Reliability and concurrent validity of the Metrecom for length measurements on inanimate objects.A number of methods for assessing various aspects of human posture have been developed.[1-10] One of the newer systems designed for posture analysis, the Metrecom,* is a computerized, electromechanical The use of electricity to run moving parts. Disk drives, printers and motors are examples. Electromechanical systems must be designed for the eventual deterioration of moving components that wear over time. The first TVs were electromechanical systems (see video/TV history). , three-dimensional (3-D) digitizer dig·i·tize tr.v. dig·i·tized, dig·i·tiz·ing, dig·i·tiz·es To put (data, for example) into digital form. dig . Before this new system is considered for use in the clinical setting, the ability to obtain reliable measurements should be demonstrated. We know of only one study" designed to assess the reliability of Metrecom-obtained measurements that has been published in a source other than the proceedings of a conference. in that report, Hoyle et al[11] discussed the reliability and concurrent validity concurrent validity, n the degree to which results from one test agree with results from other, different tests. (term not used by authors) of the Metrecom for measuring leg length, but they did not indicate which of the Metrecom's testing modes they used nor did they examine the results of two different testing modes for comparability. We tested the reliability of the Metrecom for measuring lengths with two different testing modes and the concurrent validity of measurements obtained by use of the two Metrecom testing modes, both with each other and with measurements obtained with a tape measure. Methods Data Sources The sources of data (subjects) for this study were pairs of points, each of which defined a length to be measured, marked on the surfaces of five different inanimate objects Inanimate Objects abiology the study of inanimate things. animatism the assignment to inanimate objects, forces, and plants of personalities and wills, but not souls. — animatistic, adj. . Our rationale for using inanimate objects was to ensure stability of the data sources. The reasons for selecting specific objects and the methods for selecting the locations of points on each of the objects varied. The rationale for using the first data source, labeled "BOX" (Fig. 1), was that it provided a stable data source for pairs of points in each of three orthogonal At right angles. The term is used to describe electronic signals that appear at 90 degree angles to each other. It is also widely used to describe conditions that are contradictory, or opposite, rather than in parallel or in sync with each other. planes. The criteria for selection of points for the BOX were to place pairs of points within each of three planes and to select a range of lengths (distances between points). The BOX, which measured 38 x 30 x 10 cm and was secured with an adhesive compound to the top, of a table, had 20 pairs of points placed pseudorandomly (ie, points were not chosen systematically, but a specific randomization randomization (ranˈ·d  ·m procedure was not
used) on three adjacent surfaces. Although points were located on each
of three orthogonal surfaces, both members of a pair of points were
located on the same surface. For ease of viewing, only a subset of the
pairs of points are depicted in the schematic A graphical representation of a system. It often refers to electronic circuits on a printed circuit board or in an integrated circuit (chip). See logic gate and HDL. (Fig. 1).The second data source, labeled "CORNER" (Fig. 2), was selected to permit measurement both of longer distances and of lengths defined by points in two different planes. The CORNER data source consisted of 30 pairs of points marked on the surfaces of two adjacent walls and on the floor between the two walls. Points for the CORNER were selected randomly. The range of possible lengths was prescribed as 1 to 3,000 mm because the digitization dig·i·tize tr.v. dig·i·tized, dig·i·tiz·ing, dig·i·tiz·es To put (data, for example) into digital form. dig arm of the Metrecom cannot reach points beyond 1,500 mm in any direction. Then a table of random numbers was used to establish the prescribed distances between points in a pair (excluding numbers in the random series that fell outside the prescribed range). Finally, the plane on which each point was to be placed was selected by a process of random selection without replacement. Note that for some pairs of points, in contrast to the case for the BOX, the individual members of the pair were on different surfaces (Fig. 2). The third data source, labeled "SKELETON" (Fig. 3), was a human skeleton The human skeleton consists of both fused and individual bones supported and supplemented by ligaments, tendons, muscles and cartilage. Fused bones include those of the pelvis and the cranium. Osteocytes are present in the bone matrix. that was suspended in an upright, anatomical position anatomical position n. The erect position of the body with the face directed forward, the arms at the side, and the palms of the hands facing forward, used as a reference in describing the relation of body parts to one another. with the feet taped to the floor to limit swaying. This data source was used to approximate more closely the manufacturer's intended clinical use of the Metrecom and yet ensure stability of the data source. Points for the SKELETON were 28 bony landmarks selected to permit measurement of the distances between the resulting 14 pairs of landmarks, for example, the greater trochanter greater trochanter n. A strong process overhanging the root of the neck of the femur, giving attachment to the gluteus medius and minimus muscles, the piriform muscle, the internal and external obturator muscles, and the gemelli muscles. to the lateral malleolus The lower extremity (distal extremity; external malleolus) of the fibula is of a pyramidal form, and somewhat flattened from side to side; it descends to a lower level than the medial malleolus. and the anterior superior iliac spine The anterior superior iliac spine (ASIS) is an important landmark of surface anatomy. It refers to the anterior extremity of the iliac crest of the pelvis, which provides attachment for the inguinal ligament and the sartorius muscle. to the medial malleolus The medial surface of the lower extremity of tibia is prolonged downward to form a strong pyramidal process, flattened from without inward - the medial malleolus.
