RLMAR2008 Layout 12 SA JOURNAL OF PHYSIOTHERAPY 2008 VOL 64 NO 3 The Reliability and Validity of Upper Quadrant Posture and Two-dimensional Range of Motion Measurement Tools R e s e a r c h A r t i c l e 1. INTRODUCTION Good spinal posture and range of motion of the upper quadrant is recog- nised as a desirable and valid outcome of health care and is a well accepted concept in the health sciences (Vieira and Kumar 2004). Posture has been identified by researchers in the field of musculoskeletal pain to be a primary predictor of the development of spinal, particularly upper quadrant pain among computer users (Vieira and Kumar 2004, National Institute for Occupational Safety and Health). Posture is most commonly defined as the biomechanical alignment or position of the body seg- ments when performing a specific task (Vieira and Kumar 2004). Considering the practical implications of measuring posture and range of motion, evaluating the validity and reliability of posture measurement is often deemed to be a challenge in research (Harrison et al 2005). A range of postural measurement tools including the goniometer, inclino - meter, flexible electrogoniometer, flexi- curve and photography is commonly used in research projects to evaluate postural alignment. However, infor - mation about the validity and reliability of 2D upper quadrant movement and posture measurement tools is scarce. Also the selection of the most appro - priate tool for a specific research project or in the clinical setting is often difficult and time consuming (Harrison et al 2005, Christensen 1999, Nitschke et al 1999, Chen and Lee 1997). In any research design, validity and reliability of measurement tools are important elements in minimising measurement error (Vieira and Kumar 2004, Leskinen et al 1997). A lack of Correspondence to: Quinette Louw Division of Physiotherapy Department of Interdisciplinary Health Sciences Faculty of Health Sciences Stellenbosch University P O Box 19063, Tygerberg, 7505 Tel +27 (021) 938-9301 Fax: +27 (021) 931-1252 Email: qalouw@sun,ac.za A BST R A CT: Measuring upper quadrant posture and movement is a challenge to researchers and clinicians. A range of postural measurement tools is commonly used in the clinical setting and in research projects to evaluate postural align- ment, but information about the validity and reliability of these tools and thus a selection of the optimal tool for a specific project is often uncertain. This review aims to make recommendations to clinicians and researchers regarding practical, valid and reliable tools to assess upper quadrant posture and range of motion. Electronic databases and key journals were searched. A n adapted appraisal tool was utilised to assess the methodology for each of the nine selected articles. Nine eligible articles reporting on the goniometer, flexicurve and inclinometer were included. This review highlights the fact that a range of two-dimensional (2D) posture measurement tools are being used in clinical practice and research. A lthough the findings for the relia- bility and validity of the tools included in this review appear to be promising, strong recommendations are limited by the imprecision of the results. Thus, the primary issue hampering the recommendation for the most reliable and valid tool to use in the clinical or research setting is due to the limitations pertaining the analysis of the data, and the interpretation thereof. KEY W ORDS: RELIA BILITY, VA LIDITY, POSTURE, MEA SUREMENT TOOL A ND UPPER QUA DRA NT. Van Niekerk S, MSc Physiotherapy1; Louw Q, PhD1 1 Stellenbosch University information about the validity and relia- bility of postural measurement tools are limited. This might be due to practical implications of 2D posture measurement tools, poorly defined measurement procedures, and the inability to compare postural measurement tools to a “Gold Standard” to establish criterion validity. X-rays are regarded as the gold standard in postural evaluation, since they are a valid measure for determining the posi- tion of bony landmarks, which can then be used to calculate postural alignment (Harrison et al 2005). However, X-ray measurements are very costly; they are also impractical for large samples and may be inappropriate for young children (Harrison et al 2005). This review aims to make recommen- dations