311
Journal of Back and Musculoskeletal Rehabilitation 28 (2015) 311–316 DOI 10.3233/BMR-140521 IOS Press
Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements by flexible curve Foad Seidia,∗ , Hooman Minoonejada and James W. Youdasb a
b
Department of Health and Sport Medicine, University of Tehran, Tehran, Iran Physical Therapy, Mayo Clinic, College of Medicine, Rochester, MN, USA
Abstract. BACKGROUND AND OBJECTIVE: The amount of postural sway and sagittal deviation of lumbar lordosis angle in measurements of standing lumbar curvature obtained by flexible curve can be decreased when using a spine stabilizer instrument. However, this assumption has not been investigated so far. This study aims to determine the effect of using a spine stabilizer instrument on the validity, reliability, and standard errors of measurement of flexible curve in the standing lumbar curvature measurements. MATERIAL AND METHOD: Thirty-four volunteer men aged between 19 and 30 years participated in the study By using a 50-cm flexible curve, with and without spine stabilizer instrument, and a lumbar simple lateral radiograph (LSLR), the standing lumbar curvature was measured by three methods for each subject. These methods were called A, B and C, respectively. RESULTS: By using the Pearson’s correlation analysis at significance level of 0.05, the coefficient of correlation between standing lumbar curvature measurements in methods A and B with C were 0.95 and 0.84, respectively. In addition, the intraclass correlation coefficient for methods A and B were 0.94 and 0.79, respectively. Also, results of the one-way analysis of variance for comparison of pairs indicated a significant difference in the mean values of standing lumbar curvature angles between methods B and C. CONCLUSIONS: Results indicated the flexible curve was an appropriate instrument for standing lumbar curvature measurements. Using spine stabilizer instrument to control postural sway increases the validity and reliability of flexible curve method and decreases its standard errors of measurement. Keywords: Spine stabilizer instrument, postural sway, standing lumbar curvature, flexible curve
1. Introduction Visual observation is a qualitative method most frequently used by clinicians for estimating the standing lumbar curvature (SLC) in sagittal plane. A variety of instruments can be used to obtain a quantitative surface assessment of the shape of the SLC [1]. It is important
∗ Corresponding author: Foad Seidi, Department of Health and Sport Medicine, University of Tehran, Kargare Shomali St, P.O.B: 1439813117, Tehran, Iran. Tel.: +98 216 111 8928; Fax: +98 218 822 5482; E-mail: [email protected].
to use valid, reliable, safe, portable and inexpensive instruments in any research pursuit [2]. Currently, the gold standard method for measuring the SLC is lumbar simple lateral radiograph (LSLR), but for such reasons as high costs and risks, particularly in extensive research and repeated measures, clinicians tend to use noninvasive devices including the flexible curve. The flexible curve was used in several studies for SLC measurements [1–14] and its validity and reliability have been reported to be high by several authors [3,15–18]. In fact, previous investigators reported the flexible curve was a suitable instrument in SLC
c 2015 – IOS Press and the authors. All rights reserved ISSN 1053-8127/15/$35.00
312
F. Seidi et al. / Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements Table 1 Descriptive statistics (Mean ± SD) of study (n = 34) Age (yrs) 23.75 ± 5.34
Height (cm) 179.45 ± 6.74
Weight (kg) 73.28 ± 7.16
BMI (Kg/m2 ) 22.11 ± 3.23
measurements. However, placing a flexible curve on the lumbar spine contour and applying pressure on it to copy the shape of the SLC can cause changes in the amount of postural sway and actual angle. Postural sway is the horizontal movement of the centre of gravity even when a person is standing still [19]. So, it manifests as random deflections of a body segment and may compromise maintenance of a standing posture [20,21]. It is an undesirable phenomenon for reliability of spinal shape examination because the spinal shape is depicted by a curve that is continuously changing. So, in repeated spinal shape examinations by a noninvasive method, reliable consistency cannot be achieved [22]. Random errors that reduce the reliability of spinal shape examination may be attributed to postural sway. Although many studies have used a flexible curve to measure the SLC, this issue has not been reported. Only Youdas et al. [1] in 2006 used a device to control postural sway while using the flexible curve. Nevertheless, the effectiveness of this device in reducing postural sway is not mentioned in that study. So, it is not clear whether the use of a spine stabilizer instrument (SSI) is effective in reducing the postural sway or not. Consequently, the purpose of this study was to investigate the effect of using a SSI on the validity, reliability and standard errors of measurement (SEM) of flexible curve in the SLC measurements.