Data from the fourth data source, identified as "CURVES," was used to simulate data that potentially could be used to describe the shape of a human subject's spine. The data source was 88 points placed on the surface of five flexible rulers, each of which had been shaped into a different two-bend (cubic-fit) curve. Points for the CURVES (Fig. 4) were chosen systematically as follows. The flexible rulers were taped to a piece of Masonite[dagger] (75x75 cm) to prevent distortion of the curves between measurements. Marks were placed every 2.54 cm along the top edge of the piece of Masonite parallel to the long axes of the flexible rulers. A carpenter's square with one arm aligned parallel to the top edge of the piece of Masonite and the other arm extending across the flexible rulers was placed successively at each of the marks along the top edge of the piece of Masonite. Then the second point of each pair was placed on each of the flexible rulers at the point where the carpenter's square passed over the flexible ruler. Thus, a pair of points consisted of a point on the top edge of the piece of Masonite and the similarly numbered point on a flexible ruler. For clarity, only the schematic of the middle flexible ruler (curve) is labeled with pair numbers in Figure 4. Note, however, that each point on the other flexible rulers curves) was numbered correspondingly and served as the second member of a pair of points with the similarly numbered point on the top edge of the piece of Masonite. Data from the fifth data source, referred to as "PAPER" (Fig. 5), was used to test the ability of the measurement system to discriminate among relatively short (<50 mm) lengths. The data source set consisted of 20 pairs of points marked on a piece of paper. A set of lengths for PAPER Fig. 5) were selected randomly using a table of random numbers. The maximum length for this set was 50 mm. Pairs of points were placed the specified distances apart on a piece of paper using a ruler. The orientation of the ruler on the paper was determined by rotating the paper blindly and then dropping the ruler on the paper. Descriptive statistics descriptive statistics see statistics. for the data sources are provided in Table 1. Note that for each object, a number of different lengths were measured (as indicated by the column labeled "n"). The values listed in Table 1 are larger than the number of pairs of points shown in the schematics because not all points are represented on the schematics (Figs. 1, 2, 4, and 5). The values for shortest length, longest length, mean, and standard deviation In statistics, the average amount a number varies from the average number in a series of numbers. (statistics) standard deviation - (SD) A measure of the range of values in a set of numbers. are descriptive of the set of lengths used for each object.
Table 1. Descriptive Statistics for Data Sources
[Length.sup.a]
Data _____________________________________
Source [n.sup.b] [S.sup.c] [L.sup.d] X SD
BOX 20 2.7 30.8 13.46 8.57
CORNER 30 1.9 180.8 70.53 52.21
SKELETON 14 14.5 76.7 39.32 23.80
CURVES 88 6.0 45.2 21.60 12.10
PAPER 20 0.2 5.0 2.33 1.51
(a) Values for length are derived from measurements taken with the tape measure
(or ruler) and are
expressed in centimeters.
([n.sup.b]) = number of pairs of points yielding lengths.
([S.sup.c] = shortest length measured on object.
([L.sup.d]) = longest length measured on object.
