Intra and interexaminer reliability of motion palpation in ... - Europe PMC

Intra and interexaminer reliability of motion palpation in the cervical spine* Silvano A. Mior, DC, FCCS(C)t Ronald S. King, DCt Marion McGregor, DC, FCCS(C)t Marc Bernard, DCtt

A pilot study was undertaken to evaluate the intra- and interexaminer agreement in passive motion palpation of the upper cervical spine. Sixty-two subjects were examined by two examiners, who were in their final year of clinical training. The observed results compared quitefavourably with those reported in similar studies, however, agreement beyond chance ranged from 15 to 52 percent. Three issues which require consideration for future research are: role of asymptomatic subjects, student expectations, and the use of student examiners. KEY WORDS: Examiner reliability, motion palpation, cervical spine, chiropractic, manipulation.

Une etude pilote a ete entreprise afin d'evaluer l'entente intra et inter de 1'examinateur dans une palpation de motion passive de la colonne cervicale superieure. Soixante-deux sujets ont ete' examines par deux examinateurs qui en etaient a leurt derniere annee de formation clinique. Les resultats observes se comparentfavorablement avec ceux rapportes dans des etudes similaires; cependant, l'entente au-dela de tout doute etait de l'ordre de 15 a 52%. Voici les questions qui meritent consideration pour les recherches futures: le role des subjets asymptomatiques, les attentes des etudiants, et l'emploi d'examinateurs etudiants. MOT CLES: fiabilite de l'examinateur, palpation de motion, colonne cervicale, chiropraxie, manipulation.

Introduction

clusions drawn. In the present pilot project, we wished to assess the intra and interexaminer reliability of chiropractic interns on a motion palpation technique for the upper cervical spine. It was intended both to determine the percentage observed agreement, as well as the agreement beyond chance, in order to draw conclusions for further work in this area.

In recent years, spinal motion palpation tests have become increasingly popular in the clinical assessment of chiropractic patients. In spite of this, relatively few data are available regarding either the validity or the reliability of these procedures. Most authors interested in evaluating motion palpation techniques began by assessing intra and interexaminer agreement under various circumstances. McConnell et all tested a group of osteopathic physicians who used their choice of procedures, while Mann, Glasheen-Wray and Nyberg2 observed agreement in both students and physical therapists palpating iliac crest heights. Such diversity in the literature has made it difficult to draw conclusions. The issue has been further complicated by highly descriptive analyses of results in most papers. Kaltenborn and Lindahl3 in 1969, determined interexaminer agreement among 9 examiners on 4 patients, using the most experienced examiner as the standard for comparison. He concluded that their observed results were remarkably good. Gonnella, Paris and Kutner' in 1982 concluded that intratherapist reliability was dependable, while intertherapist reliability was not. The measures by which the last two papers drew such conclusions were not specified. The most common assessment made on examiner reliability results for motion palpation techniques has been the calculation of observed interexaminer agreement. Ranges for observed agreement have been cited from 36 to 100% over various studies5'6. It has not been common practice to determine the percent agreement above and beyond chance, although such figures would certainly clarify the findings and affect the conC S Mior, R King, M McGregor, M Bernard 1985 * Presented at the Second Annual FCER Conference, Illinois, Oct. 14, 1983. Supported in part by a grant from the Canadian Memorial Chiropractic College. t Clinician, Canadian Memorial Chiropractic College, 1900 Bayview Ave., Toronto, Ontario, M4G 3E6. tt Research Assistant, Canadian Memorial Chiropractic College.

The Journal of the CCA/Volume 29 No. 4/December 1985

Method Two examiners and one observer in their final year of clinical training were given special instructions over a 3 month interval to ensure conformity in their method of palpation and record-

