Per Donnelly et al. 2025 Forearm Left

M. Flexor Carpi Ulnaris

Flexor Carpi Ulnaris (FCU L)

The M. Flexor Carpi Ulnaris (Flexor Carpi Ulnaris) is a muscle of the forearm region. It is responsible for wrist palmar flexion and ulnar abduction. 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

Wrist palmar flexion and ulnar abduction

Opposite side: FCU R

Electrode position on the 3D model: M. Flexor Carpi Ulnaris (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)

50% on line from medial epicondyle to Os pisiforme

Orientation: Parallel to the ulna

Source: Donnelly et al. 2025 ↗

Donnelly T, Routledge N, Seminati E, Metcalfe B. A method for locating surface electromyography electrodes on the flexor carpi ulnaris. J Electromyogr Kinesiol. 2025;82:103010.

Methodological background of the source

Donnelly et al. (2025) describe a reproducible method for locating electrodes on the flexor carpi ulnaris using palpable landmarks. The muscle lies at the ulnar border of the forearm close to other flexors — the method aims to minimize crosstalk and make the position comparable between examiners.

Recording notes per Criswell 2011, site „Flexor Carpi Ulnaris“, p. 331

Placement type: Quasi-specific site Neighbouring muscles contribute noticeably to the signal — allow for crosstalk.
Signal check: Flex and ulnar-deviate the wrist.
Crosstalk from: flexor digitorum superficialis

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

Go deeper Specific, Quasi-Specific, General — The Three Types of Surface EMG Placement → Can I Measure This Muscle With Surface EMG? →

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 Medial epicondyle of the humerus, olecranon, proximal ulna Insertion Os pisiforme, Os hamatum, base of the 5th metacarpal

Test Movement

Wrist flexion with ulnar 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 kneeling in front of a bench with the forearm resting on a stable support.
Fixation: Forearm fully supported; wrist free to work against the resistance.
Resistance: Manual resistance, a barbell or a cable/belt against the wrist or hand.
Control exercise: Use the latissimus dorsi and pectoralis major tests as control exercises.

Konrad treats the forearm flexors and extensors as one group; wrist flexion for the flexors, wrist extension for the extensors.

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. Flexor Carpi Ulnaris 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. Flexor Carpi Ulnaris?

50% on line from medial epicondyle to Os pisiforme. Orientation: Parallel to the ulna. Not covered by SENIAM — placement per Donnelly et al. 2025.

Which test movement activates the M. Flexor Carpi Ulnaris?

Wrist flexion with ulnar 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. Flexor Carpi Ulnaris a SENIAM-recommended muscle?

No. The M. Flexor Carpi Ulnaris is not included in the official SENIAM catalogue. The electrode position documented here follows the established protocol per Donnelly et al. 2025.