Pressing problem

I am sure someone can help with this. When I am doing seated military presses behind the head, as I near the completion of my set My right arm is behind my body when I have the barbell fully extended above my head. In other words, looking up as I press,the barbell is diagonally above my head. My right arm slightly behind my torso and my left arm in line with my torso.
Does anyone have any ideas why this imbalance is occuring and what I can do to fix it? I have had a history of neck injuries(whiplash)and shoulder problems(trap strains, and rotator tears). Any help is appreciated. Thanks. Ken.

Is there a sliding or sinking feeling in the right shoulder at that point? If it hurts or looses a significant amount of strength suddenly there may be some underlying problem or injury (usually rotator, which you said you have injured). Neck injuries could contribute to poor form as the alignment of the spine allows for a complete transmission of the nerve impulse. If you have a crook in your neck you may feel a weak side or even a missfiring. I would see a doctor if you feel this is a possibility. Otherwise your form might just be horrible. I would cross my fingures for horrible form… do you have any imbalances in the upper back, chest, arms, or shoulders? That could contribute to poor form, the poor form also contributes to the imbalance. If it’s a rotator injury a physical therapist could help you strengthen it enough that you may be able to sustain a large amount of weight on it again. If it’s your neck, massage therapy even a chiropractor may be able to help you align it. As for horrible form get with a someone you know has good form and have them watch/spot you. I would really tackle the problem from all angles. If you can’t afford the visit to the Doc I would look into rotator cuff movements and make a program that specializes in that for at least 8 weeks. The neck thing I would look for a friend with some massage experiance and beg them to go to town on your neck and upper back. You will need to do a lot of stretching. Neck strengthening movements may also help. I also tore my rotator and when doing a military my right shoulder would slide back and down about 3/4 of the way through the movement. I did a lot of rotator strengthening on off training days and focused on lateral raises to develop strength and mass for a long time. Then I moved back to military and can lift almost as much as I can in a bench press with no pain and excellent form. My bench is a little weak because of the injury but I am working on that in exactly the same way I fixed my over head pressing movements. I’m sure that with time, caution, and patience you can do the same. Goodluck!