to clinicians and researchers regarding practical, valid and reliable tools to assess upper quadrant posture and range of motion. REVIEW METHODOLOGY The first objective of this paper is to describe inter-and intra-observer relia- bility of 2D posture and cervical range SA JOURNAL OF PHYSIOTHERAPY 2008 VOL 64 NO 3 13 of motion tools. The second objective is to assess the validity of common 2D posture measurement tools. Primary research reports published in the English language into validity and reliability of upper quadrant 2D posture and cervical range of motion in adults and adolescents without skeletal disease or serious pathology were considered for this review. 4.1 Search Strategy No date limits were applied to any of the databases. The researcher developed search strategies for Pubmed (since 1950), CINAHL (since 1982), The Cochrane Library (2006 Issue) Science Direct (since 1823) and Embase. The following key words present a summary of the important elements of the search strategy: reliability, validity, photo - graphy, digital image, photographic evaluation, photographic analysis, gonio- meter, inclinometer, electrogoniometer, flexicurve, posture and spine. No MESH headings were used. In addition, Pearling (searching refer- ence lists) was conducted to identify potential eligible articles from the refer- ence list of eligible articles. A citation search was also done in Pubmed for the authors who have published extensively in the field of posture and cervical range of motion measurement. The principle researcher and an assis- tant conducted all the searches and iden- tified eligible articles independently using the defined search strategies for each database. Both the researcher and assistant also independently identified eligible articles. Discrepancies in study selection were discussed till consensus was reached. 4.2 Methodological Appraisal Nine research articles were identified in the literature search. An adapted Crombie Appraisal Tool (CAT) for review studies was utilised to assess each of the selected articles (Crombie 1996). A review by Katrak et al. (2004) of critical appraisal instruments high- lighted the lack of a Gold Standard instrument, and encouraged reviewers to construct instruments that were relevant to their own review purpose (Katrak et al 2004). Questions in the CAT that were inappropriate of this critical appraisal were excluded. The open-ended ques- tions were rephrased in order to allow for dichotomous scoring. The researcher and assistant appraised the eligible publications independently. Any discrepancies were discussed until consensus was reached and a third party (the study supervisor) was consulted when required. The revised-version of the CAT contained the following questions: Figure.1: Database search method and results. 1. Goniometer (n = 3) 2. Inclinometer (n = 4) 3. Flexicurve (n =2) 4. Photography (n = 0) 5. Electrogoniometer (n = 0) • Pubmed (n = 83) • Cinahl (n = 48) • Embase (n = 232) • Sciencedirect (n = 28) • Cochrane (n = 9) • Author Search (n = 5) • Reference Search (n = 1) 406 Titles were screened by two independent reviewers 91 Abstracts were retrieved and read by two independent reviewers Excluded Articles (n = 315) Articles excluded based on the title that obviously did not conform to the aims of this review. Excluded (n = 22) The aim of the study was not to evaluate the reliability or validity of the measurement tool. Excluded Articles (n = 59) Research did not report on the reliability/ validity of 2D posture measurement tools when measuring cervical, shoulder or thoracic spine posture (n=58). Studies which did not use human subjects (n=1). 32 Full text articles retrieved and read by two independent reviewers Total of articles that form part of the review Total n = 9 14 SA JOURNAL OF PHYSIOTHERAPY 2008 VOL 64 NO 3 1. Is the subject of the study clearly stated? 2. Are the aims clearly stated? 3. Is the design appropriate to the stated aims? 4. Was the sample size justified? 5. Are the statistical measures described? 6. Do the numbers add up? 7. Were the basic data adequately described? 8. Is the meaning of the main findings explained? 9. Are factors that might have influenced the observed outcome, discussed? 10. Are important findings overlooked? 11. Is it stated how the results compare with previous reports? 