What wrong with my motion

Hi, I’m not a baseball player nor have a I do any pitching before, I play tennis and I’m having same problem that started with my throwing motion. I have soreness in my lower bicep after throwing the ball for awhile which seems to be the Brachialis muscle getting sore. This happened all the time when I used to play dodgeball in high school for a few hours. Typically people throw out their shoulders and lower elbows but I always threw out my bicep. So I’m wondering if there is any issue with my actual motion that’s causing this or its just strengthening issue. Any feedback or suggestion would be much appreciated. The video has side and rear view. Thank you

Welcome to the forum but I’m having a tough time drawing a parallel between the tennis motion and the pitching motion. If you’re having biceps issues due to your tennis swing, my recommendation is to consult with a doctor or tennis trainer. In my experience, biceps issues for pitchers relate more to muscle imbalances and conditioning rather than biomechanics.

Thank you very much for the reply. The parallel for me is that the problem started with me throwing things, which now occurs in the same way in tennis. This made me wonder why the problem occurred in the first place. If you don’t see anything that causing it mechanically, then which muscle groups are typically imbalanced and need conditioning in this situation. Also, which exercises would you recommend doing to help it. Thanks again.

The tennis serve and pitching motion are just two completely different arm angles. Andy Roddick can serve 100 MPH but probably couldn’t throw 75 MPH. The reason your arm is hurting after throwing is because your arm isn’t conditioned at all for the mechanics of a throw because all you’ve been doing is playing tennis. Good luck and best to you.

Maybe look at following through and allowing your core to help with deceleration. Lots of arm stress is due to imbalance of deceleration muscles or the end of the kinetic chain.

Not exactly sure how it would translate to bicep pain but I don’t care for your glove arm motion. I think cocking it back and then swinging it around you leads to early shoulder rotation and, therefore, a sequencing problem whereby hip and shoulder rotation overlaps instead of hips rotating before shoulders. The result of all of this is that you don’t get much out of your body (hip and shoulder rotation is where much of your power comes from) so you try to make up for it with your arm.

Watch some of the video clips on this site and you’ll notice pitchers generally extend the glove arm forward - not rearward.