Definition for Ladies Spring 2014 Issue 001 April 2014 | Page 78

DEFINING

DELTOIDS

An insightful look into the anatomy of the shoulder muscle
by Erin Fergus
You may have heard women talk about

next to each other) that divide it into

during a straight arm pull down for the

building up their “delt caps” and won-

three aspects: anterior, medial and pos-

lats) and pushing the arms back behind

dered what the heck that meant. If you

terior. One reason that the deltoids are

the hips. It is also the agonist for shoul-

are a physique competitor, you are deep

not as strong as other muscles is because

der horizontal abduction, which is the

in the process of making that happen.

of this fiber arrangement. Second, the

motion of taking the arms from out in

The deltoid muscle creates a round

entire muscle is smaller than other

front at chest height to out to the sides

“cap” on top of the shoulder that sticks

muscles such as the pectoralis major,

(such as a rear delt fly machine.) This

up and out slightly, and it creates shape

latissimus dorsi and triceps brachii.

motion can also be performed holding

and definition in the upper arm by
making the division between the shoulder and biceps more pronounced (that

The anterior aspect is the agonist, or
prime moving muscle, during shoulder

dumbbells and bent over at the waist
with a flat back.

flexion, which is raising the arm up to

Where should deltoid work fall into

the front. It also works as a synergist,

your training plan? There is no “right”

or assisting muscle, when performing

or “wrong” answer because the decision

pressing movements such as the chest

aligns with your goals. Someone who

press. The medial aspect is the agonist

wants healthy, strong, balanced shoul-

for shoulder abduction, which is rais-

ders might train them less and paired

ing the arms out to the side laterally,

with different muscle groups than

and the anterior and posterior aspects

someone with aes F