After a day of throwing, the following day my bicept is sore. I have started throwing so its probably normal but thats why im asking. Also when I extend my arm fully, a patch of muscle on the outer body side bicept down low by the elbow hurts a little. Like I said befor just wondering if this is normal since my arm is not used to throwing
Most likely your Bicep muscle is not what’s sore. It’s probably the Brachiallis, which is another muscle that flexes the elbow. The Brachiallis is underneath the Bicep. This muscle has to work very hard when you throw, literally to keep your elbow from coming unhinged. I suspect that when you throw you take the ball behind you (in back of your torso, that is). Am I correct?
Suggestion: Pretend you are a pitcher and line up your shoulders on an imaginary line from home to second base. NEVER let the ball travel in back of this line. If you are right handed the ball should NEVER end up on the first base side of this line. If you are left handed the ball should NEVER end up on the third base side of this line.
When you take that ball beyond this imaginary line it it has a long way to go to come back into line so you can throw. This stresses the Brachiallis.
Let us know how it goes.
Do you have a video of yourself throwing?