Apparatus The Metrecom is an electromechanical, 3-D digitizer interfaced to a Compaq portable The Compaq Portable was the first product in the Compaq portable series to be brought out by Compaq Computer Corporation. It was the first "100%" IBM PC compatible personal computer not manufactured by IBM, and also the first IBM PC compatible portable computer. microcomputer. The Compaq[double dagger double dagger n. A reference mark (  ) used in printing and writing. Also called diesis.Noun 1. ] portable microcomputer, Model 101709, is an IBM-PC IBM-PC International Business Machines Corporation Personal Computer type containing an Intel[sections] 8088 microprocessor chip running at 4.77 MHz (MegaHertZ) One million cycles per second. It is used to measure the transmission speed of electronic devices, including channels, buses and the computer's internal clock. A one-megahertz clock (1 MHz) means some number of bits (16, 32, 64, etc. , with 256 Kb of random access memory and a built-in monochrome monitor Monochrome monitors are a type of computer display which were very common in the early days of computing, from the 1960s through the 1980s, before the advent of color monitors. They are still used today in some computerized cash register systems, amongst other select applications. . According to according to prep. 1. As stated or indicated by; on the authority of: according to historians. 2. In keeping with: according to instructions. 3. the Metrecom manufacturer's Technical Specification Sheet, The Metrecom accuracy is measured according to the ASME ASME - American Society of Mechanical Engineers ANSI (American National Standards Institute, New York, www.ansi.org) A membership organization founded in 1918 that coordinates the development of U.S. voluntary national standards in both the private and public sectors. It is the U.S. member body to ISO and IEC. B89.1.12 standard for 3-dimensional coordinate measurement machines. FARO reports the accuracy of the Metrecom as [+ or -] 1/2 the maximum error bandwidth. The Metrecom has an accuracy of [+ or -]O.25 within its working volume .... The Metrecom's measurement assembly consists of a six-degree-of-freedom mechanical linkage instrumented with a factory-calibrated, proprietary, analog/digital hybrid rotational transducer transducer, device that accepts an input of energy in one form and produces an output of energy in some other form, with a known, fixed relationship between the input and output. at each of the six joints. The measurement assembly is secured to a vertical support column. The tranducers are connected to a proprietary interface card in the microcomputer. In using the Metrecom, the terminal link of the assembly is moved by the tester to any point within the range of the linkage (approximately 1.5 m in all directions). When a point to be digitized is in contact with the tip of the terminal link, a switch is depressed and a signal representing the position of each transducer is sent to the microcomputer. The microcomputer converts the signal into x, y, and z coordinates, and, depending on the specific mode of operation, the microcomputer calculates the values of variables such as line lengths. The software for the Metrecom (Version 2.00) is menu-driven. The testing in this study involved only three of the menu options: 3-D Digitizer (3DD), Line Length (LL), and 3-D Digitizer Diagnosis. In the 3DD mode, the user may move the terminal link of the electromechanical linkage assembly to any point in the Metrecom's working space, depress de·press v. 1. To lower in spirits; deject. 2. To cause to drop or sink; lower. 3. To press down. 4. To lessen the activity or force of something. the switch, and obtain the x, y, and z coordinates of the point. Points digitized by the user are displayed on the computer screen in the context of a coordinate system coordinate system Arrangement of reference lines or curves used to identify the location of points in space. In two dimensions, the most common system is the Cartesian (after René Descartes) system. . In addition, the x, y, and z coordinates of the points can be transmitted to the printer and stored in an ASCII file A file that contains data made up of ASCII characters. It is essentially raw text just like the words you are reading now. Each byte in the file contains one character that conforms to the standard ASCII code (see ASCII chart). for subsequent data processing data processing or information processing, operations (e.g., handling, merging, sorting, and computing) performed upon data in accordance with strictly defined procedures, such as recording and summarizing the financial transactions of a . The LL mode of operation was designed to permit measurements of lengths on patients. Once the LL mode is initialized, the computer prompts the user by voice command to digitize To convert an image or signal into digital code by scanning, tracing on a graphics tablet or using an analog to digital conversion device. 