The Journal of the American Osteopathic Association, 2005/07, 105(7):319. doi: 10.7556/jaoa.2005.105.7.317, type of study: ,obs,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,

Full text    (https://www.degruyter.com/document/doi/10.7556/jaoa.2005.105.7.317/html)

Keywords:

diagnosis [412]
observational study [246]
palpation [217]
proprioception [19]
thoracic spine [98]

Abstract:

Hypothesis: Cutaneous mechanoreceptors and muscle proprioceptors both contribute to medical palpation. The relative importance of these modalities in osteopathic palpatory diagnosis is unknown, and objective methods of measuring palpatory skill are lacking. We investigated the relative importance of cutaneous feedback from the index finger vs. proprioceptive feedback from the upper extremity to osteopathic medical students’ ability to identify: Tissue texture change, Asymmetry, and Restriction to motion; utilizing a virtual reality simulation of somatic dysfunction, the Virtual Haptic Back (VHB), currently under development at Ohio University. Methods: Year 1 & 2 students’ ability to identify randomly selected thoracic vertebrae, 1) rotated out of position, or 2) stiff to rotation, at 3 successive levels of difficulty was tested on 4 different days over 2 weeks. 2 trials of each task, following orientation, were run daily. Days 1 & 4: both trials run without anesthesia. Days 2 & 3: first trial was without anesthesia. For the second trial, subjects were randomized to receive either topical anesthesia (EMLA cream - lidocaine + prilocaine), or digital block (2% lidocaine) on day 2, and received the other anesthetic day 3. Anesthetic efficacy was documented with von Frey hairs. Muscle spindles in the muscles controlling the palpating fingers were presumably unaffected. Computers recorded elapsed time and number of errors before correct identification of dysfunctional vertebra. Subjects were provided voice feedback as to whether or not they chose correctly. Results: RMANOVA revealed no statistically significant (P.05) increases in number of incorrect responses or time required to perform either task, with either form of anesthesia. Conclusions: Palpatory information needed to perform these 2 tasks on the VHB appears not to be dependent upon superficial receptors subject to topical anesthesia, (Meissner’s corpuscles and Merkel’s disks), nor upon deeper cutaneous receptors subject to digital block, (Pacinian and Ruffini’s corpuscles); but on proprioceptors from the upper extremity.