Per Criswell 2011 Head & Neck Left

M. Masseter

Masseter (Masseter L)

The M. Masseter (Masseter) is a muscle of the head & neck region. It is responsible for jaw closure (elevation of the mandible), grinding during mastication. This muscle is not covered by the official SENIAM catalogue — placement is based on established clinical literature. This page documents the exact electrode position, anatomical attachments and a standardized test movement based on Hermens et al. (2000).

Function

Jaw closure (elevation of the mandible), grinding during mastication

Opposite side: Masseter R

Electrode position on the 3D model: M. Masseter (muscle highlighted, sensor in place)

Preview — open the 3D viewer to rotate the model and check neighbouring muscles. View in 3D Viewer

Electrode Placement (SENIAM)

Over the muscle belly at the angle of the jaw — palpate while the person clenches the teeth and place the electrodes over the clearly protruding belly

Orientation: Along the muscle fibres, 2 cm inter-electrode distance; place the pairs symmetrically when comparing sides

Source: Criswell 2011

Criswell E. Cram's Introduction to Surface Electromyography. 2nd ed. Jones & Bartlett Learning; 2011. ISBN 978-0-7637-3274-5.

Methodological background of the source

Criswell (2011) — Cram's Introduction to Surface Electromyography, 2nd edition — is the standard textbook for surface EMG electrode placement beyond the SENIAM catalogue. Its atlas section (Part III) describes, for each site, palpation, electrode location with 2 cm spacing parallel to the fibres, a behavioural test and the neighbouring muscles from which crosstalk is to be expected. Cram's classifies the position used here as "quasi-specific" — the muscle cannot be fully separated from its neighbours at the surface. The position is established in practice but less validated than a SENIAM recommendation.

Recording notes per Criswell 2011, site „Masseter“, p. 270

Placement type: Specific site The signal originates predominantly from this muscle.
Signal check: Clench the teeth; also check swallowing and talking.
Crosstalk from: lateral pterygoid · buccinator · zygomaticus
Artefacts: Swallowing and talking produce their own bursts — exclude both when analysing.

Based on SENIAM recommendations (Hermens et al. 2000). Not an official SENIAM product. See all references → · How electrodes are placed (guide) · Glossary

Go deeper Why the Electrode Must Not Sit on the Innervation Zone → 10 Factors That Distort Your EMG Signal →

All 49 muscle protocols as a PDF — free

Print-ready for the lab or clinic: 85 pages of protocols (SENIAM + peer-reviewed), plus the SENIAM table, a placement checklist and a sensor comparison sheet as A4 sheets.

Anatomy

Origin Zygomatic arch Insertion Lateral surface of the ramus of the mandible, superior half Innervation Masseteric nerve from the mandibular division of the trigeminal nerve (V3)

Innervation after Perotto AO, Anatomical Guide for the Electromyographer, 5th ed. 2011 — an anatomical reference, not an electrode placement recommendation.

Test Movement

Clench the teeth firmly

This muscle has no SENIAM-standardized electrode position. Placement should be based on anatomical knowledge.

Measure M. Masseter 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.

EMG biofeedback in therapy → What is EMG biofeedback?

Frequently Asked Questions

Where do I place the EMG electrode on the M. Masseter?

Over the muscle belly at the angle of the jaw — palpate while the person clenches the teeth and place the electrodes over the clearly protruding belly. Orientation: Along the muscle fibres, 2 cm inter-electrode distance; place the pairs symmetrically when comparing sides. Not covered by SENIAM — placement per Criswell 2011.

Which test movement activates the M. Masseter?

Clench the teeth firmly. It serves as a signal check before recording: with correct electrode placement the EMG amplitude rises clearly during this movement.

Is the M. Masseter a SENIAM-recommended muscle?

No. The M. Masseter is not included in the official SENIAM catalogue. The electrode position documented here follows the established protocol per Criswell 2011.