Brachialis

The brachialis muscle is a strong, flat muscle located in the upper arm. It is considered a pure elbow flexor because its action is not affected by the position of the forearm or wrist.

The brachialis muscle lies deep beneath the more prominent biceps brachii muscle, which is also involved in elbow flexion. Both muscles work together during elbow flexion, but the brachialis muscle provides the majority of the force.

Proper functioning of the brachialis muscle is essential for activities requiring arm strength and mobility, such as lifting, climbing, and throwing.

Brachialis

Anatomy

[Origin]

Distal half of anterior surface of Humerus

[Insertion]

Coronoid process and tuberosity Ulna

[Action]

Flexes forearm in all positions

Clinical Relevance

Brachialis Injuries

The brachialis muscle can be commonly injured by repetitive forceful contractions or muscular contractions with the arm in hyperextension. This is commonly seen in climbers, due to the pronation of the hand and the extended started position.

A strain to the brachialis tendon can also cause a patient to present with lacking elbow extension due to painful end-range stretching of the tendon.

~ Evidence-Based Exercises ~

According to an EMG study, the exercises that demonstrated significant muscle contractions of Brachialis are;

Preacher Curl
Pull-Up
Cross-Over Dumbbell Curl

Preacher Curl

Pull-Up

Cross-Over Dumbbell Curl

< Reference >

Keith L. Moore, Anne M. R. Agur, Arthur F. Dalley. Moore Clinically Oriented Anatomy 7^th Edition, Lippincott Williams & Wilkins, 2013
Bond T. Tom’s Physiotherapy Blog: “Climber’s elbow” – Brachialis Tendonitis [Internet]. Tom’s Physiotherapy Blog. 2013 [cited 2018 Mar 21]
Kamineni S, Bachoura A, Behrens W, Kamineni E, Deane A. Distal insertional footprint of the brachialis muscle: 3D morphometric study. Anatomy Research International. 2015;2015.
Marieb EN, Hoehn K. Human anatomy & physiology. 10th ed. Boston, Ma: Pearson; 2016