The deltoid muscle is located on the outer side of the shoulder and is easily recognizable by its triangular shape; this muscle takes its name from the Greek letter Delta, which also has the shape of a triangle.
The deltoid is made up of three series of fibers: anterior, middle and posterior; they are connected by a thick tendon and are anchored in a V-shaped channel.
Deltoid muscle anatomy
The deltoid muscle is divided into:
- Anterior deltoid: starts from the lateral third of the clavicle; this part helps flex and rotate the humerus
- Lateral or middle deltoid: starts from the acromion of the shoulder; it helps abduct the humerus with its muscle fibers
- Posterior deltoid: starts from the spine of the scapula; this muscle extends and rotates the humerus and abducts it frontally and transversely.
Deltoid muscle functions
The deltoid muscle has the following functions:
- is responsible for all rotation of the arm
- allows you to keep items carried at a safer distance from the body
- has the task of stopping dislocation and injuries to the humerus when carrying heavy loads.
Common deltoid injuries
Le injuries to the muscles that make up the shoulder are very common for those who practice sports such as bodybuilding, martial arts or crossfit; in the specific case of the deltoid muscle, the pain almost always originates from a nearby muscle, such as the rotator cuff or the tendons of the long head of the biceps, which in the second phase also involve the deltoid.
- Dull pain indicates that we are probably facing a muscle tear
- Stinging during movement indicates an injury
More frequently, pain in the deltoid is caused by muscle strains, but sprains and dislocations can also be involved; in the case of athletes, pain can be caused by overexertion or by incorrect positioning of the joint.
If you experience pain in the shoulder, or any other muscle, stop exercising and always contact your doctor who will be able to give you all the specific indications of your case.
Exercises for the delts
Training the deltoid muscle in isolation is not as simple as you might think, because this muscle works in synergy with the back, pectoral and trapezius muscles.
Let's see some exercises aimed at training these muscles:
- Military press: this exercise can be performed with the barbell or dumbbells; start by loading the bar onto the rack or multipower for a more guided movement, hold the bar frontally with your wrists slightly wider than your shoulders and bring it under your chin, push up while keeping the forearms vertical and control the descent as you return to the starting position
- Side raises with dumbbells: while standing, grab the dumbbells with your palms towards your body and your arms at your sides, raise your arms until they are parallel to the ground, hold the position for a few seconds and then return to the starting position
- Pull-ups with neutral grip: grab the bar keeping the palms facing each other, push the shoulder blades against each other, raise the body until the chest touches the bar, check well the movement and the descent phase towards the starting position.
How do you train your deltoid muscles? What are your favorite exercises? Let us know in the comments and follow us on our telegram channel