3D objects can be digitized by a device with a mechanical arm that is moved onto all the corners. each point in each position. When the points have been digitized, the computer calculates the straightline distance between the points and transmits the result to the printer. The 3-D Digitizer Diagnosis mode of operation enables the user to verify whether the system meets the factory specified calibration standards. The calibration verification consists of digitizing "Digitizer" redirects here. For the computer device, see Digitizing tablet. For the digitizer in Tablet PC's, see Tablet PC. Digitizing or digitization three specified points on the base of the Metrecom in response to voice commands from the system's computer. The system then either displays a set of calibration indexes or, if data are unacceptable, a message to contact the manufacturer. Neither the range of acceptable indexes nor the meaning of the indexes is described in the system manual. Study Design The design of the study was based on a test-retest format. Both intratester and intertester reliability were assessed for each of two Metrecom testing modes (3DD and LL) on each of three inanimate objects (BOX, CORNER, SKELETON). On the fourth object (CURVES), both intratester and intertester reliability were assessed for only the 3DD mode. Intratester reliability with the 3DD mode only was assessed for the fifth object (PAPER). Procedures Prior to the start of testing, the Metrecom was positioned in proximity to the object, the base of the Metrecom was leveled, the calibration of the system was verified, and the appropriate menu item was selected on the system's computer. All points on the data source object were marked either with adhesive markers (CORNER, SKELETON, and CURVES) or with a pencil (BOX and PAPER). The markers remained in place for the duration of testing for the object. Points were digitized by placing the tip of the terminal link of the Metrecom in contact with a mark and depressing the switch. For BOX., CORNER, and SKELETON, each of two testers digitized each point twice in each of two modes of testing (3DD and LL); for CURVES, only the 3DD mode was used; and for PAPER, only one tester and one mode (3DD) were used. For testing of BOX and CURVES, testers alternated only after digitizing the complete set of points. In testing of CORNER and SKELETON, for purposes of comparison between techniques, testers alternated after each pair of points on one trial but after the entire set on the other trial in each mode. All testing of the BOX and PAPER data sources occurred within single sessions. Testing of each of the other sets of points was conducted on two separate days (two different days for each set). The interval between test sessions was 3 days. Testing was conducted at approximately the same time of day for all sets. Lengths referred to as "actual" were obtained with a tape measure or ruler. Lengths derived from the 3DD data were calculated using the Pythagorean theorem Pythagorean theorem Rule relating the lengths of the sides of a right triangle. It says that the sum of the squares of the lengths of the legs is equal to the square of the length of the hypotenuse (the side opposite the right angle). to determine the distance between each pair of points. Data Analysis The intraclass correlation In statistics, the intraclass correlation (or the intraclass correlation coefficient[1]) is a measure of correlation, consistency or conformity for a data set when it has multiple groups. coefficient (ICC ICC See: International Chamber of Commerce ) in conjunction with a one-way analysis of variance (ANOVA anova see analysis of variance. ANOVA Analysis of variance, see there ) for repeated measures was used to assess reliability of the two sets of length measurements obtained with the Metrecom. Based on study design and expectations for generalizability,[12] a random-effects model of the ICC (2,1) was used to assess intertester reliability, and a fixed-effects model ICC (3,1) was used to test intratester reliability. In addition, an F ratio from the repeated-measures ANOVA was used to assess the significance of differences between repeated measures ([F.sub.Testers]). The F ratios were used as aids in the interpretation of the ICC because the ICC is more sensitive to random error than to systematic error. Thus, even though the ICC may be at an acceptable level, there may be significant differences between repeated measures. An optimal set of results would include a value of the ICC close to 1.00 and a nonsignificant non·sig·nif·i·cant adj. 1. Not significant. 