You dont have bad bicep insertions, you just flex it wrong

[Deleted member 30188]

If this is how your bicep looks imma give you a tip
I want you to do this pose

then flex your bicep and you will feel a new head mainly the brachialis and short head, without these muscle the long head makes the bicep incomplete and people assume that the untrained brachialis is the tendon. This helped me with my biceps quite a bit growing them about .5 inches in about a month and making it look much fuller