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

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).

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.

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).

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.