Related Experiment Video

Updated: Jun 4, 2026

Development of a Neonatal Rat Model for Brachial Plexus Birth Injury
09:42

Development of a Neonatal Rat Model for Brachial Plexus Birth Injury

Published on: March 27, 2026

EMG and MRI are independently related to shoulder external rotation function in neonatal brachial plexus palsy

Robert J Talbert1, Linda J Michaud, Charles T Mehlman

  • 1Division of Pediatric Orthopaedics, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Avenue, MLC 2017, Cincinnati, OH 45229, USA.

Journal of Pediatric Orthopedics
|February 11, 2011
PubMed

Insights

Electromyography (EMG) and MRI of the infraspinatus muscle can help assess shoulder function in neonatal brachial plexus palsy (NBPP). These tests, combined with clinical evaluation, improve diagnosis and treatment guidance for NBPP patients.

Area of Science:

  • Orthopedics
  • Neurology
  • Radiology
  • Physical Medicine and Rehabilitation

Background:

  • Limited research exists on using electromyography (EMG) and volumetric magnetic resonance imaging (MRI) of the infraspinatus muscle to assess active global shoulder external rotation (GER) in neonatal brachial plexus palsy (NBPP).
  • Physical assessment of active GER in NBPP patients can be complemented by electrophysiological and imaging techniques.
  • Understanding the infraspinatus muscle's role is crucial for evaluating shoulder dysfunction in NBPP.

Purpose of the Study:

  • To evaluate the relationship between EMG and MRI findings of the infraspinatus muscle and active GER in NBPP patients.
  • To determine if infraspinatus muscle EMG interference patterns and MRI volume correlate with active GER outcomes.
  • To assess the utility of integrating EMG and MRI with clinical assessment for NBPP.

Main Methods:

  • A diagnostic study (Level II evidence) included 74 NBPP patients (age range: 1y1m to 13y3m).
  • Evaluations included physical examination of the shoulder, EMG of the infraspinatus muscle, and shoulder MRI.
  • Active GER was dichotomized (poor <0°, good ≥0°). EMG interference patterns were graded (≤4 poor, ≥5 good). Infraspinatus muscle volume was measured via MRI.

Main Results:

  • A poor EMG interference pattern in the infraspinatus muscle was significantly associated with poor active GER (odds ratio=7.391, P=0.0022).
  • Decreased infraspinatus muscle volume on MRI was also significantly related to poorer active GER (odds ratio=1.094 per % decrease, P=0.0413).
  • Both EMG interference pattern and muscle volume showed significant correlations with the Mallet Score for active GER.

Conclusions:

  • Infraspinatus muscle EMG interference patterns and MRI volume are strongly related to active GER, as assessed by the Mallet Score.
  • Integrating clinical assessment with electrophysiological (EMG) and imaging (MRI) findings can enhance diagnostic accuracy for shoulder dysfunction in NBPP.
  • These combined findings may improve guidance for selecting patient-specific interventions for NBPP.
Abstract

More Related Videos

Surface Electromyographic Biofeedback as a Rehabilitation Tool for Patients with Global Brachial Plexus Injury Receiving Bionic Reconstruction09:14

Surface Electromyographic Biofeedback as a Rehabilitation Tool for Patients with Global Brachial Plexus Injury Receiving Bionic Reconstruction

Published on: September 28, 2019

Methods for In Vivo Biomechanical Testing on Brachial Plexus in Neonatal Piglets06:51

Methods for In Vivo Biomechanical Testing on Brachial Plexus in Neonatal Piglets

Published on: December 19, 2019

Related Concept Videos

Spinal Nerves: Plexus I01:22

Spinal Nerves: Plexus I

Nerve plexuses are networks of interlacing nerves that serve as communication hubs to distribute and organize nerve action across various body regions. The nerve plexuses are organized into the cervical plexus located in the neck region, brachial plexus in the shoulder area, lumbar plexus found in the lower back, sacral plexus situated in the pelvis, and coccygeal plexus located in the coccygeal region.
The Cervical Plexus
The cervical plexus, formed by the anterior rami of the first four...
Magnetic Resonance Imaging01:24

Magnetic Resonance Imaging

Magnetic resonance imaging (MRI) is a noninvasive medical imaging technique based on a phenomenon of nuclear physics discovered in the 1930s, in which matter exposed to magnetic fields and radio waves was found to emit radio signals. In 1970, a physician and researcher named Raymond Damadian noticed that malignant (cancerous) tissue gave off different signals than normal body tissue. He applied for a patent for the first MRI scanning device in clinical use by the early 1980s. The early MRI...