12. Are the implications that the study has for your practice explored? 5. RESULTS 5.1 Selection of Studies and Evidence Level The findings of the search are presented in Figure 1. Nine eligible articles were included in the systematic review (Harrison et al 2005, Hinmann 2003/ 2004, Lee et al 2003, Malmstrˆm et al 2003, Pringle 2003, Tousignant et al 2001, Tousignant et al 2000, Youdas et al 1991, Moffet et al 1989). All nine research studies applied an observational design and are thus ranked as Level 3 on Sackett’s Evidence Hierarchy (Sackett et al 2000). 5.2 Methodological Appraisal Five of the nine articles scored 11 out of 12 on the revised CAT (Harrison et al 2005, Hinmann 2003/2004, Lee et al 2003, Pringle 2003, Tousignant et al 2000). Malstrom et al. (1989) scored 10 and Tousignant et al. (2000) and Youdas et al. (1991) scored 9 out of 12. Only one article scored a minimum of 8 on the revised CAT. * Sample size calculation Criterion 4 related to sample size cal - culation was only fulfilled in one of the studies reviewed (Tousignant et al 2000). Tousignant et al. (2001) compared their sample size of 44 subjects to the sample size of a study conducted by Donner and Eliasziw (1987) who stated that for an 80% power of testing and a 5% of significance, a minimum of 34 subjects is necessary (Donner and Eliasziw 1987). * Factors that might have influenced the observed outcome All nine of the reviewed studies obtained a positive answer to this cri - terion. This criterion was related to the factors that might have influenced the outcome of study. All of the studies considered discussed factors such as an appropriate design of the studies and standardised methodological procedures. * Description of basic data Moffet et al. (1989) is the only study that scored a negative response to this criterion as the study did not report on the age of the subjects used (Moffet et al 1989). 5.3 Study Characteristics In reference to Table 1, the sample size ranged from 26 to 96 and age (M: 47.7, SD: 22.3) ranged from 17 to 88 years old. Two of the studies reviewed used only female subjects while the other seven studies included males and females. None of the studies included adolescents or children. The earliest study was conducted in 1989 and the most recent in 2005. Fifty- five per cent of the studies were con- ducted in the United States of America and this may be reflective of research activity or publication bias. None of the published studies included Australian or African populations. 5.4 Study Aims The primary aim for each of the nine studies is described in Table 2. The three clinical measurement tools included were the goniometer, flexicurve and inclinometer. Five of the nine studies reported on inter and intra-tester reliability (see Table 2). One of the studies reported inter-tester reliability. The study by Malmstrˆm et al. (2003) is the only study reporting on measurement tool reliability (Malmström et al 2003). Concurrent validity was evaluated in three of the reviewed studies while only one study reported on criterion validity of the measurement tool. Harrison et al. (2005) and Lee et al. (2003) Tousignant et al. (2000) determined concurrent validity using X-rays as the gold standard. Harrison et al (2005) included Table 1: Study Characteristics Author Yr Sample Size Age range Total males Total females Moffet et al. 1989 26 Not stated 0 26 Youdas et al. 1991 60 21-48 21 39 Tousignant et al. 2000 31 18-45 10 21 Tousignant et al. 2001 44 18-73 25 20 Lee et al. 2003 35 18-35 20 15 Malmström et al. 2003 60 22-58 25 35 Pringle 2003 27 21-41 19 8 Hinmann 2003/ 2004 51 21-51 and 66-88 0 51 Harrison et al. 2005 96 Mean age: * Males 17.9 36 60 * Females 40.1 SA JOURNAL OF PHYSIOTHERAPY 2008 VOL 64 NO 3 15 Table 2: A summary of the procedures of the 2D posture measurement tools Study Measurement Reliability Primary Aim Static Angle Study Procedure Tool and Validity Measured Pringle 2003 Goniometer Concurrent To compare the tester Cervical flexion, Measurements were done validity reliability of the static extension, side flexion and three times with each of the cervical angle using four rotation position following four devices on different goniometers. the same day: * single hinge inclinometer * single bubble carpenter’s inclinometer * dual bubble goniometer * Cybex EDI 320 electrical inclinometer