Related Experiment Video
Updated: Sep 25, 2026

Methods for In Vivo Biomechanical Testing on Brachial Plexus in Neonatal Piglets
Published on: December 19, 2019
Obstetric lesions of the brachial plexus
J G van Dijk1, W Pondaag, M J Malessy
1Department of Neurology and Clinical Neurophysiology, Leiden University Medical Centre, P.O. Box 9600, 2300 RC Leiden, Leiden, The Netherlands. vandijk@knf.azl.nl
Abstract:
The few studies on prognosis of obstetric lesions of the brachial plexus that are not hampered by selection bias or a short follow-up suggest that functional impairment persists in 20-25% of cases, more than commonly thought. Electromyography (EMG), potentially useful for prognosis, is often considered of little value. Denervation in the first week of life has been interpreted as evidence of an antenatal lesion, but is the logical result of the short axonal length affected. EMG performed at close to the time of possible intervention (3 months) usually shows a discrepancy: motor unit potentials are seen in clinically paralyzed muscles. This can be explained in five ways: an overly pessimistic clinical examination; overestimation of EMG recruitment due to small muscle fibers; persistent fetal innervation; developmental apraxia; or misdirection, in which axons reach inappropriate muscles. Further research into the pathophysiology of obstetric lesions of the brachial plexus is needed to improve prognostication.
Related Concept Videos
Sites for measuring blood pressure
The Brachial Artery: Primary Site for Blood Pressure Measurement
Bones of the Upper Limb: Ulna
Bones of the Upper Limb: Radius
The radius has a nail-shaped head, and a short...
Spinal Nerves: Plexus II
The Lumbar Plexus
The lumbar plexus is situated within the lumbar region of the back and is primarily formed by the first four lumbar spinal nerves (L1 to L4). This plexus extends its branches into several nerves, including the...
Arteries of the Upper Limbs
Veins of Upper Limbs
The deep venous system is primarily composed of the ulnar and radial veins. The ulnar vein, which drains the fingers through the superficial palmar venous arches, and the radial vein, which serves the palms via the deep palmar...