SLC obtained by three methods (degree) A B C 40.88 ± 5.69 49.11 ± 5.75 43.31 ± 5.42
Fig. 1. The spine stabilizer instrument (SSI) and the manner of SLC measurement by the flexible curve. (Colours are visible in the online version of the article; http://dx.doi.org/10.3233/BMR-140521)
25; a history of fracture, surgery and/or arthritic diseases in spine and/or pelvis; neurological disease; severe pain in any body parts; and documented impairment of the vestibular system. Furthermore, those who had used medication with side-effects on the postural control system or unable to stand upright for about half an hour were excluded from the study.
2.3. Instrumentation 2. Methods 2.1. Participants Among patients referred to orthopedic clinic of University of Tehran to take LSLR, 34 males aged between 19 and 30 years voluntarily entered the study. The mean of age, weight and height of the subjects are shown in Table 1. 2.2. Inclusion and exclusion criteria The primary criteria for inclusion were men between 18 and 30 years old; willing and able to comply with the requirements defined in protocol for duration of study; and signed informed consent form. Also, exclusion criteria were BMI less than 18 and more than
SLC was measured with a flexible curve (50-cm long and 2-cm wide) that bends in one plane only and maintains a fixed shape, which can be transferred to paper with and without using a SSI, and a LSLR. The validity and reliability of flexible curve in SLC measurements was reported to be high [1,3]. SSI is a device designed and developed by researchers to control postural sway in SLC measurement process. This device is made of a platform, a central bar and two dowels; the central bar is located vertically in front of the platform and the dowels are horizontal in relation to the central bar (Fig. 1). The dowels are adjustable against the ground and in backward/forward directions and are in touch with the subject’s xiphoid process of the sternum and pubic symphysis while SLC measurement is obtained.
F. Seidi et al. / Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements
2.4. Procedure All subjects wore shorts so that the low back could be adequately exposed. Without shoes, body height (cm) and body mass (kg) of each subject was measured by a standard clinical scale (Continental Scale Corp., Bridgeview, IL). In this study, SLC was measured in three ways, including flexible curve with using a SSI (Method A), flexible curve without using a SSI (Method B) and LSLR (Method C). By placing small red adhesive dots on the skin corresponding to the spinous processes of T-12, L-4, and S-2, the SLC was captured with the flexible curve as described by Youdas, Suman, and Garrett in 1995 [18]. An examiner having 8 years of experience in using the flexible curve made all measurements. The spinous process of the S-2 vertebra was estimated by bisecting a straight line between the lower palpable borders of the subject’s posterior superior iliac spines. The spinous process of the L-4 vertebra was estimated by bisecting a straight line joining the highest palpable points of the subject’s iliac crests. The spinous process of the T-12 vertebra was estimated by identifying the inferior margins of ribs T-12 bilaterally and then simultaneously palpating these rib margins while moving superiorly and medially with the distal tips of each thumb until they disappeared deep into the soft tissue. At this point, the measurer estimated the location of spinous process T-12 by bisecting a straight line joining the tips of each thumb [18,23]. After the landmarks were marked, each subject stood barefoot on the base of the platform, taking a comfortable erect posture. Subjects were instructed to evenly distribute their body weight between their feet, looking at the opposite wall. To maintain the subject’s position for next trials, an outline of their feet was traced on a piece of paper [1]. Based on the pilot study, we observed that most subjects lost their relax posture after touching their body to find the bony landmarks. Therefore, the examiner waited for one minute so that the subject could reach the relax posture. Two horizontal dowels of the SSI were then positioned on an adjustable stand until touching the subject’s xiphoid process and pubic symphysis gently. This device was designed to control postural sway and only Youdas et al. [1] in 2006 used another kind of stabilizer in SLC measurement with one dowel. After the SSI was fixed, the flexible curve was molded to the midline contour of lumbosacral spine and the location of the red dots was represented by cable ties on the flexible curve (Fig. 1).
