An Investigation into the Validity of Cervical Spine Motion Palpation Using Subjects with Congenital Block Vertebrae as a 'Gold Standard'
 
   

An Investigation into the Validity of Cervical Spine
Motion Palpation Using Subjects with Congenital Block
Vertebrae as a 'Gold Standard'

This section is compiled by Frank M. Painter, D.C.
Send all comments or additions to:
   Frankp@chiro.org
 
   

FROM:   BMC Musculoskelet Disord 2004 (Jun 15);   5 (1):   19 ~ FULL TEXT

Humphreys BK, Delahaye M, Peterson CK


BACKGROUND:   Although the effectiveness of manipulative therapy for treating back and neck pain has been demonstrated, the validity of many of the procedures used to detect joint dysfunction has not been confirmed. Practitioners of manual medicine frequently employ motion palpation as a diagnostic tool, despite conflicting evidence regarding its utility and reliability. The introduction of various spinal models with artificially introduced 'fixations' as an attempt to introduce a 'gold standard' has met with frustration and frequent mechanical failure. Because direct comparison against a 'gold standard' allows the validity, specificity and sensitivity of a test to be calculated, the identification of a realistic 'gold standard' against which motion palpation can be evaluated is essential.

OBJECTIVES:   The objective of this study was to introduce a new, realistic, 'gold standard', the congenital block vertebra (CBV) to assess the validity of motion palpation in detecting a true fixation.

METHODS:   Twenty fourth year chiropractic students examined the cervical spines of three subjects with single level congenital block vertebrae, using two commonly employed motion palpation tests. The examiners, who were blinded to the presence of congenital block vertebrae, were asked to identify the most hypomobile segment(s). The congenital block segments included two subjects with fusion at the C2-3 level and one with fusion at C5-6. Exclusion criteria included subjects who were frankly symptomatic, had moderate or severe degenerative changes in their cervical spines, or displayed signs of cervical instability. Spinal levels were marked on the subject's skin overlying the facet joints from C1 to C7 bilaterally and the motion segments were then marked alphabetically with 'A' corresponding to C1-2. Kappa coefficients (K) were calculated to determine the validity of motion palpation to detect the congenitally fused segments as the 'most hypomobile' segments. Sensitivity and specificity of the diagnostic procedure were also calculated.

RESULTS:   Kappa coefficients (K) showed substantial overall agreement for identification of the segment of greatest hypomobility (K=0.65), with substantial (K=0.76) and moderate (K=0.46) agreement for hypomobility at C2-3 and C5-6 respectively. Sensitivity ranged from 55% at the C5-6 CBV to 78% at the C2-3 level. Specificity of the procedure was high (91 - 98%).

CONCLUSIONS:   This study indicates that relatively inexperienced examiners are capable of correctly identifying inter-segmental fixations (CBV) in the cervical spine using 2 commonly employed motion palpation tests. The use of a 'gold standard' (CBV) in this study and the substantial agreement achieved lends support to the validity of motion palpation in detecting major spinal fixations in the cervical spine.


From the Full-Text Article:

Discussion

This study was unique in employing an in-vivo gold standard of fixation in the form of congenital block vertebrae. It allowed the validity of motion palpation in the detection of segmental hypomobility to be evaluated, whilst omitting some of the experimental design limitations, which confined and confounded the previous studies.

Although previous studies have cast significant doubt on the reliability and validity of motion palpation for the diagnosis of a manipulable lesion [21-26,28], clinicians still continued to use this procedure in their practices. Their clinical judgment appeared to take precedence over the research findings. Perhaps these clinicians, functioning in the reality of the practice situation, sensed the limitations of the research settings and still felt that they were able to detect the individual fixation/s. The results of this study suggest that even student examiners, with less experience than practicing clinicians, were able to detect the presence or absence of 'fixation' in the cervical spine using specific motion palpation techniques in lateral flexion and rotation. The overall Kappa value of K = 0.675 represents substantial agreement beyond chance. These positive findings support the clinical use of motion palpation, and are arguably the most significant to date, since previous investigations have provided little evidence of the accuracy, validity or reliability of this procedure [28] .