Position of subjects: Standing Youdas et al. 1991 Goniometer Inter and intra- To determine inter and Cervical flexion and All subjects were tested tester reliability intra-tester reliability extension position thrice in one day by three measuring static cervical different testers. angle. Position of subjects: Sitting Tousignant et al. 2000 Goniometer Concurrent To estimate the concurrent Cervical flexion, extension A lateral cervical X-ray was validity validity of the goniometer and side flexion position taken immediately after the with x-rays. measurements were done with the goniometer. Position of subjects: Sitting Tousignant et al. 2001 Inclinometer Inter and intra- To determine the inter- Cervical flexion and Two measurements were tester reliability and intra-tester reliability extension position taken by two trained testers. of the inclinometer. Position of subjects: Standing Lee et al. 2003 Inclinometer Inter and intra- To establish the inter- and Thoracic flexion, extension Two raters took single tester reliability intra-rater reliability and and side flexed position inclinometry measurements Concurrent validity of the inclinometer on two different days. The validity using thoracic X-rays. same angle was captured on x-rays and compared. Position of subjects: Standing Malmstrˆm et al. 2003 Inclinometer Measurement To estimate the measure - Cervical flexion and Recordings were made with tool reliability ment tool reliability, extension position the following inclinometers: Inter and intra- concurrent validity, • Zebris three- dimensional tester reliability inter-tester and, ultra-sound motion device Concurrent intra-tester reliability of • Myrin gravity-reference validity the inclinometer. goniometer, simultaneously Validity assessment Position of subjects: Standing using ultrasound. Moffet et al. 1989 Inclinometer Inter and intra- To determine the inter- Cervical flexion, extension, Neck angles were measured tester reliability and intra-tester reliability right and left side bending three times in one hour by of the inclinometer with and rotation position the same observer. static cervical angles. Neck angles were measured by two observers at the same time. Position of subjects: Standing Hinmann 2003/2004 Flexicurve Inter- tester To establish the inter-rater Thoracic kyphosis and Three graduate students reliability reliability of the flexicurve. lumbar lordosis. measured cervical lordosis and thoracic kyphosis in normal standing posture and then in an erect posture. Position of subjects: Standing Harrison et al. 2005 Flexicurve Concurrent To validate the flexicurve Cervical lordosis The flexicurve skin contour validity contour measurements and neutral lateral x-rays were of the cervical spine digitized and compared. lordosis with cervical Position of subjects: Standing X-rays. 16 SA JOURNAL OF PHYSIOTHERAPY 2008 VOL 64 NO 3 96 adult subjects and Lee et al. (2003) included 20 adult subjects (Harrison et al 2005, Lee et al 2003).The inclusion of only adults may be due to radiation expo- sure. The relatively small sample by Lee et al. (2003) may be due to the economic costs related to radiation exposure. One of the reviewed studies reported on subject variability (Malmström et al 2003). This is viewed to be a short - coming as it is an important element in estimating the standard error of measure- ment. This element should thus be con- sidered in future studies evaluating relia- bility of 2D posture measurement tools, particularly considering the indi vidual variability in posture (Christensen 1999). 5.5 Methodological Procedures Seven of the nine studies performed the measurements with the subjects in standing position, (Harrison et al 2005, Hinmann 2003/2004, Lee et al 2003, Malmstrˆm et al 2003, Pringle 2003, Tousignant et al 2000, Moffet et al 1989) while the other two studies tested the subjects in a seated position (Tousignant et al 2001, Youdas et al 1991). A variety of angles were measured in the studies reviewed. This included cervical flexion, extension, side flexion, left and right rotation static angles. Thoracic measurements included thoracic flexion, extension, side-flexion and rota - tion static angles. The studies were primarily conducted to evaluate elements of reliability and validity by measuring the static position after subjects were instructed to place their necks or tho- racic spines in a specific position such as flexion or extension. The only study which reported on the postural alignment of body segments is the study by Hinmann 2003/4. The researchers measured the position of lumbar lordosis and lumbar kyphosis. 