Not-So-Gross Anatomy: Deltoids

"If the weight of the world is resting on your shoulders, they better be damn strong."

-Jeanette L. aka My Grandma


When I heard this statement I could not have been older than ten or eleven and I thought about this more literally than metaphorically. But boy, oh boy, was Jeanette on point with this statement in both contexts.

Metaphorically speaking, you need to be strong enough, callus enough, forgiving enough, and resilient enough to handle the obstacles that manifest during your laps around the sun. Literally speaking, if you have incredibly weak or imbalance shoulders, your quality of movement and upper body strength/power will be compromised.

Shall we talk deltoids? 

There are three heads to the deltoid group:


The anterior deltoids, the lateral deltoids, and the posterior deltoids all form the "shoulder". The anterior deltoid originates along the lateral end of the clavicle and inserts at the deltoid tuberosity on the humerus. When active, the anterior deltoids flexes and medially rotates the arm by pulling the humerus towards the clavicle.

The lateral (medial) deltoids originate at the acromion process of the scapulae and insert along the deltoid tuberosity of the humerus. The lateral (medial) deltoids abduct the arm by pulling the humerus toward the acromion.

Shoulder definition helps the arms and back look magnificent! We know delts at the b3 Lab!

Shoulder definition helps the arms and back look magnificent! We know delts at the b3 Lab!

The posterior (rear) head originate along the spine of the scapulae and insert at the deltoid tuberosity as well. Activation of the posterior (rear) deltoids extend and laterally rotate the arm by pulling the humerus toward the spine of the scapula.

The deltoids are interesting in that they are used for so many other movements. Many pulling actions done with the lats also include the posterior deltoids. Pressing movements that use the pectoralis major/minor also include the anterior & lateral deltoids. 

The anterior deltoid may very well be the most overused upper body muscles in the body. Think about your actions throughout a day. Do you brush your teeth? Eat a meal? Drive a car? Type on a computer? Scroll through your mobile? Push a door open? Push your chair away from a desk? Anterior deltoids are active through all of these. Poor posture and tight pectoral groups will alter the movement of the deltoids and this is mostly due to the "forward" leaning we do throughout the day.

With all of the activity to the anterior group, we need to give the posterior deltoids  some extra love throughout the week to help shape the shoulder and improve function.

Let's get into some mobility work:

Strength can be established through various modalities...let's see a few below to help round out the shoulders properly.

Overhead press work is a great way to develop deltoids. I do not care if it is barbells, kettlebells, dumbbells, bands, bodyweight, ViPR, or keg presses (sober, ideally) - an overhead press is a great grinding movement that will promote vertical strength and power and promote correct posture.

Supplementing the overhead press with lateral, front, and rear delt raises are tried and true to chisel out those deltoids. 

Knowing where and when to implement shoulder work into your routine is not a simple "one way" path. Assessing the mobility and strength of the delts, spinal posture, and yor goals all have a say in how we get after the deltoids at b3.


Thanks for reading this week's installment....see ya next time!


Be fit. Be fueled. Be full of life. b3 Wellness, llc

Don Bahneman MS, CSCS, CISSN, CPT, CHC