2. Having, producing, or being a value obtained from a statistical test that lies within the limits for being of random occurrence. [F.sub.Testers] value. The following specific comparisons were made to assess reliability for each mode of testing (3DD and LL): (1) intratester: tester 1, measure 1 versus tester 1, measure 2 and tester 2, measure 1 versus tester 2, measure 2 and (2) intertester: tester 1, measure 1 versus tester 2, measure 1 and tester 1, measure 2 versus tester 2, measure 2. The Pearson Product-moment Correlation Coefficient Noun 1. Pearson product-moment correlation coefficient - the most commonly used method of computing a correlation coefficient between variables that are linearly related product-moment correlation coefficient (r) in combination with the repeated-measures t test was used to assess concurrent validity of the two Metrecom measures of length, both with each other and with those of the tape measure (or ruler). The Pearson correlation coefficient Correlation Coefficient A measure that determines the degree to which two variable's movements are associated. The correlation coefficient is calculated as: was used to quantify covariation Noun 1. covariation - (statistics) correlated variation statistics - a branch of applied mathematics concerned with the collection and interpretation of quantitative data and the use of probability theory to estimate population parameters , and the t test was used to test for systematic differences between the measures. The following specific comparisons were made to assess concurrent validity: (1) actual lengths versus LLs, (2) actual lengths versus 3DD-derived lengths, and (3) 3DD-derived lengths and LLs. Results The means of the data used for the reliability and validity analyses are reported in Tables 2 and 3, respectively. For intratester reliability (Tab. 2), the values reported are the means of all the length measurements obtained for each test mode (LL and 3DD) for both the first and second test sessions (M1 and M2) by the tester indicated in the stub A small software routine placed into a program that provides a common function. Stubs are used for a variety of purposes. For example, a stub might be installed in a client machine, and a counterpart installed in a server, where both are required to resolve some protocol, remote procedure subheading sub·head·ing n. See subhead. subheading Noun the heading of a subdivision of a piece of writing Noun 1. of the table. For intertester reliability (Tab. 2), the values reported are the means of all the length measurements obtained by each tester for the measure indicated in the stub subheading of the table. in Table 3, the values are based on the mean of all measurements taken by the tester specified in the stub subheading on the data source object specified in the field heading with the test mode indicated in the field subheading. For example, the value 133.23 in the first row of values is the mean for tester I using the LL test mode on the BOX data source, and the value 132.80 in the fourth row of values is the mean for tester 2 using the 3DD test mode. The values for the reliability and validity coefficients (ICC and r) are presented in Tables 4 and 5, respectively. [TABULAR tab·u·lar adj. 1. Having a plane surface; flat. 2. Organized as a table or list. 3. Calculated by means of a table. tabular resembling a table. DATA OMITTED]
Table 4. Intraclass Correlation Coefficients for [Reliability.sup.a]
BOX CORNER SKELETON CURVES PAPER
Test [Mode.sup.b] (n=20) (n=30) (n=14) (n=88) (n=20)
LL
Intratester
Tester 1 .99 .99 .99 NT NT
Tester 2 .99 .99 .99 NT NT
Intertester
Measure 1 .99 .99 .99 NT NT
Measure 2 .99 .99 .99 NT NT
3DD
Intratester
Tester 1 .99 .99 .99 1.00 .99
Tester 2 .99 .99 .99 1.00 NT
Intertester
Measure 1 .99 .99 .99 1.00 NT
Measure 2 .99 .99 .99 1.00(*) NT
(a) Asterisk (*) indicates [F.sub.Testers] value was significant at P<.05; df=1,
19;
[F.sub.Critical]=4.38. NT indicates
condition was not tested.
([LL.sub.b]) = Line Length mode, 3DD=3-D Digitizer mode.
Table 5. Pearson Product-Moment Correlation Coefficients for [Validity.sup.a]
BOX CORNER SKELETON CURVES PAPER
Test [Mode.sup.b] (n=20) (n=30) (n=14) (n=88) (n=20)
LL versus actual
Tester 1 .99(*) 1.00 .99 1.00 NT
Tester 2 .99(**) 1.00 1.00 NT NT
3DD versus actual
Measure 1 .99 1.00 .99 .99 1.00(*)
Measure 2 .99(**) 1.00 .99 .99(*) 1.00(*)
3DD versus 3DD
Tester 1 .99 1.00 .99 .99 NT
Tester 2 .99 1.00 .99 .99 NT
(a) Asterisk (1) See Asterisk PBX. (2) In programming, the asterisk or "star" symbol (*) means multiplication. For example, 10 * 7 means 10 multiplied by 7. The * is also a key on computer keypads for entering expressions using multiplication. (*) indicates value of t test for repeated measures was significant at P<.05. See Table 3 for appropriate degrees of freedom and critical t values. Double asterisk (**) indicates value of t test for repeated measures was significant at corrected alpha level of .002 (Bonferroni adjustment), df=19, [t.sub.Critical]=3.579. NT indicates condition was not tested. ([LL.sup.b])=Line Length mode, 3DD=3-D Digitizer mode. Note in Tables 4 and 5 that across all comparisons, the lowest value for the ICC is .99 and the lowest value for the Pearson correlation coefficient is .99. A complete table of the F-ratio and t-test values is not included, but comparisons for which there were significant differences between repeated measures are identified in Tables 2 through 5. The [F.sub.Testers], value was statistically significant at the uncorrected alpha level of .05 for I of the 29 comparisons made to assess reliability. The repeated-measures t-test values were significant for 6 of the 25 comparisons made to assess the concurrent validity of the