313
The flexible curve was carefully removed from the spine without changing its shape and placed on a piece of white poster board. The examiner maintained the shape of the flexible curve and an assistant depicted its outline on a piece of poster board. The sites corresponding to spinous processes of T-12, L-4 and S2 were also marked along the contour of the curve. Then, the subject stepped off the platform so that the examiner could remove red adhesive dots. The subject was asked to rest for one minute by walking around the study area, after which they stood on the platform by placing their feet on the traced outlines. The examiner palpated and marked the subject’s spinous processes with red adhesive dots for the second time. The measurements repeated again. In this second repetition, the lumbar curve was traced on the reverse side of the poster board. By doing so, the examiner would not be affected by its contour in calculating the first traced curvature [1]. Then, the examiner quantified the lumbar curvature in degrees using the technique described by Youdas et al. [1,4,18], which involves drawing three different straight lines on each tracing tangent to the marks previously made at the position of the spinous processes of T-12, L-4, and S-2. The intersections of these three tangent lines were measured with a clear plastic protractor marked in 1-degree units. The sum of the two angles was the estimate of the SLC. The procedure was repeated once more without using the SSI (Method B) to compare these different methods of SLC measurement (A and B) with LSLR (Method C) as gold standard method. LSLR was taken in a relaxed posture with the subjects’ left side toward the film cassette and hands placed on a height-adjustable bar so the arms were flexed at 30 degrees from the shoulder [2]. Then, SLC angle was measured with the modified Cobb’s angle method, based on the technique originally described by Cobb [24] to quantify scoliosis. Finally, methods A and B were repeated once more the next day to identify intra-tester reliability of flexible curve in SLC measurements. 2.5. Statistical analysis The raw data obtained from measurements of variables of this study were analyzed by using SPSS for Windows, ver. 18.0, and descriptive and inferential statistics. A Pearson’s correlation analysis was used to assign the validity of SLC measurements obtained by methods A and B. Also, a one-way analysis of variance and a Bland-Altman comparison [25–28] were used to examine the differences between mean values of SLC
314
F. Seidi et al. / Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements
Fig. 2. Differences (degrees) between A and C methods of the SLC (n = 34).
Fig. 4. Differences (degrees) between A and B methods of the SLC (n = 34).
ferent methods (F = 7.46; p = 0.001; df = 2). Bonferroni Test for comparison of pairs indicated a statistically significant difference in the mean values of SLC angles between method B and methods A (p = 0.001) and C (p = 0.017). Figures 2–4 display the plots of the algebraic differences (y-axis) vs. the mean value (x-axis) for each of the SLC, as measured by the three methods.
4. Discussion
Fig. 3. Differences (degrees) between B and C methods of the SLC (n = 34).
obtained by methods A, B and C. In addition, the intraclass correlation coefficient (ICC1,2 ) and SEM were used to characterize intra-tester reliability of the flexible curve in methods A and B [29]. Significance level was considered to be 95%, with alpha being 0.05.
3. Results Descriptive statistics were provided for 34 subjects (Table 1). The coefficient of correlation in SLC measurements between methods A and B with method C were 0.95 and 0.84, respectively. In addition, the ICCs for methods A and B were 0.94 and 0.79 and the SEM for these methods were 1.39 and 2.63, respectively. Also, the results obtained from one-way analysis of variance indicated there was significant difference between the mean values of SLC angles measured by dif-
According to the findings of the present study, applying a flexible curve in SLC measurements with and without using SSI (Methods A and B) has a high correlation with LSLR (Method C). These findings are in agreement with the results of previous studies [3,15, 16]. It could be concluded that there is high validity in SLC measurement by applying a flexible curve with methods A and B. However, the validity of method A (r = 0.95) is significantly higher than method B (r = 0.84). The same conclusions could also be reached regarding the reliability of the flexible curve. Hart and Rose [15], Walker et al. [17], Youdas et al. [18], Nourbakhsh and Moussavi [16], and Seidi et al. [3] reported ICC quantities for intra-tester reliability of the flexible curve as 0.97, 0.97, 0.87, 0.88, and 0.92, respectively. In 2004, Mannion et al. [30] reported four levels for ICC values based on Currier [31]: 0.90–0.99 = high reliability, 0.80–0.89 = good reliability, 0.70–0.79 = fair reliability,
