Original research
Accuracy of Motion Palpation Flexion-Extension Test in Identifying the Seventh Cervical Spinal Process

https://doi.org/10.1016/j.jcm.2017.11.005Get rights and content

Abstract

Objective

The aim of this study was to evaluate the accuracy of a motion palpation procedure, the flexion-extension test, in localizing the spinous process of the seventh cervical vertebra (C7).

Methods

We analyzed 101 adult participants with metal markers that permitted the identification of the C7 spinous process. This analysis occurred during a flexion-extension test and was confirmed by radiography. Data sample characteristics were analyzed by descriptive statistics, and the relationship between independent variables (weight, height, sex, age, and body mass index [BMI]) and dependent variables (coincidence between the most prominent vertebra and the stationary vertebra, as determined by the flexion-extension test) was determined via logistic regression.

Results

The sample population was 48.5% male with a mean age of 56.8 years (standard deviation, ±14.9) and a mean BMI of 25.54 kg/m2 (standard deviation, ±5.5). In 54.5% of cases, the C7 spinous process was correctly identified by the flexion-extension test. The agreement between the flexion-extension test and radiography in accuracy of localization of the C7 spinous process was significant (P = .021), as was the correct localization of C7 (P = .05).

Conclusion

The localization of the C7 spinous process was more accurate in individuals with a BMI <25 kg/m2 and whose most prominent vertebra coincided with the stationary vertebra as determined by the flexion-extension test.

Introduction

Motion palpation is used to determine the position of structures and localize vertebral levels. It is an important tool for the evaluation and treatment of musculoskeletal disorders and for diagnostic and therapeutic procedures in other areas, such as orthopedic surgery and anesthesia.1 Specifically, in the musculoskeletal area, knowledge of palpatory procedures can be considered an essential requirement for physical examination of vertebral structures.2 According to Najm et al,3 the beneficial results of vertebral manipulative procedures are based on skillful and appropriate treatments, which, in turn, are based on accurate diagnoses that are dependent on accurate palpatory procedures. Within the framework of medicine, physiotherapy, nursing, and osteopathy, palpation training is fostered in the early period; to unify this information, a systematic teaching of palpatory anatomy should be established.

Methods to correctly identify vertebral levels by palpation have been described for the lumbar, thoracic, and cervical regions; however, none are satisfactorily reliable.4 In a systematic review, Cooperstein et al5 pointed out that anatomically incorrect landmark benchmarks would hinder the accurate identification of spinal sites of clinical interest, beyond what is to be expected as a result of examiner error and variation among patients, which lends some value to a systematic review of the literature addressing other commonly used spinal landmark rules.5

Compared with reliability studies, the accuracy of palpation has not received the same emphasis in the literature. This may be due to the difficulty of finding a gold standard to objectively measure the vertebral level being palpated and consequently the accuracy of this procedure.6 Despite the importance of motion palpation, information on the validity and reliability of palpatory methods is scarce in the literature.7, 8

In their systematic review, Stochkendahl et al9 found numerous criticisms of the methods for palpatory studies, mainly because of uncontrolled factors such as the inclusion of asymptomatic participants only, inexperienced observers, parallel testing, less conclusive definitions of positive findings and rating scales, and weak descriptions of the results; all of these factors drive the need to improve the quality of studies. In addition, the possible relationships between anthropometric variables, such as weight, height, body mass index (BMI), age, and sex, and the accuracy of localization of the C7 spinous process have not been well explored in the literature. Studies that have tried to analyze the relationship between BMI and sex have reported inconclusive results, only highlighting these factors as potential study limitations.4, 10 In their last systematic review, Póvoa et al11 identified few studies that evaluated the validity of manual palpatory procedures for examining bony landmarks of the cervical spine. They reported fair to good methodologic quality with poor external validity as a result of the sampling heterogeneity.

Based on these studies and the lack of rigorous methodologic research in palpation, there is a need to systematize palpation of the cervical spine. Investigation of the accuracy of the procedure and how anthropometric features (weight, height, BMI, and age) may affect outcomes is needed. Therefore, the objectives of this study were to (1) assess the accuracy of the motion palpation procedure (flexion-extension test) in locating the C7 spinous process; (2) determine the agreement between the localization of the most prominent vertebra and the localization of the stationary vertebra (C7) using the flexion-extension test; and (3) verify the possible agreement of the accuracy of the C7 spinous process localization with the independent variables of weight, height, sex, age and BMI and the dependent variables of agreement between the most prominent vertebra and the stationary vertebra, as determined by the flexion-extension test.

Section snippets

Methods

This study used a convenience sample, with a total population selected consecutively. The structure of the study is shown in Figure 1.

Results

Of the 127 individuals invited for the study, 26 were excluded because of changes in the positioning of the film that directly contributed to viewing limitations of the radiologic image and exclusion the region of interest, thus preventing an analysis of the cervical region.

The data characterizing the sample were analyzed using descriptive statistics with central tendency values (mean and median) and dispersion (standard deviation). According to the Kolmogorov-Smirnov test, the study population

Discussion

According to our results, the accuracy of the flexion-extension test for the localization of the spinous process of C7 confirmed by radiography was 54.5%. Our findings are consistent with the work of Robinson et al.13 In Robinson's work, the evaluators were more precise than accurate (there was agreement on the localization, but it was not in an accurate location) because the C7 localization was agreed upon in 12 of 18 participants evaluated, but the spinous process of C7 was correctly

Conclusion

After analysis, flexion-extension test accuracy (confirmed by the radiography images) was identified in 54.5% of participants (n = 55). Regarding the association between the most prominent vertebra (static position) and C7 determined by the flexion-extension test (motion test), 65.4% (n = 65) did not coincide, and 35.6% (n = 36) were in agreement. To be more accurate, the localization of the most prominent vertebra should be at the same level as the localization of the stationary vertebra (C7)

Funding Sources and Conflicts of Interest

No funding sources or conflicts of interest were reported for this study.

Contributorship Information

  • Concept development (provided idea for the research): L.C.P., A.P.A.F., J.F.C.Z., J.G.S.

  • Design (planned the methods to generate the results): L.C.P., A.P.A.F., J.F.C.Z., J.G.S.

  • Supervision (provided oversight, responsible for organization and implementation, writing of the manuscript): L.C.P., A.P.A.F., J.F.C.Z., J.G.S.

  • Data collection/processing (responsible for experiments, patient management, organization, or reporting data): L.C.P., A.P.A.F., J.F.C.Z., J.G.S.

  • Analysis/interpretation

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