measurements. After adjustment of the alpha level by the Bonferroni method[13] for the total number of comparisons in each part of the study (29 for reliability and 25 for validity; adjusted alpha=.002), only 2 of the comparisons were still significant, as indicated in Table 5. Discussion One of the purposes of this study was to examine the reliability and validity of measurements obtained with two modes of the Metrecom (LL and 3DD) on several different inanimate objects. We optimized the possibility of achieving large reliability coefficients in several ways. We used (1) stationary inanimate objects with fixed markers, (2) only two testers, and (3) a range of lengths inconsistent with a truncated truncated adjective Shortened range (especially with the CORNER). Then we addressed the issue of whether reliable measurements could be obtained if objects and lengths somewhat similar to those typically encountered in a clinical setting were used by testing the following: (1) the SKELETON and CURVES and (2) a set of shorter lengths (on the PAPER) presumed to be within the range of lengths (reflecting changes in relative position of a specific anatomic landmark) that might be encountered as the result of some treatment intervention. Based on the data presented, the distance between pairs of points (lengths) can be measured reliably with the Metrecom, both by a single tester (intratester) and by two different testers (intertester) in either of two modes (3DD and LL) for a variety of lengths and intervals between tests on inanimate objects. The magnitudes of the ICCs were large, indicating a strong association between repeated measures. In addition, after correction of the alpha level for total number of comparisons, none of the [F.sub.tester], values were significant, indicating that there was no statistical evidence of systematic variation between repeated measures. The values of the ICC for reliability were slightly higher in this study than those reported previously. Hoyle et al[11] reported values of the ICC for measuring leg length of human subjects with the Metrecom ranging from .885 to .974. The differences in degree of reliability could be attributed at least in part to the use of human subjects rather than inanimate objects. It is encouraging to note from the Hoyle et al study that despite the potential for error in measurement on human subjects due to postural sway and difficulty in locating bony landmarks, the measurements were reliable. As indicated by the high levels of the correlation coefficients (.99-1.00) and nonsignificant t-test values for the comparisons used to assess concurrent validity of the 3DD and LL modes, there was consistency between measures of the same length with two different techniques. The LL mode correctly calculated distances between two points. It is not necessary, therefore, to perform the calculations manually using data derived from the 3DD mode. In examining the concurrent validity of the Metrecom measures and the tape measure (or ruler), the high values of the correlation coefficients (.99-1.00) and nonsignificant t-test results are indicative of acceptable consistency between measurements obtained from the different devices. Though there was statistical evidence for systematic differences between the measurements obtained from the two devices in 2 of the 17 comparisons, the only data source for which there were significant differences was the first object studied (BOX). The largest mean difference between measures occurred with the SKELETON. Technically, it was more difficult to take measurements with the tape measure than with the Metrecom on the SKELETON because of bony obstructions in the straight-line path between the bony landmarks specified for measurement. It remains to be determined in future studies whether the maximum mean difference of 3.29 mm is clinically relevant. In comparison with the results on human subjects reported by Hoyle et al[11] the maximum difference in the means of measurements taken with the tape measure and with the Metrecom on the SKELETON in our study was smaller (18.5 mm compared with 3.29 mm). As noted by Hoyle et al, the fact that the Metrecom is not affected by intervening obstructions may account for differences in measurements taken with the tape measure and the Metrecom. In human subjects, both soft tissue mass and bony obstructions could affect measurements taken with the tape measure. It is reasonable, therefore, that the differences between measurements obtained using the tape measure and the Metrecom may be larger for human subjects than for the SKELETON. Finally, we did not have access to a tape measure, ruler, or other device with precision equivalent to that of the Metrecom (0.1 mm). Final conclusions regarding the validity of the Metrecom length measurements as compared with actual length measurements, therefore, must await testing with a better measurement standard. Our decision to omit o·mit tr.v. o·mit·ted, o·mit·ting, o·mits 1. To fail to include or mention; leave out: omit a word. 2. a. To pass over; neglect. b. testing of the last two objects