ing. The examiners evaluated the joint play of the atlas in right and left lateral bending and anterior rotation. In anterior rotation, the palpating finger tips were placed on the posterior aspect of the transverse process/lamina junction at C, and C2. The indifferent hand cradled and supported the head on the contralateral side (Fig. lA). The examiner then rotated the head of the subject passively through the physiological range of movement. At the end of this range, the examiner accentuated the motion, thereby challenging the joint play and evaluating the end feel (Fig. IB). The examiner then informed the observer if the end feel was normal or if there was a fixation of the atlas, either on the right or the left. A fixation was interpreted as a loss in the joint play resulting in a hard end feel within the passive range of movement of the joint. The examiner then proceeded to evaluate right and left lateral bending. The palmar aspect of the indifferent hand supported the head in the occipital region. The palpating finger tip of the other hand was placed on the lateral aspect of the transverse process of the atlas on the opposing side (Fig. 2A). A lateral movement was produced by the indifferent hand in the direction of the palpating fingertips. Again, when the end range had been reached, the palpating finger accentuated the lateral movement of the atlas and the examiner evaluated the end feel of 195

Motion palpation

Figure 1-A,B: Contact position for palpation in anterior rotation.

Figure 2-A,B: Contact position for palpation in lateral flexion.

the joint (Fig. 2B).

Each subject was evaluated on 2 separate occasions by each examiner. One subject did not return for re-examination by examiner 2. Thus, this examiner's results have been calculated on the basis of 58 pairs of observations. The interexaminer agreement was calculated by comparing the initial examination of each subject between the two examiners. Therefore, 59 pairs of observations were available.

Sixty-two subjects, ranging in age from 22-30 years, were randomly selected from the student body at the Canadian Memorial Chiropractic College. Each subject was evaluated prior to testing and was excluded if there was a painful limitation in cervical movement. This left 59 subjects for evaluation by the examiners. Subjects were led into the examination room and instructed to lie supine on the examination table. The examiners who were blindfolded, were directed to the head of the table where they sat on a stool. The observer instructed the examiner to proceed to palpate the atlas in relationship to the occiput and the axis. There was no comunication between examiner and subject. The palpatory findings were relayed to the observer, who recorded them as either a normal finding or a fixation of the atlas. It was felt, that since this was a pilot study, the concern for grading a lesion, as others have done, would not be entertained. 196

Results Intraexaminer agreement is illustrated by the histograms in figure 3. Both examiners detected a fixation in approximately 20 percent of subjects and a normal finding in approximately 50-60 percent. The histogram in Figure 4, illustrates the interexaminer agreement. Both examiners detected the same fixation in 15 percent of the cases and a normal finding in 40 percent. Percentage agreement calculated form the histograms determined the observed intraexaminer agreement for examiner 1 The Journal of the CCA/Volume 29 No. 4/December 1985

Motion palpation

INTRAEXAMINER RELIABILITY

at 71 percent and for examiner 2 at 79 percent. The interexaminer agreement was 61 percent. Tables 1 and 2 give the kappa scores for reliability. For examiner 1, kappa was calculated at 0.37 and for examiner 2 was 0.52. The kappa value for interexaminer agreement was found to be 0.15.

Discussion

FIXATION

F IXAT ION

The observed intraexaminer agreements for these student examiners were 71 and 79 percent. Their interexaminer agreement was 61 percent. As expected, the figures fit well within the range of observed agreement determined by previous

NORMAL

studies3'4'5. INTRAEXAMINER AGREEMENT

22

FIXATION

NORMAL

NORMAL

12

F IXAT ION

24

10

60

NORMAL

14

68

KAPPA = 0.52

KAPPA = 0. 37

Table 1: The kappa values for the intraexaminer reliability of examiners 1 and 2.

60

INTEREXAMINER RELIABILITY EXAMINER 2

50 PERCENT OF

EXAMINER 2

EXAMINER I

40

FIXATION

PATIENTS

NORMAL

30

cc

20

FIXATION

17

20

NORMAL

25

56

z 10

X LU

x Figure 3: Histogram illustrating the intraexaminer agreement of examiners 1 and 2.

INTEREXAMINER AGREEMENT 50 40

PERCENT OF

30

PATIENTS

20

10

_m

-m

Figure 4: Histogram illustrating the interexaminer agreement.


KAPPA = 0.15

Table 2: The kappa value for the interexaminer reliability.

