Per Boettcher et al. 2008 Shoulder Right

M. Infraspinatus

Infraspinatus (Infra R)

The M. Infraspinatus (Infraspinatus) is a muscle of the shoulder region. It is responsible for external rotation at shoulder joint, stabilization of humeral head (rotator cuff). 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

External rotation at shoulder joint, stabilization of humeral head (rotator cuff)

Opposite side: Infra L

Electrode position on the 3D model: M. Infraspinatus (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)

4cm below spine of scapula, over infraspinous fossa

Orientation: Parallel to spine of scapula

Source: Boettcher et al. 2008 ↗

Boettcher CE, Ginn KA, Cathers I. Standard maximum isometric voluntary contraction tests for normalizing shoulder muscle EMG. J Orthop Res. 2008;26(12):1591-7.

Methodological background of the source

Boettcher et al. (2008) defined standardized maximum isometric voluntary contraction (MVIC) tests for normalizing shoulder EMG and specified the electrode positions of the shoulder muscles studied. The position used here comes from that normalization protocol — it is designed for reproducible comparisons between sessions and subjects.

Recording notes per Criswell 2011, site „Infraspinatus“, p. 302

Placement type: Specific site The signal originates predominantly from this muscle.
Crosstalk from: posterior deltoid · teres major · teres minor
Artefacts: ECG.

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

Go deeper Which Muscles Cannot Be Measured With Surface EMG — and Why → Specific, Quasi-Specific, General — The Three Types of Surface EMG Placement →

All 47 muscle protocols as a PDF — free

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

Origin Infraspinous fossa of scapula Insertion Greater tubercle of humerus (middle facet)

Test Movement

External rotation of arm at 90 degrees abduction against resistance

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

MVC reference test (Konrad 2005)

Position: Seated or standing, elbow at 90° and held at the side, forearm pointing forward.
Fixation: Elbow kept at the trunk (towel between arm and body helps).
Resistance: Uni- or bilateral manual resistance against the forearm, external rotation against it.

As the most important external rotator of the cuff, any related external-rotation task works.

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

Measure M. Infraspinatus 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 rehabilitation, the Infraspinatus is typically recorded to track progress and retrain activation.

EMG biofeedback in physiotherapy → What is EMG biofeedback?

Frequently Asked Questions

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

4cm below spine of scapula, over infraspinous fossa. Orientation: Parallel to spine of scapula. Not covered by SENIAM — placement per Boettcher et al. 2008.

Which test movement activates the M. Infraspinatus?

External rotation of arm at 90 degrees abduction against resistance. It serves as a signal check before recording: with correct electrode placement the EMG amplitude rises clearly during this movement.

Is the M. Infraspinatus a SENIAM-recommended muscle?

No. The M. Infraspinatus is not included in the official SENIAM catalogue. The electrode position documented here follows the established protocol per Boettcher et al. 2008.