficacy of forward head correction on nerve root function and pain in cervical spondylotic radiculopathy: a randomized trial. Clin Rehabil 2012;26(4):351-61 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/21937526]. 15. Yip CHT, Chiu TTW, Poon ATK. The relationship between head posture and severity and disability of patients with neck pain. Man Ther 2008;13(2):148-54 [cited 2012 Oct 25, Available from: http://www.ncbi.nlm.nih.gov/pubmed/17368075]. 16. Falla D, Jull G, Russell T, Vicenzino B, Hodges P. Effect of neck exercise on sitting. Phys Ther 2007;87(4):408-17. 17. Chansirinukor W, Wilson D, Grimmer K, Dansie B. Effects of backpacks on students: measurement of cervical and shoulder posture. Aust J Physiother 2001;47(2):110-6 [Available from: http://www.ncbi.nlm.nih.gov/pubmed/11552866]. 18. Raine S, Twomey LT. Head and shoulder posture variations women and men. Arch Phys Med Rehabil 1997;78(11):1215-23. 19. Brink Y, Crous LC, Louw QA, Grimmer-Somers K, Schreve K. The association between postural alignment and psychosocial factors to upper quadrant pain in high school students: a prospective study. Man Ther 2009;14(6):647-53 [Elsevier Ltd, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih. gov/pubmed/19443260]. 20. Thigpen C a, Padua D a, Michener L a, et al. Head and shoulder posture affect scapular mechanics and muscle activity in overhead tasks. J Electromyogr Kinesiol 2010;20 (4):701-9 [Elsevier Ltd, [cited 2012 Oct 26], Available from: http://www.ncbi.nlm.nih.gov/pubmed/20097090]. 21. Harman K, Hubley-Kozey C, Butler H. Effectiveness of an exercise program to improve forward head posture in normal adults: a randomized, controlled 10-week trial. J Man Manip Ther 2005;13:163-76. 22. Bland JM, Altman DG. Comparing methods of measurement: why plotting difference against standard method is misleading. Lancet 1995;346:1085-7. 23. Ramprasad M, Alias J, Raghuveer a K. Effect of backpack weight on postural angles in preadolescent children. Indian Pediatr 2010;47(7):575-80 [Available from: http://www.ncbi. nlm.nih.gov/pubmed/20019396]. 24. Murphy S, Buckle P, Stubbs D. Classroom posture and selfreported back and neck pain in schoolchildren. Appl Ergon 2004;35(2):113-20 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/15105072].
Journal of Manipulative and Physiological Therapeutics January 2015
25. Prins Y, Crous L, Louw Q a. A systematic review of posture and psychosocial factors as contributors to upper quadrant musculoskeletal pain in children and adolescents. Physiother Theory Pract 2008;24(4):221-42 [cited 2012 Nov 2, Available from: http://www.ncbi.nlm.nih.gov/pubmed/18574749]. 26. Silva AG, Punt TD, Sharples P, Vilas-Boas JP, Johnson MI. Head posture and neck pain of chronic nontraumatic origin: a comparison between patients and pain-free persons. Arch Phys Med Rehabil 2009;90(4):669-74 [the American Congress of Rehabilitation Medicine and the American Academy of Physical Medicine and Rehabilitation, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih.gov/pubmed/19345785]. 27. Helgadottir H, Kristjansson E, Mottram S, Karduna A, Jonsson H. Altered alignment of the shoulder girdle and cervical spine in patients with insidious onset neck pain and whiplash-associated disorder. J Appl Biomech 2011;27 (3):181-91 [Available from: http://www.ncbi.nlm.nih.gov/ pubmed/21844606]. 28. De Wall M, Van Riel MPJM, Aghina J C F M, BurdorfF A, Snijders CJ. Improving the sitting posture of CAD/CAM workers by increasing VDU monitor working height. Ergonomics 1992(35):427-36. 29. Wang C, Mcclure P, Pratt NE, Nobilini R. Stretching and strengthening exercises: their effect on three-dimensional scapular kinematics. Arch Phys Med Rehabil 1999;80(8):923-9. 30. McClure PW, Michener LA, Karduna AR. Shoulder function and 3-dimensional scapular kinematics in people with and without shoulder impingement syndrome. Phys Ther 2006;86: 1075-90. 31. Ludewig PM, Cook TM. Alterations in shoulder kinematics and associated muscle activity in people with symptoms of shoulder impingement. Phys Ther 2000;80(3):276-91. 32. Brattberg G. Do pain problems in young school children persist into early adulthood? A 13-year follow-up. Eur J Pain 2004;8(3):187-99 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/15109969]. 33. Croft PR, Lewis M, Papageorgiou a C, et al. Risk factors for neck pain: a longitudinal study in the general population. Pain 2001;93(3):317-25 [Available from: http://www.ncbi.nlm. nih.gov/pubmed/11514090]. 34. Grimmer K a, Williams MT, Gill TK. The associations between adolescent head-on-neck posture, backpack weight, and anthropometric features. Spine (Phila Pa 1976) 1999;24 (21):2262-7 [Available from: http://www.ncbi.nlm.nih.gov/ pubmed/10562994]. 35. Briggs A, Straker L, Greig A. Upper quadrant postural changes of school children in response to interaction with different information technologies. [Internet]Ergonomics 2004:790-819 [cited 2012 Nov 2, Available from: http:// www.ncbi.nlm.nih.gov/pubmed/15204289]. 36. Dalton M CA. The effect of age on cervical posture in a normal population. In: Boyling JD, Palastanga N E, Grieve’s M, editors. New York: Churchill Livingstone; 1994. 37. Lau KT, Cheung KY, Chan KB, Chan MH, Lo KY, Chiu TTW. Relationships between sagittal postures of thoracic and cervical spine, presence of neck pain, neck pain severity and disability. Man Ther 2010;15(5):457-62 [Elsevier Ltd, [cited 2012 Nov 2], Available from: http://www.ncbi.nlm.nih.gov/ pubmed/20430685]. 38. Ståhl M, Mikkelsson M, Kautiainen H, Häkkinen A, Ylinen J, Salminen JJ. Neck pain in adolescence. A 4-year follow-up of pain-free preadolescents. Pain 2004;110(1-2):427-31 [cited 2012 Nov 2, Available from: http://www.ncbi.nlm.nih.gov/ pubmed/15275795].