On further analysis, agreement beyond chance indicated a true intraexaminer reliability of 37 and 52 percent and an interexaminer reliability of only 15 percent. While this appears initially shocking, these results are better evaluated by remembering that the degree of interexaminer agreement beyond chance was measured at only 14 to 64 percent in medical physicians examining the presence or absence of signs of airway obstruction in 19697. Although it is important to note that problems with examiner reliability are universal, it is equally important to attempt to understand why such problems exist, and how they might be rectified. First, a major difficulty arises with the use of asymptomatic subjects. It has been speculated5, that asymptomatic subjects are more likely to have minor lesions which may be affected by repeated evaluations. Next is the poorly understood role of examiner expectations. When comparing the histogram of examiner 1 alone and that of examiner 2 alone, the number of positive and negative find197

Motion palpation

ings are strikingly similar. However, compared to the overall interexaminer observations, it is obvious that while the number of events was much the same, the location of the findings was not. It is unknown whether students and clinicians have learned to expect a certain number of biomechanical spinal problems. Possibly students are inadvertently being taught to search out what they believe they should find (known as: entrapment by prior expectation) rather than what is actually there. Certainly, chiropractic is not alone in this dilemma. Feinstein alluded to this when he described observer variability and the unquestioning acceptance of the teacher or "chief's" word, in any physical observation8. In discussing clinical disagreement, Sackett further illustrated this point using the classic 1945 example of "pseudodoxia pediatrics''9. In this study 389, 11 year-old school children were examined by a group of physicians. Forty-five percent of these were recommended for tonsillectomy. The apparently normal remaining group of children were evaluated by a second group of physicians and 46 percent were recommended for tonsillectomy. The remaining "normnals" were evaluated a third time by a third group of physicians and this time 44 percent were recommended for tonsillectomy. The role prior expectation plays in clinical disagreements is as yet unexplored. Perhaps with research here, we will find one of the keys to improving the diagnostic skills of the young graduate. Finally, one would expect less than optimal results in this study by the very use of chiropractic interns. On the conclusions of authors such as Kappler'0, Mann, Glasheen-Wray, and Nyberg2 and Wiles6, student examiners would be expected to have lesser capabilities and thus less reliability than experienced clinicians. Kappler, in fact, specified that student examiners were unable to "filter out" minor findings. As these findings are most susceptible to change during palpatory procedures, examiner reliability is obviously hampered. In future research using students, the assignment of a kappa of 0.8 during the teaching of motion palpation should aid students in "filtering out" minor findings, as well as, increase the reliability of this problem group. In conclusion, more research is required to understand clinical variability in motion palpation findings. Issues such as the type of patient employed as the subject, student expectations, and the role of student examiners must be addressed in the future for a fair analysis of the art of palpation.

Acknowledgements: The authors wish to thank Jim Delgrande for his input in data analysis, Marjorie Davis for the typing of the manuscript, Scott Wood for the photography, and the participating interns from the class of '83.

tests. JAOA 1980;79:432. 2 Mann M, Glasheen-Wray M, Nybert R. Therapist agreement for palpation and observation of iliac crest heights. Physical Therapy 1984; 3 Kaltenborn F, Tindahl 0. Reproducibility of the results of manual mobility testing of specific intervertebral segments. Swedish Medical Journal 1969;66;962. 4 Gonnella C, Paris S, Kutner M. Reliability in evaluating passive intervertebral motion. Physical Therapy 1982;62(4):436. 5 Johnston W. Interexaminer reliability in palpation. JAOA 1976;76;286. 6 Wiles M. Reproducibility and interexaminer correlation of motion palpation findings of the sacroiliac joints. JCCA 1980;24(2):59. 7 Godfrey S, Edwards RH, Campbell, EJ. Repeatability of physical signs in airway obstruction. Thorax 1969;24:4. 8 Feinstein AR. Clinical judgement. New York, Krieger, 1976. 9 Sackett DL. Clinical disagreement. 1. How often it occurs and why. CMA Journal 1980;123:499. 10 Kappler RE. A comparison of structural examination findings obtained by experienced physician examiners and student examiners on hospital patients. JAOA 1980;79:468-471.

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References 1 Beal M, Goodridge J, Johnston A, McConnell D. Interexaminer agreement on patient improvement after negotiated selection of

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