SENIAM recommended Thigh Posterior Right

M. Biceps Femoris Caput Longum

Biceps Femoris (Long Head) (BF Long R)

The M. Biceps Femoris Caput Longum (Biceps Femoris (Long Head)) is a muscle of the thigh posterior region. It is responsible for knee flexion, hip extension and external rotation, external rotation of the lower leg with flexed knee. 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

Knee flexion, hip extension and external rotation, external rotation of the lower leg with flexed knee

Opposite side: BF Long L

Electrode position on the 3D model: M. Biceps Femoris Caput Longum (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 between ischial tuberosity and lateral epicondyle

Orientation: Parallel to line ischial tuberosity-lateral epicondyle

Source: SENIAM (Hermens 2000) ↗

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 „Medial and Lateral Hamstring“, p. 369

Placement type: Specific site The signal originates predominantly from this muscle.
Signal check: Prone: flex the knee against resistance; standing: flex the knee.
Crosstalk from: medial hamstrings · quadriceps

The position above follows SENIAM; the crosstalk and artefact notes apply to surface recording of this muscle in general.

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 → Which Muscles Cannot Be Measured With Surface EMG — and Why →

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 Ischial tuberosity (together with M. semitendinosus) Insertion Fibular head, lateral tibial condyle

Test Movement

Knee flexion in prone position against resistance with foot external rotation

MVC reference test (Konrad 2005)

Position: Prone, unilateral knee flexion held at about 20–30° knee flexion.
Fixation: Very good hip fixation (belt or a heavy person holding the pelvis).
Resistance: Manual resistance or strap at the heel, knee flexion against it.
Control exercise: The prone erector spinae test is the important check exercise.

Konrad tests the hamstrings as one group ("Mm. ischiocrurales"); surface EMG does not separate the medial and lateral heads well.

Konrad P. The ABC of EMG. Noraxon; 2005, p. 32. 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. Biceps Femoris Caput Longum:

Hamstring injury prevention
Sprint and athletic movement analysis
Post-ACL rehabilitation

Measure M. Biceps Femoris Caput Longum 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 training, what matters for this muscle is targeted activation and left/right symmetry.

EMG biofeedback training → What is EMG biofeedback?

Frequently Asked Questions

Where do I place the EMG electrode on the M. Biceps Femoris Caput Longum?

50% on line between ischial tuberosity and lateral epicondyle. Orientation: Parallel to line ischial tuberosity-lateral epicondyle. Based on the official SENIAM recommendations (Hermens et al. 2000).

Which test movement activates the M. Biceps Femoris Caput Longum?

Knee flexion in prone position against resistance with foot external rotation. This movement is part of the SENIAM protocol for standardized contraction verification.

Is the M. Biceps Femoris Caput Longum a SENIAM-recommended muscle?

Yes. The M. Biceps Femoris Caput Longum is one of 26 muscles for which the SENIAM project has published official surface EMG electrode placement recommendations.