KNOW YOUR BODY / THE UPPER ARM

Triceps.
Anatomy &
movement.

Three heads. One connected path.
Attachments, movement, and observations to inform treatment planning.

Follow the anatomy

A Myostability education page

Palette-adapted historical right triceps attachment map. The long head begins on the scapula, the other heads on the humerus. The outlined muscle spans the back of the elbow to an attachment on the olecranon of the ulna. — Right arm · historical attachment map, not a surface view. Gold areas mark attachments; fine gold lines outline the muscle.
F. H. Gerrish, *Text-book of Anatomy* (1902), Fig. 311. Public domain · original image. Palette adapted to gold and charcoal; numbered labels added.

01 / ELBOW

Extension.

As the elbow straightens, the triceps path shortens. The tendon stays attached to the olecranon.

Shorter path · same attachment

Elbow extension schematic with the tendon attaching at the point of the elbow. — Triceps & tendon Bone POSITIONAL SCHEMATIC

02 / ELBOW

Flexion.

With the shoulder held still, bending the elbow lengthens the triceps path across the back of the joint.

Longer path · same attachment

Elbow flexion schematic with the forearm bent and tendon curving behind the elbow to the olecranon. — Triceps & tendon Bone POSITIONAL SCHEMATIC

03 / SHOULDER

Abduction.

Lifting the arm away from the body changes the long head’s relationship between scapula and upper arm.

Arm away from the body

Posterior shoulder abduction schematic showing the long head retaining its scapular origin. — Triceps & tendon Bone POSITIONAL SCHEMATIC

04 / SHOULDER

Adduction.

The arm returns toward the body. The triceps long head can assist this shoulder movement.

Arm toward the body

Posterior shoulder adduction schematic with the arm returned alongside the body. — Triceps & tendon Bone POSITIONAL SCHEMATIC

05 / SHOULDER

Rotation.

The humerus turns within the shoulder socket, changing the orientation of the upper arm and triceps.

Internal ↔ external rotation

Overhead schematic distinguishing shoulder internal and external rotation with the elbow bent. — Humerus turns · forearm follows POSITIONAL SCHEMATIC

06 / FOREARM

Pronation.
Supination.

The radius crosses the ulna in pronation and returns beside it in supination. The triceps stays attached to the ulna.

Two bones · changing relationship

Paired forearm schematics showing radius crossing ulna in pronation and lying beside it in supination. — Triceps & tendon Bone POSITIONAL SCHEMATIC

07 / PALPATION + SYMPTOM PATTERNS

Tenderness.
Trigger points.

Explore the heads. Separate where to assess from where symptoms may be felt.

Traditional reported patterns · broad assessment regions, not fixed point coordinates.

Long head

Local tenderness?Familiar symptoms?Movement affected?

TENDER POINT

Painful under pressure.

A descriptive finding: an area is tender when pressed. The term alone does not specify a taut band or a referral pattern.

MYOFASCIAL TRIGGER POINT

A cluster of findings.

A sensitive muscle spot assessed with a taut band and elicited symptoms. Active: reproduces familiar symptoms. Latent: may hurt or refer, without reproducing the familiar complaint.

Associated findings + evidence

Tenderness, familiar symptoms, stiffness, restricted movement, and reduced elbow-extension performance may be assessed across the triceps. These are not established as unique phenomena for individual heads. A local twitch response is not required.

The 2018 international Delphi consensus proposed at least two of three findings: a taut band, a hypersensitive spot, and referred symptoms. These are clinical assessment criteria, not an exact-coordinate test. Fernández-de-las-Peñas & Dommerholt, 2018.

Head-level symptom regions summarize traditional clinical descriptions in the Simons-coauthored triceps chapter collected by ScienceDirect: Triceps brachii muscle. Shading is original and broad; it is not a reproduction of a published trigger-point map. The medial head lies deeper and is shown as a surface assessment region, not a superficial muscle belly.

The lateral-head finger description is text-only; finger symptoms call for a broader assessment. Generic tenderness here is distinct from the historical fibromyalgia tender-point count.

ILLUSTRATIONS + REFERENCES

About these views

Original simplified positional schematics, not reconstructions or measured muscle-length simulations. The elbow pair holds shoulder position fixed. Shoulder abduction/adduction isolates the glenohumeral relationship and omits scapular motion. The original attachment map above remains the reference for the three heads.

Anatomy: University of Washington · NCBI: triceps · OpenStax: joint movements · Triceps muscle–tendon length study.