A simulated passive intervertebral motion task: observations of performance in a cross-sectional study

Abstract

Introduction: Passive motion palpation is an integral component in examination, diagnosis or classification, and treatment of persons with mechanical disorders of the cervical spine. If the magnitude of force application during passive movement assessment is associated with greater palpatory accuracy has not been established. Methods: This investigation used a novel mechanical model as a basis for assessing the palpatory force of students and clinicians. The model included multiple palpable resistance and displacement levels similar to that observed in humans. The ability of the subjects to discriminate the various levels of resistance and displacement offered by the model was concurrently measured. Results: Large variability occurred in the amount of force applied by the subjects in completing the palpatory examination. The data indicated no major differences in palpatory accuracy across the student and clinician groups with different training and experience levels beyond basic competency. Those subjects applying less force in the palpatory exam demonstrated greater accuracy of palpatory assessment with one measure. Discussion: The data indicate training and experience had minimal relationship to palpatory interpretation precision beyond the basic level and individual natural discriminatory ability may be a factor in accuracy of palpatory skill. The results demonstrate remarkable inconsistency in palpatory force among examiners and suggest that palpatory accuracy may be related to less force application.

Spinal PA movements behave ‘as if’ there are limitations of local segmental mobility and are large enough to be perceivable by manual palpation: A synthesis of the literature

“…One study has evaluated therapists' ability to perceive differences that are directly related to those that occur with PA movements. [35] A mechanical model of the cervical spine was developed to determine the ability of examiners to perceive subtle differences in stiffness and motion with PA movements as might occur in vivo. The model was different from previous devices in that it incorporated three-point bending, allowing multi-segmental movement when pressure was applied to a single simulated vertebra and had both viscoelastic characteristics and a neutral zone of each segment that could be adjusted.…”