This is an excerpt from Delavier's Anatomy for Bigger, Stronger Arms by Frederic Delavier & Michael Gundill.
Four Obstacles to Developing the Biceps
You must overcome four problems in order to develop biceps. After reviewing these obstacles, we will explain how to move past them.
This is the main frustration for many people in strength training. Even though you can never have big enough biceps, some people's arms just seem resistant to growth. Visually, small biceps can be dwarfed by large shoulders. The situation is not hopeless. There are innovative strat-egies, often overlooked, that can help you develop your biceps quickly.
A biceps muscle is short when it stops very high above the forearm; this is often the reason for poor muscle development. On the contrary, people with very long biceps (that come far down on the forearm) have an easier time developing the muscle.
The only advantage of short biceps is that they have a better peak (the summit of your biceps when con-tracted). Long biceps have a less pronounced peak.
Unfortunately, you cannot lengthen your biceps. But even though you cannot make your biceps go lower down on your forearm, it is possible to make your forearm climb toward your biceps by developing the brachioradialis (the muscle that joins the biceps and the forearm).
Imbalance Between the Long and Short Heads
The long and short heads are not always equally developed. You can see this asymmetry when you contract both biceps:
- Seen from the front, a lack of curve and a small peak mean the short head is deficient.
- Seen from the back, a lack of curve means the long head is lacking.
To resolve this problem, you must isolate the work to the head that is lacking.
The brachialis is often underdeveloped. So this is easy mass for you to gain. The brachialis muscle's impact on your appearance does not stop there:
- If one arm is bigger than the other, the size difference is often because the brachialis is more developed in one arm than the other.
- Genetics, in large part, determine the form of the biceps, so a large brachialis can improve the peak by pushing the biceps up.
The problem with the brachialis is not that it develops poorly. More often, it suffers from poor motor recruitment. Many people do exercises that are supposed to work the brachialis without the muscle actually working. You must teach the brachialis to contract by doing specific work on motor learning.