1. Schematic illustration of standard or coaxial bipolar (A), concentric bipolar (B), monopolar (C), single fiber needles (D and E), and Macro EMG (F). Dimensions vary, but the diameters of the outside cannulas shown resemble 26-gauge hypodermic needles (460 μm) for A, D, and E; a 23-gauge needle (640 μm) for B; and a 28-gauge needle (360 μm) for C and F. The exposed-tip areas measure 150 × 300 μm, with spacing between wires of 200 μm center to center for B; 0.14 sq mm for C; and 25 μm in diameter for D, E, and F. A flat-skin electrode completes the circuit with unipolar electrodes shown in C and D. For Macro EMG (F), a 10-mm side port is located behind the tip, exposing a 25-g diameter platinum wire. Macro EMG recording is made on one channel from the side port electrode with the cannula as reference (ordinary single-fiber EMG recording), and other channel potentials are recorded between the cannula and a remote subcutaneous concentric needle electrode as reference, placed at least 30 cm away. Contribution from all muscle fibers in a motor unit is extracted using spike-triggered averaging from the two channels.
Source: Neuromuscular, The Rehabilitation Specialist's Handbook, 4e
Citation: Roy SH, Wolf SL, Scalzitti DA. The Rehabilitation Specialist's Handbook, 4e; 2013 Available at: Accessed: October 14, 2017
Copyright © 2017 McGraw-Hill Education. All rights reserved