Hey guys, i have an issue with my biceps. Currently it seems like my biceps on each arm is shaped differently. My right bicep is big seems to be build all the way down to where the muscle meets the elbow. My left bicep on the other hand is different. On the left the upper bicep is build nicely and the lower looks undeveloped, so much that it looks nice by the shoulder and then further down the arm it looks almost flat by where the muscle meets the elbow. How did this happen? How do I fix this? It has frustrated me for a while and I want to know what exercises to do to isolate my lower bicep to build it the right way.

Any answers?