The M. Trapezius Pars Descendens (Upper Trapezius) is a muscle of the head & neck region. It is responsible for elevation of scapula, lateral flexion of cervical spine, head extension. 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).
Function
Elevation of scapula, lateral flexion of cervical spine, head extension
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.
Recording notes per Criswell 2011, site „Upper Trapezius (Narrow)“, p. 289
Placement type
Specific site The signal originates predominantly from this muscle.
Signal check
Shoulder elevation (shrug) or lateral bending of the head.
Print-ready for the lab or clinic: 75 pages of protocols (SENIAM + peer-reviewed), plus the SENIAM table, a placement checklist and a sensor comparison sheet as A4 sheets.
Anatomy
OriginExternal occipital protuberance, Lig. nuchae, Proc. spinosi C1–C7InsertionLateral third of clavicle, acromion
Test Movement
Elevate shoulder against resistance (shoulder shrug)
Illustration shows the left side; the set-up is mirrored for the right side.
MVC reference test (Konrad 2005)
Position
Seated, arms hanging at the side; the test can be done on one side only.
Fixation
Arm fixed downwards: manually, with a strap to the floor, or by holding a load heavy enough to press the shoulder down.
Resistance
Shoulder elevation (shrug) against the fixed arm.
Konrad calls the load variant "difficult" — the load has to be heavy enough that the shoulder cannot rise.
Konrad P. The ABC of EMG. Noraxon; 2005, p. 31. Konrad describes this test at group level; it applies to all muscles of the group. · Why and how to normalise to MVC
Clinical Applications
Common use cases for surface EMG measurement of the M. Trapezius Pars Descendens:
Jaw rehabilitation and TMJ disorders
Cervical posture analysis and muscle tension
Headache biofeedback (cervicogenic, tension-type)
Measure M. Trapezius Pars Descendens activity live
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.
Where do I place the EMG electrode on the M. Trapezius Pars Descendens?
50% on line from acromion to C7 spinous process. Orientation: Toward acromion–C7 line. Based on the official SENIAM recommendations (Hermens et al. 2000).
Which test movement activates the M. Trapezius Pars Descendens?
Elevate shoulder against resistance (shoulder shrug). This movement is part of the SENIAM protocol for standardized contraction verification.
Is the M. Trapezius Pars Descendens a SENIAM-recommended muscle?
Yes. The M. Trapezius Pars Descendens is one of 26 muscles for which the SENIAM project has published official surface EMG electrode placement recommendations.
Preview — open the 3D viewer to rotate the model and check neighbouring muscles.
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