Journal of Back and Musculoskeletal Rehabilitation 28 (2015) 311–316 DOI 10.3233/BMR-140521 IOS Press
Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements by flexible curve Foad Seidia,∗ , Hooman Minoonejada and James W. Youdasb a
b
Department of Health and Sport Medicine, University of Tehran, Tehran, Iran Physical Therapy, Mayo Clinic, College of Medicine, Rochester, MN, USA
Abstract. BACKGROUND AND OBJECTIVE: The amount of postural sway and sagittal deviation of lumbar lordosis angle in measurements of standing lumbar curvature obtained by flexible curve can be decreased when using a spine stabilizer instrument. However, this assumption has not been investigated so far. This study aims to determine the effect of using a spine stabilizer instrument on the validity, reliability, and standard errors of measurement of flexible curve in the standing lumbar curvature measurements. MATERIAL AND METHOD: Thirty-four volunteer men aged between 19 and 30 years participated in the study By using a 50-cm flexible curve, with and without spine stabilizer instrument, and a lumbar simple lateral radiograph (LSLR), the standing lumbar curvature was measured by three methods for each subject. These methods were called A, B and C, respectively. RESULTS: By using the Pearson’s correlation analysis at significance level of 0.05, the coefficient of correlation between standing lumbar curvature measurements in methods A and B with C were 0.95 and 0.84, respectively. In addition, the intraclass correlation coefficient for methods A and B were 0.94 and 0.79, respectively. Also, results of the one-way analysis of variance for comparison of pairs indicated a significant difference in the mean values of standing lumbar curvature angles between methods B and C. CONCLUSIONS: Results indicated the flexible curve was an appropriate instrument for standing lumbar curvature measurements. Using spine stabilizer instrument to control postural sway increases the validity and reliability of flexible curve method and decreases its standard errors of measurement. Keywords: Spine stabilizer instrument, postural sway, standing lumbar curvature, flexible curve
1. Introduction Visual observation is a qualitative method most frequently used by clinicians for estimating the standing lumbar curvature (SLC) in sagittal plane. A variety of instruments can be used to obtain a quantitative surface assessment of the shape of the SLC [1]. It is important
∗ Corresponding author: Foad Seidi, Department of Health and Sport Medicine, University of Tehran, Kargare Shomali St, P.O.B: 1439813117, Tehran, Iran. Tel.: +98 216 111 8928; Fax: +98 218 822 5482; E-mail: [email protected].
to use valid, reliable, safe, portable and inexpensive instruments in any research pursuit [2]. Currently, the gold standard method for measuring the SLC is lumbar simple lateral radiograph (LSLR), but for such reasons as high costs and risks, particularly in extensive research and repeated measures, clinicians tend to use noninvasive devices including the flexible curve. The flexible curve was used in several studies for SLC measurements [1–14] and its validity and reliability have been reported to be high by several authors [3,15–18]. In fact, previous investigators reported the flexible curve was a suitable instrument in SLC
c 2015 – IOS Press and the authors. All rights reserved ISSN 1053-8127/15/$35.00
312
F. Seidi et al. / Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements Table 1 Descriptive statistics (Mean ± SD) of study (n = 34) Age (yrs) 23.75 ± 5.34
Height (cm) 179.45 ± 6.74
Weight (kg) 73.28 ± 7.16
BMI (Kg/m2 ) 22.11 ± 3.23
measurements. However, placing a flexible curve on the lumbar spine contour and applying pressure on it to copy the shape of the SLC can cause changes in the amount of postural sway and actual angle. Postural sway is the horizontal movement of the centre of gravity even when a person is standing still [19]. So, it manifests as random deflections of a body segment and may compromise maintenance of a standing posture [20,21]. It is an undesirable phenomenon for reliability of spinal shape examination because the spinal shape is depicted by a curve that is continuously changing. So, in repeated spinal shape examinations by a noninvasive method, reliable consistency cannot be achieved [22]. Random errors that reduce the reliability of spinal shape examination may be attributed to postural sway. Although many studies have used a flexible curve to measure the SLC, this issue has not been reported. Only Youdas et al. [1] in 2006 used a device to control postural sway while using the flexible curve. Nevertheless, the effectiveness of this device in reducing postural sway is not mentioned in that study. So, it is not clear whether the use of a spine stabilizer instrument (SSI) is effective in reducing the postural sway or not. Consequently, the purpose of this study was to investigate the effect of using a SSI on the validity, reliability and standard errors of measurement (SEM) of flexible curve in the SLC measurements.