5.6 Study Findings 5.6.1 Reliability Results The goniometer was found to be reliable in two studies (see Table 3) (Pringle 2003, Youdas 1991). The Inter-class Correlation Coefficients (ICC) values for the plastic hinge goniometer ranged between 0.89 for flexion and 0.97 for cervical side-flexion. The single goniometer scored ICC values of between 0.79 for cervical side flexion and 0.92 for flexion-extension combined. The dual bubble goniometer scored a minimum ICC value of 0.86 for the flexion-extension combination and a maximum of 0.94 for the side-flexed position. The cybex electric goniometer only assessed the static ROM for flexion- extension combination (ICC=0.89) and the side bending position was (ICC=0.75). Youdas et al. (1991) found the gonio - meter to be moderately reliable with ICC Table 3: Reliability of 2D posture measurement tools (ICC values). Pringle et al: Goniometer Youdas et al: Lee et al: Inclinometer (Cervical movements) Goniometer (Thoracic movements) (Cervical movements) Plastic Single Dual Cybex Intra- Inter- Intra- Intra- Inter- Inter- Hinge Bubble Rater Rater Rater: Rater 1 2 Day1 Day2 Right Side-Bending - - - - 0.85 0.72 0.84 0.84 0.45 0.46 Left Side-Bending - - - - 0.84 0.79 0.86 0.78 0.88 0.75 Flexion 0.96 - - - 0.83 0.57 0.84 0.88 0.81 0.85 Extension 0.96 - - - 0.86 0.79 0.79 0.48 0.65 0.86 Rotation Right - - - - 0.90 0.62 - - - - Rotation Left - - - - 0.78 0.54 - - - - Flexion-Extension Combined 0.96 0.97 0.95 0.96 - - - - - - Side-flexion Combined 0.98 0.92 0.93 0.90 - - - - - - Rotation Combined 0.99 0.96 0.97 - - - - - - - Table.4: Validity of 2D posture measurement tools Author Instrument Valid Malmstrom Inclinometer - Concurrent validity with ultrasound * ICC>0.93 for Cervical flexion and extension Lee Inclinometer Concurrent validity with x-rays *Left side thoracic position : ICC=0.43 * Right side thoracic position : ICC=0.44 Tousignant (2000) Goniometer - Concurrent validity with x-rays * Cervical extension r=0.97; Cervical flexion r=0.98 Harrison Flexicurve - Concurrent with x-rays * reliability coefficient < 0.15 for cervical lordosis SA JOURNAL OF PHYSIOTHERAPY 2008 VOL 64 NO 3 17 values ranging between 0.78 and 0.90 for the intra-tester reliability and 0.54 and 0.79 for the inter-tester reliability (see Table 3) (Youdas et al 1991). The reliability of the inclinometer was determined by four different studies. The first study found the inclinometer to have good inter-tester reliability (Malmstrˆm et al 2003). The second and third studies found it to have moderate reliability (see Table 3) (Tousignant et al 2000, Moffet et al 1989and the fourth (Lee et al 2003) (see Table 3) found it to be completely unreliable. Hinmann 2003/4 determined the inter-tester reliability of the flexicurve (Hinmann 2003/2004). For the kyphosis in relaxed posture, an ICC value of 0.94 was obtained and for the erect posture, 0.93. For the lordosis in relaxed posture, an ICC of 0.60 was obtained and for the erect posture, 0.73. 5.6.2 Validity Results Table 4 demonstrates the validity of the inclinometer, goniometer and flexicurve according to the study findings. The inclinometer was found to be valid in one study (Malmstrˆm et al 2003) and invalid in another (Lee et al 2003). The goniometer demonstrated excellent validity for what cervical movements (Tousignant et al 2001) whilst the flexicurve was found to be invalid for cervical lordosis measurement (Harrison et al 2005). 