Ultrasound-assisted bony landmark palpation in untrained palpators

Medical students with no previous experience may find it difficult to identify and palpate bony landmarks while learning physical examination skills. In a study of 168 medical schools, 72.6 % have indicated that they are utilizing ultrasound in their curriculum. Although the integration of ultrasound curriculum has become more widespread, the depth of instruction is inconsistent. Ultrasound is not commonly taught in conjunction with palpation of bony landmarks in osteopathic structural examination.

The objective of this analysis was to identify whether utilizing ultrasound assistance in teaching palpation of specific thoracic vertebral bony landmarks would improve palpation accuracy in first-year medical students with no previous palpatory experience.

First-year medical students were given video instructions to palpate and identify a thoracic vertebral transverse process and to mark it with invisible ink. The participants were then taught and instructed to utilize ultrasound to identify the same landmark and mark it with a different color. The accuracy of palpation was measured with digital calipers.

A test of the overall hypothesis that participants will show improved accuracy utilizing ultrasound compared with hand palpation was not significant (F=0.76, p>0.05). When separating students into groups according to patient body mass index (BMI), however, there was a trend toward significance (F=2.90, p=0.071) for an interaction effect between patient BMI and the repeated measures variable of palpation/ultrasound. When looking specifically at only those participants working with a normal BMI patient, there was a significant improvement in their accuracy with the use of ultrasound (F=7.92, p=0.017).

The analysis found increased accuracy in bony landmark identification in untrained palpators utilizing ultrasound vs. palpation alone in a normal BMI model, but not in obese or overweight BMI models. This study shows promise to the value that ultrasound may have in medical education, especially with respect to early palpation training and landmark identification.