Longissimus Thoracis (Longiss R)
The M. Longissimus Thoracis (Longissimus Thoracis) is a muscle of the trunk posterior region. It is responsible for spinal extension and lateral flexion, stabilization of upright posture. This muscle is one of 26 with official SENIAM-recommended surface EMG electrode placement. This page documents the exact electrode position, anatomical attachments and a standardized test movement based on Hermens et al. (2000).
Spinal extension and lateral flexion, stabilization of upright posture
2 finger widths lateral to L1
Orientation: Parallel to the spine (vertical)
Hermens HJ, Freriks B, Disselhorst-Klug C, Rau G. Development of recommendations for SEMG sensors and sensor placement procedures. J Electromyogr Kinesiol. 2000;10(5):361-74.
Based on SENIAM recommendations (Hermens et al. 2000). Not an official SENIAM product. See all references →
Trunk extension from prone position against resistance
Common use cases for surface EMG measurement of the M. Longissimus Thoracis:
The electrode is placed — what next? easyEMG visualises muscle activity in real time, with SENIAM-compliant placement guidance, up to 4 channels at once and biofeedback training right afterwards.
In therapy, this muscle is usually about tone regulation and consciously relaxing below a threshold.
2 finger widths lateral to L1. Orientation: Parallel to the spine (vertical). Based on the official SENIAM recommendations (Hermens et al. 2000).
Trunk extension from prone position against resistance. This movement is part of the SENIAM protocol for standardized contraction verification.
Yes. The M. Longissimus Thoracis is one of 26 muscles for which the SENIAM project has published official surface EMG electrode placement recommendations.
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Open 3D Viewer →40 muscle protocols (SENIAM + peer-reviewed) on 80 pages, print-ready. Free via email.
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