What’s Underneath… Arm Muscles (Posterior)

Welcome back to the latest post in my What’s Underneath Series, which introduces you to some easy learning about human anatomy – in particular the muscles of the body – along with my top exercise picks for strengthening these muscles. My last post talked about the anterior muscles of the arm, and now we’re going to move posterior. The triceps brachii is the antagonistic or opposing muscle to the biceps brachii. When either one of these muscles contract – the biceps to flex the arm and the triceps to extend it – these muscles work against each other.

Image taken from teachmeanatomy.com.

Triceps Brachii

Just like there are multiple heads to the biceps brachii, the triceps brachii contains a long, lateral and medial head. The medial head lies below the long and lateral heads. The long head attaches to the scapula, and the medial and lateral heads attach to the humerus. All three heads then converge into one, where they eventually all join onto the ulna of the forearm. The overall function of the triceps brachii is to extend the arm at the elbow, it fixates the elbow when steady, fine hand movements are needed, and it works against the action of the biceps and its synergists (aiding muscles).

Some good triceps brachii workouts:

Rope Tricep Pushdown

Image taken from menshealth.com. View full exercise instructions here.

Tricep Dips

Image taken from menshealth.com. View full exercise instructions here.

Overhead Triceps Extension

Image taken from menshealth.com. View full exercise instructions here.


1) Teachmeanatomy.info. (2019). Muscles of the Upper Arm – Biceps – Triceps – TeachMeAnatomy. [online] Available at: https://teachmeanatomy.info/upper-limb/muscles/upper-arm/ [Accessed 25 May 2019].

2) Men’s Health. (2019). Tricep Exercises: 10 of the Best to Build Muscle. [online] Available at: https://www.menshealth.com/uk/building-muscle/a759179/tricep-exercises-best-build-muscle/ [Accessed 25 May 2019].

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.