Understanding the Anatomy of Biceps and Triceps for Effective Upper Arm Training
Your biceps and triceps are your show muscles. Whether you’re wearing a t-shirt or a suit, there’s no hiding a pair of loaded guns. By the same token, you can’t cover up puny arms. Creating impressive upper arms takes more than pumping heavy iron. You must also understand your bis and tris’ biomechanics, anatomy, and function. In this article, we’ll give you everything so you can train harder and smarter.
Anatomy and Function — Biceps vs. Triceps
Before we get into upper arm anatomy, let’s take a moment to talk about why you need to know this stuff. After all, you’re not training to be a doctor; you simply want to make your arms bigger. Well, it turns out that understanding the anatomy of your bis and tris is essential to ensure that you’re making your hard work in the gym count. By understanding their origin, insertion points, and movement patterns, you’ll know which exercises to choose and which to avoid to work them most effectively.
Biceps Anatomy
The biceps’ primary function is to flex the elbow. Two smaller muscles, the brachialis, and brachioradialis, assist only to a small extent. Biceps also help raise your arm forward, but this is mainly down by the front deltoid. The biceps comprises two muscle heads, the short and long. The short biceps head originates from the coracoid process of the scapula (that’s the inner part of the outer tip of the shoulder blade). The long head originates on the glenoid tubercle of the scapula (the outer part of the outer tip of the shoulder blade). The important point to note is that both the short and long heads have a single insertion point, converging to cross the elbow and attaching to the radius (the smallest of the two forearm bones).
Why is that important? When you bend your elbow, you involve both the long and short biceps heads. That’s because they both pass through the elbow joint. Remember, too, that the elbow is a single hinge joint; it can only move in one direction. Think about what that means. You have been fooling yourself if you’ve been doing specific exercises to hit the long head of the biceps and others to target the short head. When it comes to working the biceps, it’s all or nothing. Both heads are pulling on the same tendon in the same direction. It’s a common belief that you can work the long and short heads separately to change the shape of your biceps. Yet, a simple look at anatomy shows that that’s impossible! It doesn’t matter whether you’re doing curls with an EZ curl bar, a straight-arm dumbbell, cables, a preacher bench, a hammer grip, or any other variation; both biceps heads will work together to flex your elbow.
Ideal Movement for Biceps Development
Because your elbow only does one thing, your only way to work the bicep is to bring your hand toward your shoulder, which requires elbow flexion. The position of your elbow in relation to your body is important. You’ve probably seen people doing cable curls with their elbows at their sides, and preacher curls with them in front of the torso. Even though the elbow is in different positions, the actual biceps movement is the same. So, you won’t get any extra benefit to that muscle from these variations. When you begin a curl with your arm out vertically and your elbows straight (as when doing a high cable curl), you put way too much stress on the biceps tendon. This makes you very susceptible to a biceps tendon rupture. Hence, I recommend not doing this exercise. The most natural position is to have your elbows at your sides, like in the standing dumbbell curl. This position does the best job of aligning with the strength curve of the biceps. According to that strength curve, the muscle is strongest at the beginning of the curl and weakest at the end of the movement.
Triceps Anatomy
The biceps and triceps are antagonistic muscles. That means that when one flexes, the other relaxes. The triceps also move the elbow in the opposite direction to the biceps. So, its main job is to extend the elbow (the opposite of flexion). In simple terms, the triceps straighten your arm. The triceps have three heads, hence the name. Like the biceps, the different heads have separate points of origin but the same insertion point. The three triceps heads are the following: The lateral and medial heads originate on the back of the upper arm (humerus), just below the shoulder joint. The long head originates on the scapula, or shoulder joint, just under the shoulder socket. Because of this, the long head has minimal involvement when you pull your arm down. However, its main job, along with the other two heads, is elbow extension.
All three triceps heads insert on the ulna (the largest forearm bone). So, just as we’ve seen with the biceps, all three heads are involved when you perform a triceps exercise. You cannot do an exercise to isolate your long head, just like you can’t do one to hit the short head of the biceps. While it’s true that doing an overhead triceps movement, such as the overhead cable triceps extension, will pre-stretch the long head of the triceps more than the other two heads, there is no connection between pre-stretching a muscle and making it stronger or bigger. So, there is no benefit to using an overhead position when working your triceps. The best elbow position for the triceps is the same as for the biceps alongside the body. This is the most natural and the most comfortable position. Many people experience elbow pain from overhead triceps work; now you know you don’t have to!
Ideal Resistance Direction for Triceps Development
The exercise with the best direction of movement for the triceps will follow the strength curve of the muscle. That means it will be harder at the beginning and easier at the end.