The degree of agreement reflected in these results may be accounted for by the use of an in-vivo gold standard, which closely approximates a true fixation. Not only is no motion allowed at the level of the CBV, but as previously described, the anomaly can result in increased motion and potential instability at adjacent motion segments [37]. The relative 'fixation' feel at the CBV would therefore be enhanced, and its detection further facilitated. The high Kappa values obtained in this study may also have been assisted by the marking of the IVMUs on the subjects.

The results, while not flawless, are encouraging in considering that even the most fundamental orthopaedic procedures have been shown to have less than perfect specificity and sensitivity [38]. An attempt was made in this study to limit variation in palpatory technique used by the examiners, in order to increase the tests reproducibility. The use of examiners with the same training and experience, as well as specific instruction as to the techniques to be used, served to standardize the motion palpation procedures performed, and may be one factor which contributed to the relatively high specificity and sensitivity scores.

Kappa coefficients for the different levels of CBV were also calculated to determine whether there was a difference between the validity of motion palpation at the different levels of the cervical spine. Palpation of the two patients with C2-3 CBV indicated substantial agreement (K = 0.756), whilst moderate agreement (K = 0.460) was indicated in the subject with the C5-6 block. In a normal cervical spine there is greater motion allowed at the C5-6 motion segment than at more superior segments, and one might therefore expect a total lack of motion at this C5-6 level to be easier to identify. However, this increased motion at C5-6 is particularly in the directions of flexion and extension, whereas the motion palpation evaluated in this study was in rotation and lateral flexion. Additionally, most people have more muscle and other overlying soft tissues in the mid and lower cervical spine through which to palpate, as compared to the more superficial C2-3 region. This may have contributed to the difference in results. It must also be pointed out that only 3 patients were included in this study, with only one having CBV at the C5-6 level. Therefore the discrepancy in these results may simply have been due to idiosyncrasies in the individual patients.

It was interesting to note that when palpating the subject with the C5-6 block, many examiners identified an upper cervical segment (C1-2 or C2-3) as the most hypomobile. It is possible that a true vertebral 'dysfunction' was present at the higher segment, causing a number of examiners to implicate it as their most hypomobility finding. The choice of this segment over the CBV caused the validity of motion palpation as assessed by this project design to decrease. Although it is unlikely that the kinesiopathology of a true vertebral dysfunction/fixation would affect greater hypomobility than a congenital fusion, it is possible that other manifestations of the 'joint dysfunction complex' were evident and detected by examiners. Despite simply being requested to identify fixation, other indicators of a joint dysfunction were being appreciated by the examiners. This suggests that when using motion palpation, examiners integrate the sense of kinesiopathology, with an appreciation of temperature change, muscle tension, tenderness, swelling, non-verbal pain response, as well as their instinctive ability to detect the site of the lesion.


Limitations to the study

In addition to the limitations stated above, the use of a congenital block vertebra in the validation of motion palpation has its limitations. The number of suitable subjects is restricted by the prevalence of the anomaly and the absence of complicating factors such as spinal degeneration, instability and pain.

Whereas previous motion palpation studies have used a pair of examiners and 40 patients/subjects, due to the scarcity of suitable patients with CBV, the number of examiners had to be increased in order to have the same inferential power. This posed the problem of subject comfort, since even the most gentle application of motion palpation technique repeated over 20 times is likely to cause the subject discomfort. The use of so few patients also makes it difficult to separate any clinically relevant results from those attributable to the patient idiosyncrasies, and is likely to induce greater change in the minor fixation findings.


Conclusions

The results of this study indicate that even novice clinicians demonstrated the ability to correctly identify the presence or absence of known cervical spine intersegmental fixations by using specific motion palpation techniques on real patients with congenitally fused vertebrae. These congenital blocked vertebrae represent a true 'gold standard', allowing more accurate evaluation of the validity of motion palpation. The results of this study justify the clinical use of motion palpation in the diagnosis of true 'fixations' in the cervical spine.


Return to ChiroZINE ARTICLES

Return to ABOUT SPINAL ADJUSTING/MANIPULATION

Since 6-18-2004

             © 19952014    The Chiropractic Resource Organization    All Rights Reserved