SLC obtained by three methods (degree) A B C 40.88 ± 5.69 49.11 ± 5.75 43.31 ± 5.42
Fig. 1. The spine stabilizer instrument (SSI) and the manner of SLC measurement by the flexible curve. (Colours are visible in the online version of the article; http://dx.doi.org/10.3233/BMR-140521)
25; a history of fracture, surgery and/or arthritic diseases in spine and/or pelvis; neurological disease; severe pain in any body parts; and documented impairment of the vestibular system. Furthermore, those who had used medication with side-effects on the postural control system or unable to stand upright for about half an hour were excluded from the study.
2.3. Instrumentation 2. Methods 2.1. Participants Among patients referred to orthopedic clinic of University of Tehran to take LSLR, 34 males aged between 19 and 30 years voluntarily entered the study. The mean of age, weight and height of the subjects are shown in Table 1. 2.2. Inclusion and exclusion criteria The primary criteria for inclusion were men between 18 and 30 years old; willing and able to comply with the requirements defined in protocol for duration of study; and signed informed consent form. Also, exclusion criteria were BMI less than 18 and more than
SLC was measured with a flexible curve (50-cm long and 2-cm wide) that bends in one plane only and maintains a fixed shape, which can be transferred to paper with and without using a SSI, and a LSLR. The validity and reliability of flexible curve in SLC measurements was reported to be high [1,3]. SSI is a device designed and developed by researchers to control postural sway in SLC measurement process. This device is made of a platform, a central bar and two dowels; the central bar is located vertically in front of the platform and the dowels are horizontal in relation to the central bar (Fig. 1). The dowels are adjustable against the ground and in backward/forward directions and are in touch with the subject’s xiphoid process of the sternum and pubic symphysis while SLC measurement is obtained.
F. Seidi et al. / Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements
2.4. Procedure All subjects wore shorts so that the low back could be adequately exposed. Without shoes, body height (cm) and body mass (kg) of each subject was measured by a standard clinical scale (Continental Scale Corp., Bridgeview, IL). In this study, SLC was measured in three ways, including flexible curve with using a SSI (Method A), flexible curve without using a SSI (Method B) and LSLR (Method C). By placing small red adhesive dots on the skin corresponding to the spinous processes of T-12, L-4, and S-2, the SLC was captured with the flexible curve as described by Youdas, Suman, and Garrett in 1995 [18]. An examiner having 8 years of experience in using the flexible curve made all measurements. The spinous process of the S-2 vertebra was estimated by bisecting a straight line between the lower palpable borders of the subject’s posterior superior iliac spines. The spinous process of the L-4 vertebra was estimated by bisecting a straight line joining the highest palpable points of the subject’s iliac crests. The spinous process of the T-12 vertebra was estimated by identifying the inferior margins of ribs T-12 bilaterally and then simultaneously palpating these rib margins while moving superiorly and medially with the distal tips of each thumb until they disappeared deep into the soft tissue. At this point, the measurer estimated the location of spinous process T-12 by bisecting a straight line joining the tips of each thumb [18,23]. After the landmarks were marked, each subject stood barefoot on the base of the platform, taking a comfortable erect posture. Subjects were instructed to evenly distribute their body weight between their feet, looking at the opposite wall. To maintain the subject’s position for next trials, an outline of their feet was traced on a piece of paper [1]. Based on the pilot study, we observed that most subjects lost their relax posture after touching their body to find the bony landmarks. Therefore, the examiner waited for one minute so that the subject could reach the relax posture. Two horizontal dowels of the SSI were then positioned on an adjustable stand until touching the subject’s xiphoid process and pubic symphysis gently. This device was designed to control postural sway and only Youdas et al. [1] in 2006 used another kind of stabilizer in SLC measurement with one dowel. After the SSI was fixed, the flexible curve was molded to the midline contour of lumbosacral spine and the location of the red dots was represented by cable ties on the flexible curve (Fig. 1).
