Everyone wants bigger arms, but there’s no such thing as a magical workout you can do to get them.
Let´s see the most important muscles:
The Coracobrachialis is a long, slender muscle of the shoulder joint.
The contraction of the coracobrachialis leads to two movements at the shoulder joint. On one hand, it bends the arm (flexion), and on the other hand, it pulls the arm towards the trunk (adduction). To a smaller extent, it also turns the humerus inwards (inward rotation). Another important function is the stabilization of the humeral head within the shoulder joint, especially when the arm is hanging freely straight down.
Origin:
Coracoid process of the scapula.
Insertion:
The medial shaft of the humerus at about its middle.
The overuse of the coracobrachialis can lead to stiffening of the muscle. Common causes of injury include chest workouts or activities that require pressing the arm very tight towards the body, e.g. work on the rings in gymnastics. Symptoms of overuse or injury: pain in the arm and shoulder, radiating down to the back of the hand.
The Biceps brachii, commonly known as the biceps, is a two-headed muscle that lies on the upper arm between the shoulder and the elbow. The Biceps muscle is actually two separate bundles of muscles (heads). The two heads of the Biceps vary in length and as a result, are called the Short and the Long Biceps heads.
Origin:
- Long head- supraglenoid tubercle and glenohumeral labrum.
- Short head- tip of the coracoid process of the scapula.
Insertion:
- Radial tuberosity.
- Bicipital aponeurosis.
The biceps works across three joints.
Proximal radioulnar joint (upper forearm): It functions primarily as a powerful supinator of the forearm (turns the palm upwards). This action, which is aided by the supinator muscle requires the elbow to be at least partially flexed.
Humeroulnar joint (elbow): It also functions as an important flexor of the forearm, particularly when the forearm is supinated. This action is performed when lifting an object, such as a bag of groceries. When the forearm is in pronation (the palm faces the ground), the brachialis, brachioradialis, and supinator function to flex the forearm, with minimal contribution from the biceps brachii.
Glenohumeral joint (shoulder): TIt weakly assists in forward flexion of the shoulder joint (bringing the arm forward and upwards). It also contributes to abduction (bringing the arm out to the side) when the arm is externally (or laterally) rotated. The short head also assists with horizontal adduction (bringing the arm across the body) when the arm is internally (or medially) rotated. Finally, the short head, due to its attachment to the scapula (or shoulder blade), assists with stabilization of the shoulder joint when a heavy weight is carried in the arm.
The brachialis is a muscle in the upper arm that flexes the elbow joint. It lies deeper than the biceps brachii and is a synergist that assists the biceps brachii in flexing at the elbow.
Origin:
- Lower 1/2 of anterior humerus.
- Both intermuscular septa.
Insertion:
- Ulnar tuberosity.
- Coronoid process of ulna slightly.
Its primary action is to flex the forearm muscles at the elbow. Due to its high contractile strength, the branchialis makes many arm and elbow movements possible. Such movements are important for the activities of daily life. Because movements involving the arms and elbows are almost always continuous, injuries to the brachialis muscle are quite common.
The Triceps Brachii muscles are located on the back of the humerus and more commonly referred to as the triceps. The triceps muscles have three muscle heads: Lateral, Medial and Long head.
Origin:
- Long head: infraglenoid tubercle of the scapula.
- Lateral head: upper half of the posterior surface of the shaft of the humerus, and the upper part of the lateral intermuscular septum.
- Medial head: posterior shaft of humerus, distal to radial groove and both the medial and lateral intermuscular septum (deep to the long & lateral heads).
Insertion:
- Posterior surface of the olecranon process of the ulna.
- Deep fascia of the antebrachium.
Primarily responsible for the extension of the elbow joint (straightening of the arm). It can also fixate the elbow joint when the forearm and hand are used for fine movements, e.g., when writing. The lateral head is used for movements requiring occasional high-intensity force, while the medial fascicle enables more precise, low-force movements.
With its origin on the scapula, the long head also acts on the shoulder joint and is also involved in retroversion and adduction of the arm.
The anconeus muscle (or anconaeus/anconæus) is a small muscle on the posterior aspect of the elbow joint.
Origin:
Posterior surface of the lateral epicondyle of the humerus.
Insertion:
Lateral aspect of olecranon extending to the lateral part of ulnar body.
It assists in extension of the elbow, where the triceps brachii is the principal agonist, and supports the elbow in full extension. It also prevents the elbow joint capsule being pinched in the olecranon fossa during extension of the elbow. Anconeus also abducts the ulna and stabilizes the elbow joint. Anconeus serves to make minute movements with the radius on the ulna. In making slight abduction of the ulna, it allows any finger to be used as a axis of rotation of the forearm.
Activities That Cause Pain and Symptoms of the Anconeus
– Forced and repetitive gripping of a large and/or wide object
– Extreme sudden hard extension (straightening) of the elbow
– Pushing a door closed
– Rotating arm to shake hands
– Golfing (non-dominate arm)
– Tennis (dominant arm)
– Rowing motions