Prediction Model for Choosing Needle Length to Minimize Risk of Median Nerve Puncture With Dry Needling of the Pronator Teres

J Manipulative Physiol Ther. 2019 Jun;42(5):366-371. doi: 10.1016/j.jmpt.2018.11.020. Epub 2019 Jun 29.


Objective: The aim of this study was to relate forearm anthropometric measures to ultrasound pronator teres depth to determine the necessary needle length to prevent median nerve (MN) injury during pronator teres dry needling.

Methods: We conducted a study employing a diagnostic accuracy prediction model (NCT03308279) at a Spanish university center. The study recruited 65 participants to predict the depth of the MN (measured with ultrasound) in the pronator teres using a decision tree algorithm to reduce the risk of MN puncture using 2 needle lengths (13 mm or 25 mm). The decision tree was developed by automatically selecting a cutoff for body mass index, forearm length and circumference, and pronator teres thickness.

Results: For forearm circumferences ≤27.5 cm, the predictive value for the 13-mm needle was 92%. For forearm circumferences >27.5 cm and forearm lengths ≤26.75 cm, the predictive value for the 25-mm needle was 100%.

Conclusion: Based upon the findings of this study, we suggest that needle length should be selected according to forearm anthropometric measures to prevent MN injury during pronator teres dry needling.

Keywords: Acupuncture; Median Nerve; Musculoskeletal Diseases; Myofascial Pain Syndromes; Rehabilitation.

MeSH terms

  • Adult
  • Algorithms
  • Decision Trees
  • Dry Needling*
  • Female
  • Forearm / anatomy & histology
  • Humans
  • Iatrogenic Disease / prevention & control
  • Male
  • Median Nerve / diagnostic imaging*
  • Muscle, Skeletal / diagnostic imaging*
  • Peripheral Nerve Injuries / prevention & control
  • Sampling Studies
  • Ultrasonography