under some conditions was based on the following line of reasoning Noun 1. line of reasoning - a course of reasoning aimed at demonstrating a truth or falsehood; the methodical process of logical reasoning; "I can't follow your line of reasoning" logical argument, argumentation, argument, line . We were interested primarily in using the 3DD mode, but we also wanted to assess the interchangeability of measures from the LL and 3DD modes. The order in which objects of study were discussed in this article paralleled the chronological order of their testing. As testing progressed, we became convinced that the two modes produced similar measurements and then began to focus our testing on the 3DD mode only. Conclusions The Metrecom appears to provide reliable measurements of the distance between two points on inanimate inanimate /in·an·i·mate/ (-an´im-it) 1. without life. 2. lacking in animation. in·an·i·mate adj. , stationary objects. The measurements provided by two different modes of the Metrecom were consistent, but the validity of the Metrecom measurements compared with an external reference measure may need to be verified by use of a more precise alternate measurement system. It appears the Metrecom has the potential to be useful in a clinical setting for measuring distances between two points. Additional studies addressing the reliability and validity of measurements taken on human subjects are needed before a more definitive conclusion can be drawn about the appropriateness of using the Metrecom in a clinical setting. References [1] Kendall HO, Kendall FP, Boynton DA Posture and Pain. Malabar, Fla: RE Krieger Co; 1952. [2] Hellebrandt FA, Riddle KS, Fries EC. The influence of postural sway on stance photography, Physiother Rev, 1942;22:20-28. [3] Day JW, Smidt GL, Lehmann T. Effect of pelvic tilt pelvic tilt, n rotation of the pelvis around either a horizontal or vertical axis. The former cases would be forward or backward tilt, whereas the latter would tilt to the left or right side. on standing posture. Phys Ther 1984;64: 510-516. [4] Woodhull AM, Maltrud K, Mello BL. Alignment of the human body in standing. Eur J Appl Physiol, 1985;54:109-115. [5] Fox MG, Young OG. Placement of the gravital line in anteroposterior anteroposterior /an·tero·pos·te·ri·or/ (-pos-ter´e-er) directed from the front toward the back. an·ter·o·pos·te·ri·or adj. Abbr. AP 1. Relating to both front and back. standing posture. Research Quarterly 1954;25:277-285. [6] D'Angelo MD, Grieve grieve v. grieved, griev·ing, grieves v.tr. 1. To cause to be sorrowful; distress: It grieves me to see you in such pain. 2. DW, Pereira LF, Watkinson T. A description of normal relaxed standing postures. Clin Biomech. 1987;2:140-144. [7] Burdett RG, Brown KE, Fall MP. Reliability and validity of four instruments for measuring lumbar spine Lumbar spine The segment of the human spine above the pelvis that is involved in low back pain. There are five vertebrae, or bones, in the lumbar spine. Mentioned in: Low Back Pain and pelvic pelvic /pel·vic/ (pel´vik) pertaining to the pelvis. pel·vic adj. Of, relating to, or near the pelvis. positions. Phys Ther. 1986;66:677-688. [8] Moll JMH JMH Jackson Memorial Hospital JMH Schaumburg, Illinois (Airport Code) JMH JSSIS Message Handler JMH James Monroe High school JMH Joint Message Holder (US DoD) , Wright V. Normal range of spinal mobility. Ann Rheum rheum (rldbomacm) any watery or catarrhal discharge. rheum n. A watery or thin mucous discharge from the eyes or nose. rheum any watery or catarrhal discharge. Dis (Lond). 1971;30: 381-386. [9] Anderson JAD (Joint Application Development) An approach to systems analysis and design introduced by IBM in 1977 that emphasizes teamwork between user and technician. Small groups meet to determine system objectives and the business transactions to be supported. , Sweetman BJ. A combined flexi-rule/hydrogoniometer for measurement of lumbar spine and its sagittal sagittal /sag·it·tal/ (saj´i-t'l) 1. shaped like an arrow. 2. situated in the direction of the sagittal suture; said of an anteroposterior plane or section parallel to the median plane of the body. movement. Rheumatol Rehabil. 1975;14:173-179. [10] Gajdosik R, Simpson P, Smith R, DonTigny RL. Intrateste reliability of measuring the standing position and range of motion. Phs Thr. 1985;65:169-173. [11] Hoyle DA, Latour M, Bohannon RW. Intraexaminer, enterexaminer, and interdevice comparability of leg length measurements obtained with measuring tape and Metrecom. Journal of Orthopaedic and Sports Physical Therapy, 1991;14:263-268. [12] Lahey MA Downey RG, Saal FE. Intraclass correlations: There's more there than meets the eye. Psychol Bull. 1983;93:586-595. [13] Hayes WL. Statistics. New York New York, state, United States New York, Middle Atlantic state of the United States. It is bordered by Vermont, Massachusetts, Connecticut, and the Atlantic Ocean (E), New Jersey and Pennsylvania (S), Lakes Erie and Ontario and the Canadian province of , NY. Holt, Rinehart & Winston Inc; 1981:299. |
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