6. DISCUSSION This is the first attempt to review the reliability and validity of the goniometer, inclinometer and electrogoniometer when assessing the postural alignment of body segments of the upper quadrant. This review demonstrated that only one published study provides infor - mation on the validity of postural align- ment. Harrison et al (2005) assessed concurrent validity of the flexicurve comparing it to X-rays when measuring cervical lordosis in the standing position (Harrison et al 2005). There is thus a dearth of literature reporting on the vali - dity and reliability of “natural” postural alignment, despite the fact that posture is a predictor of musculoskeletal dys- function during sedentary activities such as sitting while using a computer (Vieira and Kumar 2004, National Institute for Occupational Safety and Health). Considering that posture is frequently assessed and rehabilitated by physio- therapists, further research in this field in required. Seven of the nine studies performed the measurements on subjects who were standing (Harrison et al 2005, Hinmann 2003/2004, Lee et al 2003, Malmström et al 2003, Pringle 2003, Tousignant et al 2000, Moffet et al 1989), and only two of the reviewed studies tested subjects in a sitting posture (Tousignant et al 2001, Youdas et al 1991). From this data, there appears to be an inadequate understanding of the reliability and validity of sitting posture measurement. This is worrisome to physiotherapists who would like to use these measures as most of our clients spend significant time in a seated position, either at school or at work, in a car or in front of the television (Granjean and Hunting 1977). Thus, it is proposed that further studies should be carried out where posture and movements are assessed, in all functional postures, to improve the clinical utility of the findings. The goniometer was the most studied instrument and the reliability results appear to be promising. Unfortunately, the methodological limitation in terms of sample size and statistical analysis does not allow us to strongly recom- mend the goniometer as a reliable tool. Firstly, although most of the studies appropriately applied the ICC, if the sample size is too small, the confidence intervals would be very wide (Jordan et al 2000). All, except one of the studies, calculated the sample size and only five of the reliability studies had a sample size of more than 30 subjects. It is a gen- eral guide that a sample size of at least 32 is required based on three repetitions or observers to give a power of more than 80%. Therefore, if no sample size calculation is provided it is crucial that confidence intervals are provided to allow for confidence in the study find- ings. In this review, none of the studies provided confidence intervals and therefore the degree of confidence in the findings is questionable. Concurrent validity was evaluated in three of the reviewed studies while one study reported on criterion validity of the measurement tool. Harrison et al. (2005) and Lee et al. (2003) determined concurrent validity using X-rays as the gold standard (Harrison et al 2005, Lee et al 2003). Normal X-rays pose a health threat to children and adolescents (Wall et al 2006). Children are considerably more sensitive to the carcinogenic effects of ionizing radiation than adults, and children have a longer life expectancy in which to express risk. The validity studies demonstrated similar shortcomings with respect to statistical analyses. None of the validity studies reported confidence intervals and therefore, it is not possible to ascer- tain whether these tools will be valid in a given population. Furthermore, all studies only used ICC’s which has limi- tations in providing insight to clinicians regarding the accuracy of the tool com- pared to the gold standard. ICC values are difficult to conceptualise as it is not in the unit of measurement and therefore does not provide clinicians with infor- mation on which they can base the selec- tion of a specific tool. It is thus recom- mended that Bland Altman plots should also be calculated as this gives the degree of accuracy in the specific measurement unit, such as degrees, and thereby allows much better understanding of the vali - dity of the tool. 7. CONCLUSION This review highlights that a range of 2D posture measurement tools are being used in clinical practice and research. Currently, the majority of the reviewed publications report on the reliability and validity of the goniometer. Although the findings for the reliability and validity of the tools included in this review appear to be promising, strong recom- mendations are limited by imprecision of the results. Thus, the primary issue hampering the recommendation for the most reliable and valid tool to use clini- cally or in a research setting is limita- tions pertaining to the data analysis and interpretation. 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