313
The flexible curve was carefully removed from the spine without changing its shape and placed on a piece of white poster board. The examiner maintained the shape of the flexible curve and an assistant depicted its outline on a piece of poster board. The sites corresponding to spinous processes of T-12, L-4 and S2 were also marked along the contour of the curve. Then, the subject stepped off the platform so that the examiner could remove red adhesive dots. The subject was asked to rest for one minute by walking around the study area, after which they stood on the platform by placing their feet on the traced outlines. The examiner palpated and marked the subject’s spinous processes with red adhesive dots for the second time. The measurements repeated again. In this second repetition, the lumbar curve was traced on the reverse side of the poster board. By doing so, the examiner would not be affected by its contour in calculating the first traced curvature [1]. Then, the examiner quantified the lumbar curvature in degrees using the technique described by Youdas et al. [1,4,18], which involves drawing three different straight lines on each tracing tangent to the marks previously made at the position of the spinous processes of T-12, L-4, and S-2. The intersections of these three tangent lines were measured with a clear plastic protractor marked in 1-degree units. The sum of the two angles was the estimate of the SLC. The procedure was repeated once more without using the SSI (Method B) to compare these different methods of SLC measurement (A and B) with LSLR (Method C) as gold standard method. LSLR was taken in a relaxed posture with the subjects’ left side toward the film cassette and hands placed on a height-adjustable bar so the arms were flexed at 30 degrees from the shoulder [2]. Then, SLC angle was measured with the modified Cobb’s angle method, based on the technique originally described by Cobb [24] to quantify scoliosis. Finally, methods A and B were repeated once more the next day to identify intra-tester reliability of flexible curve in SLC measurements. 2.5. Statistical analysis The raw data obtained from measurements of variables of this study were analyzed by using SPSS for Windows, ver. 18.0, and descriptive and inferential statistics. A Pearson’s correlation analysis was used to assign the validity of SLC measurements obtained by methods A and B. Also, a one-way analysis of variance and a Bland-Altman comparison [25–28] were used to examine the differences between mean values of SLC
314
F. Seidi et al. / Using a spine stabilizer instrument to control postural sway in standing lumbar curvature measurements
Fig. 2. Differences (degrees) between A and C methods of the SLC (n = 34).
Fig. 4. Differences (degrees) between A and B methods of the SLC (n = 34).
ferent methods (F = 7.46; p = 0.001; df = 2). Bonferroni Test for comparison of pairs indicated a statistically significant difference in the mean values of SLC angles between method B and methods A (p = 0.001) and C (p = 0.017). Figures 2–4 display the plots of the algebraic differences (y-axis) vs. the mean value (x-axis) for each of the SLC, as measured by the three methods.
4. Discussion
Fig. 3. Differences (degrees) between B and C methods of the SLC (n = 34).
obtained by methods A, B and C. In addition, the intraclass correlation coefficient (ICC1,2 ) and SEM were used to characterize intra-tester reliability of the flexible curve in methods A and B [29]. Significance level was considered to be 95%, with alpha being 0.05.
3. Results Descriptive statistics were provided for 34 subjects (Table 1). The coefficient of correlation in SLC measurements between methods A and B with method C were 0.95 and 0.84, respectively. In addition, the ICCs for methods A and B were 0.94 and 0.79 and the SEM for these methods were 1.39 and 2.63, respectively. Also, the results obtained from one-way analysis of variance indicated there was significant difference between the mean values of SLC angles measured by dif-
According to the findings of the present study, applying a flexible curve in SLC measurements with and without using SSI (Methods A and B) has a high correlation with LSLR (Method C). These findings are in agreement with the results of previous studies [3,15, 16]. It could be concluded that there is high validity in SLC measurement by applying a flexible curve with methods A and B. However, the validity of method A (r = 0.95) is significantly higher than method B (r = 0.84). The same conclusions could also be reached regarding the reliability of the flexible curve. Hart and Rose [15], Walker et al. [17], Youdas et al. [18], Nourbakhsh and Moussavi [16], and Seidi et al. [3] reported ICC quantities for intra-tester reliability of the flexible curve as 0.97, 0.97, 0.87, 0.88, and 0.92, respectively. In 2004, Mannion et al. [30] reported four levels for ICC values based on Currier [31]: 0.90–0.99 = high reliability, 0.80–0.89 = good reliability, 0.70–0.79 = fair reliability,
