Anterior Deltoid: Functional Anatomy Guide

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Anterior Deltoid: Functional Anatomy Guide

The anterior deltoid (L. anterior, before, in front of ; deltoides, triangular) refers to the front head of the deltoid muscle. In this post you will find out everything you need to know about your anterior deltoid functional anatomy – shape (appearance), function (muscle action), location, insertion, and origin.

Introduction

Your shoulder muscles are called deltoids, or delts in gym jargon. The deltoids are two interesting muscles whose name means “triangular in outline”. There is one deltoid muscle in each of your shoulders.

Muscles of the anterior shoulder region

Muscles of the anterior shoulder region

The main shoulder muscle, the deltoid, is divided into three areas, or heads.
Anatomical and functional segments of the deltoid muscle:

  1. the anterior (front) deltoid;
  2. the lateral (side) deltoid;
  3. the posterior (rear) deltoid;

This three-part muscle wraps around the cap of the shoulder joint.

Other Names for Anterior Deltoid

  • Front Deltoid
  • Anterior head of the deltoid
  • Front of the shoulder
  • Front Delts

Anterior Deltoid: Location, Function, Origin, Insertion

The anterior division, also known as the anterior deltoid, is located on the front of your shoulder just above the chest muscles. More precisely, it is situated medial to the lateral deltoid and lateral to the clavicular head of the pectoralis major. When you get lean enough, you’ll be able to see all three heads contracting while you train. As you can see from the image above, deltoid muscle (and all its three heads) belongs to the group of muscles we call “muscles of the anterior shoulder region”.

Deltoid muscle animation
anterior head of the deltoid muscleEach head raises the arm in the direction for which it is named. The anterior (front) deltoid is involved in:

  • shoulder abduction (moving the arm away from the body),
  • flexion (moving the arm upward to the front),
  • transverse flexion (moving the arm across the chest), and
  • internal rotation (turning the arm inward).

The front (anterior) deltoid originates on the outer third of the collarbone (clavicle). The other two-thirds of the collarbone serves as the launching point for the uppermost fibers of the pectoralis major.

Because the fibers of the front deltoid originate alongside the fibers of the upper pectoralis major, the two muscles act like conjoined twins on chest presses. In other words, the front part of the shoulder muscle (the anterior deltoid) assists your pecs in their duties on pushups, dips, and bench presses. Perhaps you can feel this on yourself when you are performing bench press exercise. Don’t be surprised if you feel a bench press more in your front shoulders than in your chest.

Anterior deltoid muscle

Anterior deltoid muscle

Let’s summarise:

  • Muscle name: Anterior deltoid
  • Shape: Tiny strip of muscle (triangular in appearance)
  • Origin: Anterior surface of lateral third of clavicle
  • Insertion: Deltoid tuberosity of the lateral humerus
  • Action (function): Shoulder abduction, shoulder flexion, transverse flexion, shoulder internal rotation
  • Nerve supply: Axillary nerve (C5-C6)

Anterior Deltoids and Overtraining (Overdevelopment)

It’s common to have an imbalance among the three deltoid muscles. The anterior deltoids are often overdeveloped because of their constant involvement in chest exercises. Common lifts such as the front raise may constitute overkill, especially when you consider that the front deltoid is just a tiny strip of muscle – probably the smallest muscle on the body that a guy could specifically target. Furthermore, the front delt is also the area of the shoulder that responds best to weight training. The lateral and, especially, the rear delts are much more stubborn areas. They do gain strength, but toning them up is difficult. If that’s the case for you, focus on the middle and posterior (rear) deltoids when training the shoulders to minimize deltoid imbalances that could lead to injury.

Some shoulder exercises work all three parts of the deltoid in varying degrees, but most exercises target one head more than the others. Muscle proportion is critical in bodybuilding. If you develop one muscle—or a part of one muscle (head)—more than those around it, your physique is flawed. As you gain experience, pay attention to which areas seem to be developing faster than others so that you can adjust your regimen as necessary. Only by developing all three heads will you build strong, toned and rounded shoulders.

Anterior Deltoid Exercises

Because the front deltoid is only one part of your deltoid and your shoulder is the most complex joint in your body, it is impossible to isolate the anterior delt entirely. But you can perform exercises that recruit the muscle fibers more than others.

Front deltoid exercises fall into two main groups: shoulder presses (compound exercises) and front raises (isolation exercises). With presses, you lift weight directly over your head. Presses involve all three heads of the delt (especially front and middle). With front raises, you lift the weight in a wide arc to the front and strengthen the front head only. That is why it is important to structure shoulder workouts around basic multi-joint movements (such as the shoulder press) that hit all three heads as well as isolation exercises (such as front raise for the anterior head, lateral raise or upright row for the middle head, and rear deltoid raise for the posterior head).

But you have to keep in mind that exercises specifically for anterior deltoid, such as front raises, are usually not needed except for rehabilitation or specific strength training purposes. In the previous example, where the anterior deltoids overpower the other two deltoids, forgoing front raises in favor of lateral and bent-over laterals (rear laterals) is wise.

List of Compound and Isolation Exercises

  • Dumbbell front raise (one arm at a time)
    Dumbbell front raise (two arms at a time – simultaneously)
    Variable-grip dumbbell front raise
    Barbell front raise (standing)
    Incline barbell front raise
    Cable front deltoid raise (one arm at a time; D-attachment)
    Rope cable front raise
    Short straight bar cable front raise
  • Seated dumbbell shoulder press
    Seated barbell shoulder press (front military press)
    Behind the neck barbell shoulder press
    Machine shoulder press
    Arnold dumbbell press
    Smith machine shoulder press (front or back)
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